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Interview with “Best Poster Award” Winner at 2023 Research Showcase: “Properties of Cementitious Materials with Reclaimed Cement”

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Concrete production is energy intensive, and requires materials that are both challenging, and expensive to acquire. Material engineers are seeking alternative materials that are more cost-effective and carbon-friendly, but also operate successfully as road and building material.  

We spoke with Alyssa Yvette Sunga, a graduate researcher at Rowan University who won the Best Student Poster Award at NJDOT’s 2023 Research Showcase. Her research, “Properties of Cementitious Materials with Reclaimed Cement,” evaluated the characteristics of cementitious materials mixed with varying percentages of reclaimed cement. Sunga and her fellow researchers examined each mixture’s initial setting time, heat of hydration and compressive strength and compared it against ordinary Portland cement. The purpose: to determine if adding reclaimed cement has any effect on the durability and use of cementitious materials. If there is little to no adverse effect, reclaimed cement may help reduce the need for new materials and can reduce the carbon bi-product of concrete. Dr. Shahriar Abubakri (Shah), Ms. Sunga’s supervisor at Rowan University, also joined us for the interview. 

Q. Could you tell us a little bit about your educational and research experience and how you got where you are now as a graduate research fellow at Rowan? 

A. I’m an international student from the Philippines. I graduated from the University of the Philippines – Los Banos in 2017 with a Bachelor of Science in Civil Engineering. After that, I worked in industry from 2018 to 2022. My former undergraduate professors, who were graduate students here [at Rowan], reached out to me asking if I was interested in pursuing graduate studies. I applied and began my Master’s in Civil Engineering in January 2023. 

Q. What interested you about researching the properties of reclaimed cement? Do you hope to continue research in pavement materiality? 

A. The environmental impact of reclaimed materials like cement is interesting to me. Cement production is a significant contributor to carbon emissions, so finding ways to reuse it is essential. Additionally, reclaimed cement presents unique challenges and opportunities in terms of material properties, durability, and performance. 

So, in a way, we’re helping produce less carbon emissions; that’s what interested me about this study. 

I’m currently working on a lot of different concrete projects. We’re hoping to develop more efficient construction approaches, but I also aim to contribute to the development of innovative techniques and solutions that will optimize reclaimed materials in construction projects. We also aspire to collaborate with industry partners and government organizations, so that we can implement these sustainable practices on a full-scale project in the future. 

Alyssa Sunga received the Best Poster Award for Student Research At the 25th Annual NJDOT Research Showcase in October 2023.

Q. Was there anything particularly noteworthy or surprising to you discovered from this research? 

A. Yes, there’s potential for reclaimed cement and enhancing the performance of unsustainable construction materials. We did not expect that we could use it as a replacement cement or as a supplementary cementitious material. Through various experiments, we found that using this reclaimed cement or incorporating it in cementitious mixtures resulted in comparable properties such as durability, strength, and workability. 

Q. Your research looked at cement paste and mortar specimens incorporated with up to 20% Reclaimed Cement and found no significant difference for the flow measurement and setting time. Should further research be done with higher percentages of reclaimed cement? Why did your research cap it at 20%? 

A. We’re planning to do further research on larger amounts of reclaimed cement. We just used 20% as a cap to get a general idea of the effect of partially replacing ordinary Portland cement with reclaimed cement. Now that our research with 20% is showing good results, we plan on doing tests with higher percentages in the future. 

Q. Your research found that cement paste specimens with up to 20% Reclaimed Cement (RC) saw a 4% reduction in compressive strength after 90 days. What does this mean for applicability (i.e. is 4% a significant reduction? does this make cement paste with 20% RC not suitable for pavement?) 

A. A 4% reduction may seem small, but it must still be taken into consideration. However, as long as the strength is within a recommended range, then it is suitable for pavement applications. 

Q. Is there a percentage of reclaimed cement that is most likely not suitable for pavement? 

A. Alyssa: My advisor would like to jump in to answer that. 

Shah: The acceptable percentage of reduction in concrete strength depends on the specific application and the assumptions made by the designer. For instance, practical standards like the American Concrete Institute (ACI 301.1.6.6) typically require that the average strength of three samples meets or exceeds the specified compressive strength. Additionally, each individual sample within this set should not fall below 500 psi of the designed strength. It’s important to note that concrete’s compressive strength can vary widely, ranging from 2500 psi to 5000 psi, and even higher in residential and commercial structures. Some applications may require strengths exceeding 10,000 psi. So, in cases where the required strength aligns with the design strength, even higher reductions may be acceptable. 

Q. Mortar specimens with 20% RC had a different result and surpassed the strength after 28 days. Why do you think this was a different result from cement paste specimens? What does this mean for applicability? 

A. This difference in result may be due to different factors, but mortar differs from cement paste due to the additional materials like sand. So, this can influence the hydration and the strength development, but we still need to do further research to understand the long-term performance and durability or the effect of adding different materials to the cementitious materials.  

We still must do further research to see the effects of adding different materials like sand and gravel to cement paste. If we’re going to use it in concrete, that’s another additional material like an aggregate. It’s just a matter of the specific materials. There are a lot of factors — like the temperature where you make your specimens. So, it’s always just trial and error. There’s no trend to it really. 

Q. Your poster suggests that incorporating up to 20% RC has some promising benefits including reducing carbon emissions. What are some of the other benefits?  

A. Incorporating the 20% RC will help mitigate supply shortages because we’re able to provide an alternative source of material instead of just using cement. It also promotes eco-friendly construction practices, contributing to sustainable transportation infrastructure, and research on reclaimed cement enables ongoing enhancements in material performance and construction methods. 

Q. You have mentioned throughout this interview where there’s a need for more research. Can you describe some specific things that you would really like to research about incorporating reclaimed cement into cementitious materials? 

A. The most important part of this research is determining what is the optimal mix proportions to use and then studying the effects on fresh properties and assessing the long-term durability like compressive strength, the tensile strength. These investigations are crucial for understanding the full potential of reclaimed cement in construction. Personally, I’m deeply interested in exploring these research areas further. 

Q. What kind of impact do you hope this research will have on material selection by transportation agencies? 

A. I hope this research convinces transportation agencies to use reclaimed cement in pavements. It’s sustainable, cost effective and performs well — aligning with transportation agencies’ goals and standards. This could lead to a greener and more resilient transportation infrastructure. 

Resources

Sunga, A., Abubakri, S., Lomboy, G., Mantawy, I. (2023). “Properties of Cementitious Materials with Reclaimed Cement”. Rowan University Center for Research & Education in Advanced Transportation Engineering Systems. Poster.

Yvette Sunga, A., Abubakri, S., Lomboy, G., & Mantawy, I.M. (2024). Properties of Cementitious Materials with Reclaimed Cement. Presented at IABSE Symposium: Construction’s Role for a World in Emergency, Manchester, United Kingdom, 10-14 April 2024, published in IABSE Symposium Manchester 2024, pp. 428-434. Retrieved at: https://structurae.net/en/literature/conference-paper/properties-of-cementitious-materials-with-reclaimed-cement

For more information about the 25th Annual NJDOT Research Showcase, and to see other award-winning posters, visit: Recap: 25th Annual NJDOT Research Showcase – NJDOT Technology Transfer (njdottechtransfer.net)

Testing Biometric Sensors for Use in Micromobility Safety

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Biometric sensors have long been used in cognitive psychology to measure the stress-level of individuals. These sensors can measure a variety of human behaviors that translate as stress: the movement of eyes, stress-induced sweat, and heart rate variability. Recently, this research strategy has moved beyond psychology and into disciplines like transportation planning, to provide an alternative approach to researching micromobility and stress.  

We spoke with Dr. Wenwen Zhang, associate professor at the Edward J. Bloustein School of Planning and Public Policy at Rutgers University, about her experience learning about and using biometrics for a micromobility study. Dr. Zhang’s research, “Rider-Centric Approach to Micromobility Safety” examines the stress levels of micromobility users as they transverse a varied path through an urban space.  

Q. How is your research funded? 

A. Funding comes from multiple sources. The first source is a seed grant from the Rutgers Research Council which supports an interdisciplinary pilot project. Through this grant, we purchased biometric sensors and hired students to conduct a literature review and develop a research design. We also processed the collected pilot data and paid for participation incentives under this funding. I presented preliminary findings from this study, Rider-Centric Approach to Micromobility Safety, at the 2023 NJDOT Research Showcase. At the time that I presented it, I had 24 samples. The presentation ended up inspiring several people who attended the Research Showcase to volunteer as participants—which increased the sample size to 30.

Our other source of funding came from an external grant from the C2Smart University Transportation Center (UTC) at NYU. We used this resource to support obtaining additional stress sensors, data analysis, cleaning, preprocessing, and modeling, as well as collecting more sample data for the E-scooter and bicycle experiments.

Q. How did you get interested in using biometrics sensors (e.g., eye tracking glasses, galvanic skin sensor, heart rate monitors) to study micromobility safety? How does this research differ from your past work? 

A. Before I used biometric sensors, most of my work used passive travel behavior data. For example, to determine the revealed preferences of mode and route choices and risk factors, we used travel trajectory or existing crash big data to develop statistical models. I have found that the entire process is very passive, especially since we only explore risk factors after traffic accidents. It’s surprising that in the research field today we know so little about how human beings actually navigate urban environments while using different travel modes and how it relates to perceived safety. I wanted to explore questions like what is their gaze behavior? How do they feel while they travel using different modes? How do they feel traveling on roads with different design features and how is that going to influence their travel satisfaction or experience overall? 

Dr. Robert Noland, Distinguished Professor at the Rutgers Bloustein School, suggested I investigate the use of biometrics in planning studies. As I dug more into the literature, I realized that biometrics in transportation is a very fascinating topic that I wanted to get into. Once I did experiments in the field, I realized that I really enjoyed talking with different people about how they perceive the built environment while they travel. Biometrics provide richer data compared with revealed preference data that I used to work with.

Q. In your research, you noticed that some corridors were more stress-inducing (according to biometric sensors) than expected, despite properly designed safety infrastructure. How do you think this discovery may affect how planners and engineers look at urban road design and micromobility safety? 

 A. This study collected one-time cross-sectional data. We asked people to walk around an area and tell us whether they feel stressed or not. If they are feeling stress, even in the presence of a safety improvement, it does not necessarily mean that the implemented safety design is not working. For example, in New Brunswick, we observed that a lot of people found it stress-inducing to cross Livingston Avenue, although it has been the subject of a road diet and has several pedestrian safety features incorporated into the new design. While outside our scope of research, one way to understand the impact of the safety infrastructure would be to conduct a “before” and “after” study. This leaves an opportunity for more research, to see how effective the pedestrian-only infrastructure is in reducing stress level. Potentially, it can provide evidence to support pedestrian-only design. Biometric sensors used in a “before and after” study can help us to answer which infrastructure is more preferred. 

Q. You are in the process of collecting data for cyclists and e-scooters using the same method, what are your principal objectives in addressing this segment? Do you expect the results to be different?

Dr. Zhang conducted one pilot e-scooter experiment at Asbury Park, NJ in 2022 to test out the devices and examine how to set up research experiments. She equipped the e-scooter rider, Dr. Hannah Younes, post-doc researcher at the Rutgers Bloustein School, with an eye tracking glass, a GSR sensor on the hand, and a 360-degree camera on top of the helmet.

A. Yes, absolutely, different travel modes will likely alter a person’s expectation for a safe travel environment. For example, we noticed a big difference in the enjoyment of pedestrians and e-scooters on the same path through a park. We had thought that the e-scooter users would enjoy the ride as the pedestrians had, however, the pavement was too rough for the small wheels of the e-scooters. Although the park was walking-friendly, it was not friendly for e-scooters. This shows that each of these micromobility modes needs different kinds of support to feel safe and comfortable.

Q. What are the limitations to this study? Do you have plans for future research to address this? How would you like to expand your research in this topic?

A. Each of the biometric sensors has limitations. For example, eye trackers face some difficulty when identifying the pupils of a participant in direct sunlight. As a result, the eye tracker renders a low eye tracking rate. Eye trackers also work better with darker eyes as the eye movements are more readily recognized. The eye trackers, kept on glasses, also restrict individuals who wear glasses from participating. The unfortunate result of this is that it often excludes a lot of senior people from the experiment. This issue may be alleviated as we are obtaining additional funding to obtain prescription lenses for eye trackers.

GSR sensors use low voltage on skin to measure skin conductivity, which may interfere with electric health devices. This limits individuals from participating if they have an electric health device like a pacemaker on or in their body. We purposefully excluded this population from participating to align with IRB (Institutional Review Board) protocol and to mitigate any risks.

Another limitation of the study is that we must collect sample data one by one, which is a time-consuming process. We can only collect a very small sample compared to a traditional statistical model kind of study, which may have access to thousands of records in the sample. From our literature review, biometrics sensor studies typically involve 20 to 30 participants, but for each participant we have a very rich dataset. For each participating volunteer, we end up with over one gigabyte of data. The limited number of participants may make it harder to generalize results to the entire population, and people may question the results applicability. In some ways this data is similar to the results of qualitative studies, where we have richer information but small sample size, rendering some generalizability issues. 

Feelings of safety were measured using the traditional self-report survey as well as biometric trackers like Heart Rate Trackers, Eye trackers and GSR (pictured above).

Q. What challenges have you found in working with biometrics sensors, or in the interpretation of output measures?

A. The eye tracker and heart rate measures are reliable, but some biometrics have posed challenges. The GSR (galvanic skin response sensor), which tests your sweat level, is very sensitive to humidity and time of the day. The sensor also picks up on sweat resulting from physical exertion, making it difficult to distinguish between stress-induced sweat and physical sweat.

Interpretation of output measures for this metric requires data cleaning and processing to eliminate the effect of sweating from physical exertion. We try to decompose the data to separate the emotional peak from the sweating caused by physical activity using various algorithms. We are still underway testing out different algorithms to clean up the data. So far, we have found that GSR data are very real-time in nature and a good indicator for stress level but are very noisy data and requires some manual processing. This means we spend a lot of time preprocessing the collected data before conducting data analysis. 

Q. How do you expect this research to inform transportation agencies in New Jersey and elsewhere?

A. This type of research captures such rich data on travel behavior itself. Most of the literature using biometrics has been focused on driving, so this research expands the perspective. Here we’re focusing on slow mobility, like active travel and micromobility. Individuals who participate in slow mobility are more vulnerable road users, and we want to see how they behave in different travel environments. This can help agencies gain more insights into how to design safety infrastructure. Beyond that I can also envision the technology being used to evaluate whether certain improvements or infrastructure designs help to improve travel satisfaction or improve people’s experience at the same location by doing “before and after” studies. This type of study also allows you to measure and quantify the effect of the improvement. 

The use of biometric sensors in the field can also be used to foster meaningful public engagement processes to show the lived experience of different people in a neighborhood or traveling through a different corridor, which can be very powerful.

Q. Do you feel the research methods are at a stage where they are “ripe” for use on other demonstration projects, planning or project development studies?

A. After one year of experimentation, our project team can readily work with biometrics. We have a good understanding of sensor limitations and how to set up the sensors to correctly reduce noise as much as possible. Our experience has also helped determine what kind of metrics can be extracted successfully and reliably through the sensors.  

The most useful case for those sensors is to evaluate before and after, so that we can quantify how much people appreciate those implementations in a more accurate way. Beyond that, the sensors can also be effective infrastructure assessment tools. For example, imagine that you ask people to wear biometric sensors and do a bicycle infrastructure evaluation; the agencies can get more realistic and rich data compared with a more traditional survey approach. This rich data can help determine the most effective improvement. It ends up being more inclusive that way.

The tools can be very useful for fostering community engagement with vulnerable populations. For example, if agencies want to improve the accessibility for wheelchair users, they can ask individuals in wheelchairs to wear the sensors and move about an area. Recording and reviewing how they experience a journey is more powerful compared with just asking individuals with needs about their travel patterns. It’s going to be a more straightforward way to show the world how we can make the streets more inclusive for those vulnerable populations. 

Q. Do you think local governments and non-governmental organizations could make use of biometrics sensors as a strategy to promote community engagement and outreach to local communities, or to address specific community safety or livability issues?  Would it be cost-prohibitive to employ such tools for such community-based planning issues at this time?  

A.  From my point of view, the most effective way would be for the agencies to identify where there are needs and promising projects and then work with skilled researchers or practitioners who have these sensors already and have begun to climb the learning curve in the use of sensors and interpretation — for example, they could work with us. They would need to pay for the researchers’ time and participation incentives, or if they were to collaborate with a UTC (University Transportation Center) to conduct such research collaboratively.  

The sensors are not the most expensive part of the study. The most expensive item is the researcher’s time to collect and analyze the data. The data are very complicated to analyze in the first place because it’s a large amount of data with noises. The researchers need to put in a lot of time to get it to the state where you can extract the relevant variables out and start to interpret them.

Q. How would you characterize the “state-of-training” in using biometrics for students or early career or mid-career professionals in transportation?    

A. The biometric sensor itself is not very new, but new to the transportation field, especially for slow modes. It has been widely used in cognitive psychology, where there are classes to interpret those as well. Generally, I don’t think the current transportation and urban planning curriculum for students includes enough classes to cover those sensors. We probably need to teach not only biometric sensors, but urban sensing in general. 

In an ideal course, students could get their hands dirty by putting those sensors in the field and then once the data are collected, they can learn how to preprocess and analyze the data. It would have to be a one-year kind of curriculum design to get people involved and ready for it. Of course, instruction on the use of sensors will differ by topic. For example, if you are working in the air quality field, then there are many different air quality sensors and each of them come with different data formats and require different experiment design and analytic skills.

Regarding the mid-career transportation professional, at this moment I believe the research is more in the academic field and focusing on testing and evaluation. I wouldn’t suggest that the research is so ripe that a mid-career transportation or urban planner professional should need to invest their time in learning how to use biosensors unless they have a research project that may benefit substantially from using the sensors.  

Resources

To learn more about the use of biometrics in the field of active transportation, see:

Ryerson, M., Long, C., Fichman, M., Davidson, J.H., Scudder, K.N., Kim, M., Katti, R., Poon, G. & Harris, M., (2021). Evaluating Cyclist Biometrics to Develop Urban Transportation Safety Metrics. Accident Analysis & Prevention, Volume 159, 2021. Retrieved from https://www.sciencedirect.com/science/article/pii/S0001457521003183?via%3Dihub

Fitch, D.T., Sharpnack, J. & Handy, S. (2020). Psychological Stress of Bicycling with Traffic: Examining Heart Rate Variability of Bicyclists in Natural Urban Environments. Transportation Research Part F: Traffic Psychology and Behavior, Volume 70, 2020, Pages 81-97. Retrieved from https://www.sciencedirect.com/science/article/pii/S1369847819304073?via%3Dihub.

To read more on Dr. Zhang’s work, see:

Zhang, W. (2023). Rider-centric Approach to Micromobility Safety. 25th Annual NJDOT Research Showcase. Presentation. Retrieved from https://www.njdottechtransfer.net/wp-content/uploads/2023/11/Zhang-Safety-2nd-Presentation.pdf.

Zhang. W. 25th Annual NJDOT Research Showcase. Recording starts at: 59:00. Retrieved from https://youtu.be/D_rQP-Dv8gU

Zhang, W., Buehler, R., Broaddus, A. & Sweeney, T. (2021). What Type of Infrastructures do E-scooter Riders Prefer? A Route Choice Model. Transportation Research Part D: Transport and Environment, Volume 94, 2021. Retrieved from https://www.sciencedirect.com/science/article/pii/S1361920921000651.

For more information about the use of biometrics in the broader transportation field, see NYU’s C2SMART’s research project on Work Zone Safety:

Exploring the Future of Environmental Product Declarations at NJDOT: Q&A Interview with NJDOT’s Project Lead

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Under the FHWA’s Climate Challenge, state DOTs and local agencies receive training and work with various stakeholders including those from industry and academia to implement projects that quantify the environmental impacts of pavements using Life Cycle Assessment (LCA) and Environmental Product Declarations (EPDs). EPDs provide an in-depth look at the use effects and environmental impacts of materials, processes, and mixtures. With a general goal to reduce carbon emissions, DOTs are moving towards the use of EPDs for selecting pavement uses and processes.

We spoke with Nusrat Morshed, Project Engineer in the Pavement Design & Technology Unit at NJDOT, about two FHWA project grants funded under the Climate Challenge initiative that she supervises. Both projects focus on the potential use of EPDs and LCA in New Jersey and will allow for NJDOT to develop a strong baseline understanding of EPD use.

FHWA – Funded Climate Challenge Projects

Q. Can you tell us about two FHWA-funded Climate Challenge projects listed for New Jersey. How is NJDOT currently involved in these FHWA funded projects? What are tasks for these projects?

A. NJDOT applied for this research project funding in early 2023 after the advertisement was released. I had spoken with representatives from Rowan University and Rutgers University to gauge their interest in this research, and both were on board. EPDs is a very new concept and term within the transportation field. This made it challenging to determine what the project scope should be for our grant applications. We received funding from FHWA immediately, but there were some technical issues in the allocation of state and federal funding shares that we needed to sort out before we could proceed. Both research teams officially began work in September and October of 2023 and they will have until the end of 2024 to carry out the work.

The research team for Project 1, Utilization of EPDs and LCAs to Promote Sustainability in NJ’s Pavements, is led by Dr. Yusuf Mehta from Rowan University and they are teamed with the research sub-consultant, Advanced Infrastructure Design (AID). The objective of this project is to utilize EPDs and LCAs to promote consideration of sustainability in maintaining NJDOT’s pavement infrastructure. The tasks within this project scope include: conducting a literature review, defining the goals and scope of the comparative LCA analysis, data collection, and analysis of results and interpretation.

The research team for Project 2, Improve Sustainability of Asphalt Pavement Overlay in NJ, is led by Dr. Hao Wang from Rutgers University. The research project objective is to improve the sustainability of asphalt pavement overlay in New Jersey. The project’s basic tasks include: documenting experiences and lessons of using FHWA’s LCA PAVE tool based on analysis of pavement overlay project in New Jersey DOT, evaluating quantification methods for calculating carbon emissions at the use phase of pavement, providing recommendations for use of LCA in decision making of pavement overlays, and preparing a final report and presentation.

Example EPD summary, retrieved from USDOT FHWA Tech Brief: Building Blocks of Life-Cycle Thinking

I am the key point person for both projects.

Q. What is the status of these FHWA funded projects? What resources have been helpful so far?

A. Both projects are underway now but still in the early stages. I received a status report from Project 1 about a month ago and expect a status report from Project 2 before March. For both projects, the focus has been to complete a literature review. One resource that was particularly helpful was the National Asphalt Pavement Associations (NAPA) website, as they have a lot of information on EPDs — 15 EPDs thus far have been identified — which are NJDOT specifications. We have also reached and had a meeting with the Port Authority of New York and New Jersey (PANYNJ) to get information on their own EPD process.

Q. The FHWA Climate Challenge program seems like it has established an approach to promote knowledge sharing and fostering a community of practice. Can you tell us about it?
A. Every quarter, FHWA conducts a climate challenge webinar, and on this webinar there is usually a featured presentation from an expert and then brief update presentations from climate challenge project teams. These project teams extend beyond New Jersey, so other states can hear how NJDOT is doing with these projects and we can learn from our peers in other states.

Previously our updates have been limited to 2 or 3 slides, however, later this spring I will have two reports to base our presentation upon, which will be more comprehensive and reflective of NJDOT’s progress.

Attendees at a Climate Challenge Training session. source: FHWA

The quarterly webinars have been helpful and instructive. EPDs and sustainable resiliency are also very hot topics and several other resources are emerging that we can reference. For example, there was an entire session on EPDs at the Transportation Research Board’s Annual Meeting. Published literature has also been very helpful.

As a part of the project grants, FHWA is providing EPD-specific trainings. Both research teams and I have brainstormed about trainings our teams require. I have coordinated with FHWA as a Climate Challenge member and explained our training needs for accomplishing these two projects. FHWA and I drafted an agenda based on these research needs and we have scheduled a day and a half in-person training for March 2024. I requested that both of my teams submit their findings, as a status report before that training. So it also will be our official first status meeting for both project teams.

As a Project Engineer overseeing these projects, I am not able to work directly with the research, but I provide guidance to the universities and have been the communication bridge between them and FHWA. The training is hosted by FHWA and conducted by FHWA and a third-party organization that specializes in EPDs. These trainings are hosted throughout the U.S. To make this happen, FHWA provided us with their schedule, and we negotiated a time for them to do the training in March 2024.

Q. Who was in attendance for this training?

The training was done on March 12-13, 2024 at NJDOT. This training was focused on team members from both projects. There were representatives from the NJDOT Bureau of Materials, NJDOT Bureau of Statewide Strategies and NJDOT Division of Environmental Resources who participated.

Q. How has this funding assisted with NJDOT’s Every Day Counts (EDC) EPDs related goal?

Unless a NJ STIC Incentive Grant is awarded, FHWA does not provide any funding directly for advancing the EDC-7 innovation, but instead supports the deployment goals through the mobilization of FHWA resource specialists or subject matter experts who are farther along with innovation’s deployment. Luckily, the research of EPDs is a goal within EDC-7, so both of the funded Climate Challenge projects are indirectly supporting that EDC-7 goal.

Q. Have any pilot programs begun?

As we are still in the research stage for EPD use, we have not created any pilot programs yet.

Environmental Product Declarations in the Future

Q. Can you describe the status and implementation goal for NJDOT’s EDC-7 goal for advancing EPDs in New Jersey?

NJDOT’s EDC-7 goal for advancing EPDs in New Jersey is still in the preliminary stages of information gathering. Both of these climate challenge projects will assist with building up a robust set of literature that is necessary for next steps. Our goal is to get ideas for future recommendations. As of now, I would say we need to identify a few plants or suppliers and get some real-time data for different types of considerations based on research needs. Then we need to identify which way we can achieve EPD targets like lowering carbon emissions.

The stages of Pavement’s life cycle. Retrieved from USDOT FHWA Sustainable Pavements Program.

Q. What challenges, if any, has NJDOT faced while working to incorporate EPDs into pavement considerations?

EPD is based on many stages, which require their own literature review. For example, a product category rule, or a set of rules for measuring life-cycle analysis must be developed first. EPDs have different stages that all must be measured — specifically, the production stage, transportation stage and construction stage, or as they are called the A1, A2, A3. Achieving the goal of reduction in carbon emissions through EPDs requires a lot of research and literature review, and it will not be easy to get all the needed information, even when speaking with experts. Starting from scratch, the ability to quantify an EPD could take at least two years. So, it’s not that you will be getting something very quickly. We are just exploring now what is out there and how we can think about something in terms of New Jersey’s pavement mixes.

Q. How does NJDOT use or reference the published EPDs in New Jersey as reported by the National Asphalt Pavement Association’s Emerald Eco-Label tool?

We have looked at the National Asphalt Pavement Association (NAPA) website and reviewed their own PAVERS tool. It has been helpful to see how they do life-cycle analysis. They have their own LCA tool and we use the FHWA LCA tool — so there will most likely be differences. The FHWA LCA tool is expected to be updated soon.

Q. Do you foresee NJDOT having an embodied carbon clause added to NJDOT contract specifications? Will contractors be expected to submit an asphalt mix that provides EPDs to be considered for future contracts?

LCA PAVE Tool assists with analysis and quantification of the environmental impacts of existing products or processes. Retrieved from USDOT FHWA

Yes, definitely, we can dream, but it will take time. We need to identify and set the product category rule. More research is needed, maybe there will be future training opportunities on this topic from FHWA.

Q. Where is the biggest research gap when it comes to the incorporation and use of EPDs? Is it research on the pavement itself, or life cycle analysis, or something else?

EPD is not a single term, but a combination of a lot of things. In the process of determining an EPD for one pavement treatment, you must consider the process of installation, the type of pavement or asphalt mix, the binder and aggregate within the mix, etc. Because each of these processes require their own considerations, we must make the decision on what process and pavement, or asphalt mix should be evaluated first. We can then use our results to determine where the use of EPDs would be most helpful, or which process should be studied next. In other words, we cannot do everything at once, but rather start very specifically and focused, and then move out.

The five steps of developing Environmental Product Declarations (EPD). Retrieved from Tech Brief: Building Blocks of Life Cycle Thinking

 Q. Has NJDOT had an opportunity to use or test the FHWA LCA Pave Tool? If so, how does it use the tool?

I have used that tool before, but I just use it as a general gauge as I don’t have any real-time data currently. I will need training in the future on how to efficiently use the tool based on actual data. I also think this tool will be helpful in the future for determining if our results are realistic. Our research team members are using this tool.

 Q. How are you feeling about this initiative?

As a state government employee, I see this initiative as an effort that will help NJDOT be aligned with NJ’s clean energy policies. EPDs are a new topic for us, and everyone is very interested in learning more about it, including me. The funding opportunity that FHWA provided allows DOTs throughout the U.S. to explore this new topic and determine its applicability in the future of pavement and asphalt design.

Resources

FHWA Climate Challenge – Quantifying Emissions of Sustainable Pavements. FHWA webpage. Retrieved at https://www.fhwa.dot.gov/infrastructure/climatechallenge/projects/index.cfm

LCA Pave Tool. FHWA webpage. Retrieved at https://www.fhwa.dot.gov/pavement/lcatool/

Emerald Eco-Label. Webpage. Retrieved at https://asphaltepd.org/published?state=NJ

What is Environmental Product Declaration (EPD) for Sustainable Project Delivery? Webpage. Retrieved at: https://www.njdottechtransfer.net/epds-for-sustainable-project-delivery/

Life Cycle Assessment: Part I Fundamentals. Webinar, FHWA Sustainable Pavements Webinar Series. Retrieved at: https://youtu.be/uaJ8wGMAPD0?si=oBHnBSN2K1589JEa

An Introduction to Life Cycle Assessment: Part II – EPDs and PCRs, FHWA Sustainable Pavements Webinar Series. Retrieved at: https://www.youtube.com/watch?v=Y4OqVR6U2Us

Sustainable Pavements Program. FHWA Webpage. Retrieved at https://www.fhwa.dot.gov/pavement/sustainability/

Sustainability Analysis: Environmental. Life Cycle Assessment (LCA). FHWA Webpage. Retrieved at: https://www.fhwa.dot.gov/pavement/sustainability/environmental/

Meijer, J., Harvey, J., Butt, A., Kim, C., Ram, P., Smith, K., & Saboori, A. (2021). LCA Pave: A Tool to Assess Environmental Impacts of Pavement Material and Design Decisions-Underlying Methodology and Assumptions (No. FHWA-HIF-22-033). United States. Federal Highway Administration. Retrieved at: https://www.fhwa.dot.gov/pavement/lcatool/LCA_Pave_Tool_Methodology.pdf

Milleer, Lianna; Ciaviola, Benjamiin and Mukherjee, Amlan. (February 2024). EPD Benchmark for Asphalt Mixtures, SIP-108. Prepared for National Asphalt Pavement Association by WAP Sustainability. Retrieved at: https://www.asphaltpavement.org/uploads/documents/EPD_Program/NAPA-SIP108-EPDBenchmarkForAsphaltMixtures-Feb2024.pdf’

STIC Incentive Program Funds are Available!

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The Federal Highway Administration (FHWA) offers STIC Incentive Funding, as well as technical assistance, to support the standardization and advancement of innovative practices. The NJ STIC receives $125,000 each year and state and local public agencies in transportation are eligible to apply.

To be eligible, a project or activity must have a statewide impact in fostering a culture for innovation or in making an innovation a standard practice, and must align with FHWA’s Technology Innovation Deployment Program goals.  The NJ STIC will consider projects and activities that advance innovations such as the Every Day Counts (EDC) innovations that are being promoted by FHWA.  

Proposed STIC project ideas are prioritized by the NJ STIC for each federal fiscal year. Selected projects are then submitted to the Federal Highway Administration (FHWA) for approval. The request submittal does not guarantee funding nor award of funding.

The NJDOT Bureau of Research, Innovation and Information Transfer is ready to answer your questions and assist applicants. For more information on eligibility, proposal requirements, past funded projects, and more, please visit: the New Jersey STIC Incentive Fund Requests webpage.

NJDOT Lunch and Learn: An Inside Look at the Research Library and its Digitization Project

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In the 1940s, the State Highway Department (predecessor to the New Jersey Department of Transportation) created its first departmental library for transportation information. For the past 80 years, this depository of relevant transportation articles and materials has grown. Today NJDOT’s research library is a part of the Bureau of Research, Innovation & Information Transfer. The library offers employees several research and career development resources and holds a collection of documents of notable histories of transportation in New Jersey.

As a part of the NJDOT’s Lunch and Learn series, on February 22, 2024, Eric Schwarz, NJDOT’s research librarian, gave NJDOT employees an overview of the resources available through the NJDOT Research Library and directed a portion of his talk to “Discoveries in the First Year of the NJDOT’s Digitization Project.” The digitization project is an effort to make past documents, films, and other materials from the NJDOT archive, accessible online. Eric has been instrumental to the digitization project, leveraging resources of the multi-state Transportation Research and Connectivity Pooled Fund Study Digitization Project [TPF-5(442)].

The Lunch and Learn presentation gave NJDOT employees an overview of the NJDOT Research Library and highlighted several digitally archived historical materials and “lessons learned” during the first year of NJDOT’s digitization project.

Materials range from historic newspaper articles of The Highway to documentary clips of past infrastructure projects and initiatives. Materials have been selected, catalogued, indexed, processed, and preserved by Eric. The digitized materials are now accessible on the Internet Archive’s page for the NJDOT Research Library and contribute to the overall story of transportation in New Jersey.

Notably, the digitization efforts led to uncovering the names of several NJDOT employees who died while working for the department and its predecessor agencies. Five of these individuals were recognized at the Annual Remembrance Ceremony held in September 2023 with name plaques added to a Memorial Wall maintained by NJDOT at Headquarters. As noted during the Lunch and Learn presentation, additional documentary evidence has been found of persons who lost their lives while on duty as the digitization project has proceeded in recent months.

Eric’s presentation conveyed how the digitization project contains a well-spring of information that may prove of interest to historians and other researchers. Digitized materials like old photographs, maps and videos show the makeup of the highway commission in 1922, the number of miles in the State Highway System in 1925, and the number of women who have served as transportation commissioner. The digitized materials reveal several ways that NJDOT has contributed to safety innovations in transportation, including the implementation of cloverleafs, breakaway signs, center barriers, and the piloting and expansion of Emergency/Safety Service Patrol operations. This and other information about the state’s transportation history was made engaging and interactive through mini-pop quizzes.

Eric displayed the research poster about the Digitization Project presented at the Transportation Research Board Annual Conference held in Washington DC in January of 2024 at the Lunch and Learn event.

In addition to describing the digitization process and lessons learned participating in the pooled funded study, Eric gave an overview of the NJDOT Research Library, including its various services and available resources.

Eric noted reference and research services that can be accessed through the NJDOT Research Library. Employees, as well as other transportation professionals, may access various online resources and databases through the research library. Online databases and other sources include:

  • TRID (Transportation Research Board) — A collection of worldwide transportation research
  • Bureau of Transportation Statistics — Statistical information useful to transportation professionals
  • ROSA-P — the National Transportation Library’s Repository and Open Science Access Portal
  • ASTM Compass — Specialty documents from ASTM, AASHTO, American Welding Society
  • AASHTO (American Association of State Highway and Transportation Officials) — Standards and Publications

The research library also provides professional development tools like exam preparation books that can be lent out for several weeks. These books will help professionals prepare for a range of Civil Service and Professional Exams.

As state employees, NJDOT employees can apply for a State Library card, which must be renewed every two years. This card allows individuals to borrow print materials from the NJDOT research library, as well as the New Jersey State Library

Eric noted that links to several online resources and other information about the NJDOT Research Library can be found on the NJDOT Research Library page including links to the NJ State Library which contains additional transportation-related resources.

In addition to the recording, the Lunch and Learn presentation slides can be found here.

Resources

Notable Digitized Materials

Accelerated Innovation Deployment (AID) Demonstration Funding Opportunity Available for FY2024

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AID Demonstration Program is active again! The Accelerated Innovation Deployment (AID) Demonstration provides incentive funds to eligible entities to accelerate the implementation and adoption of innovation in highway transportation. FHWA has awarded 127 AID Demonstration grants at more than $95.7 million dollars since its launch in 2014. These funds can be used in any phase of a highway transportation project between project planning and project delivery, including planning, finance, operation, structures, materials, pavements, environment, and construction.

The 2023-2026 AID Demonstration Program will make available up to $10 million in grants in Fiscal Year (FY) 2023 and $12.5 million in FYs 2024 through 2026. One change in the new Notice of Funding Opportunity (NOFO 693JJ324NF-AIDDP) for AID Demo is the requirement for potential applications to submit Notices of Intent. While the deadline has passed for the FY 2023 solicitation period, the FY 2024 solicitation period will open on www.grants.gov on February 27, 2024, with the NOI deadline of April 16, 2024, and closing date of May 28, 2024.

The FHWA EDC-7 Team has put together this list of suggested project ideas that can help deploy the EDC innovations either via STIC Incentive Fund Grant projects or AID Demonstration applications.

Q&A: NEVI Deployment and GHG Reduction Initiatives

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New Jersey Department of Transportation, alongside other state and regional agencies, has embarked on ambitious initiatives to revolutionize its transportation fueling infrastructure through the National Electric Vehicle Infrastructure (NEVI) Deployment and through pursuit of Greenhouse Gas (GHG) emissions reduction target goals. These initiatives are rooted in the state’s commitment to the 2019 New Jersey Energy Master Plan, the New Jersey Global Warming Response 80x50Act, the 2022 Inflation Reduction Act, and the 2021 Federal Infrastructure Investment and Jobs Act, among other state and federal initiatives, to encourage electric vehicle (EV) adoption and cut transportation-related emissions, marking critical steps towards New Jersey’s climate goals.

We recently spoke with Megan Fackler, Director of Statewide Planning and Sudhir Joshi, Manager of Statewide Strategies from the New Jersey Department of Transportation (NJDOT) to learn more about NJDOT’s ongoing activities for advancing these two initiatives. Their involvement in the planning for NEVI Deployment and the Every Day Counts (EDC-7) innovation, “Integrating GHG Assessment and Reduction Targets in Transportation Planning,”  place them at the heart of the NJDOT’s carbon reduction efforts.  This interview has been condensed and edited for clarity.

NEVI Deployment Challenges and Strategies

Q: What has NJDOT been doing to advance NEVI Deployment since Plan acceptance in 2023?

A: The National Electric Vehicle Program is a program from the Joint Office of Energy and Transportation, delegated to the Federal Highway Administration. NJDOT is going to deliver this program in New Jersey.

At NJDOT, our approach has focused significantly on federally mandated stakeholder engagement on a statewide basis. Our traditional outreach, utilizing project-specific and countywide approaches, was adapted to address the breadth of the state-led, statewide initiative. This entailed actively involving various community groups, small business leaders, partner agencies, utility providers and other private industries. We have utilized various channels such as public information centers, social media, and weekly emails.

Our team coordinated with every level of our Department to prepare for our larger meetings with external stakeholders. We have had a lot of discussions internally with our subject matter experts, who have helped develop our approach to contract procurement that incorporates the comprehensive criteria outlined in the NEVI guidelines and ensures contractors are complying with state guidelines as well.

We put on a pre-bid conference on October 17, 2023 that explained the range of requirements that the awarded contractor must fulfill.  We have sought to ensure contractors understood that they would need to comply with federal and state standards. For example, chargers must be accessible within 1 mile of New Jersey’s Alternative Fuel Corridors and provide a convenient, reliable charging experience for all users.

In developing our approach, NJDOT has decided to assign a single contractor to manage an EV charging site’s full range of compliance, with priority given to DC fast chargers. A DC Fast Charge operates on a voltage of 208 to 480 volts three phase alternating current — this is not a circuit you would likely have in your home. In 20 to 30 minutes of time, the DC fast charge should deliver 80 percent of a full charge of the vehicle’s battery.

At each of the 19 EV charger stations development zones along New Jersey’s Alternative Fuel Corridors, a 4-charger station will be provided, with each of the EV chargers capable of providing simultaneous charging at 150 kilowatts. Each charger will be equipped with a Combined Charging System and a North American Charging Standard, also known as the Tesla, port.

Contractors were informed about site selection responsibilities, environmental review documentation, and the necessity for agreements with site hosts and utility providers. The contractor will choose the locations of the 19 proposed sites and will provide one comprehensive environmental review applicable to all sites. The Department also stressed the importance of planning, design, and maintenance to ensure a high-quality user experience, requiring contractors to have the proper reporting mechanisms in place to monitor satisfaction and usage. There were additional discussions on revenue opportunities, and the inclusion of disadvantaged business enterprises.

NJ Alternative Fuel Corridors (AFCs) and Direct Current Fast Charger Development Zones were shared at NJDOT’s Virtual Public Information Center sessions.

In our pre-bid meetings, we have emphasized several other requirements that an award must encompass, such as the ensuring that traditionally underserved communities are included.  The awarded contractor will need to submit: a Justice40 Plan detailing benefits and impacts on overburdened communities; a workforce development plan geared to this new technology including recruiting efforts toward underrepresented groups; and other documentation that commits to monitoring and upgrading chargers over a period of 5 years of required maintenance.

Additionally, contractors must hire pre-qualified personnel such as a NJ-licensed Professional Engineer who will design the station, before an entity installs the actual chargers. Electricians must be pre-certified by the Electric Vehicle Infrastructure Training Program (EVITP) or complete an apprentice program approved by US Department of Labor.

Following the planning and installation of DC fast chargers, contractors are also required to operate and maintain the station. For example, contractors are required to ensure that their charging stations remain operational and accessible for at least 97 percent of the time over the course of each year. These standards emphasize that trained personnel are crucial to the success of the program.

We are planning to issue and advertise an RFP in 2024 and begin issuing the first awards. Projects on the NJ Turnpike and Garden State Parkway will be handled separately from this Alternative Fuels Corridor procurement.

Q: What are some of the challenges in achieving the goals of the NEVI Deployment Plan?

A: We must ensure that we align our internal schedules to federal timelines, while also ensuring compliance with the program’s equity and environmental goals and requirements. Other challenges include coordinating with utility providers in a timely manner and including them in pre-bid discussions with contractors. In all of this, our team is also prioritizing stakeholder feedback and accounting for their feedback in our analysis.

Electric vehicle chargers by type and level.  NJDOT will focus on first deploying DC Fast Chargers. Source: Union County, NJ.

It is important to recognize that FHWA did not define for NJDOT how best to achieve the NEVI plan’s deployment goals. For example, it was unclear when we first started thinking about the project whether it made more sense to hire a single contractor to oversee the project – soup to nuts, or to break the project into contracts for different parts. The Department worked with the FHWA to develop a specific approach that supports EV charger implementation in New Jersey.

Q: What types of in-house technical expertise, knowledge, skills, and/or abilities will NJDOT need to have to aid in successful implementation of EV and larger carbon reduction goals?

A: NJDOT’s in-house capabilities are focused on two main areas of expertise: contracting and environmental compliance. First, the Division of Project Management, in conjunction with our Division of Procurement, specializes in various construction and non-construction contract types. Their policies and procedures guide NJDOT staff to ensure that all contractual aspects are timely managed.

Second, the Environmental Division plays a crucial role in addressing environmental compliance and specific site needs. These internal resources, combined with external consultants, form the backbone of NJDOT’s strategy for advancing its carbon reduction goals, and NEVI in particular.

In addition, NJDOT anticipates and prepares for future aspects of NEVI, such as inspection and maintenance requirements of EV charging stations. It is possible that inspection tasks may be outsourced as a result.

NEVI Stakeholder Engagement

Q: How are you facilitating community engagement and awareness about the NEVI Program? What are the major challenges in engaging with local government and other affected stakeholders.

A: NJDOT has implemented a few initiatives. Our outreach was mainly a success with a few key challenges. We initially encountered some skepticism from stakeholders in terms of the locations for charger sites and EVs in general. We have worked hard to maintain a robust community engagement process statewide that satisfied federally mandated outreach guidelines. This includes our Virtual Public Information Center (VPIC) sessions and online resources, which generated thousands of views and hundreds of comments.

With a focus on equity, we identified broad stakeholders from previous working groups and through our legislative partners. The Department leveraged our partnerships to help raise awareness of our engagement sessions. The goal of the VPIC sessions was to reach representatives of diverse groups, provide NEVI Program information relevant to New Jersey, and allow for individuals to comment back to the Department in ways convenient for them.

Workforce Readiness/Equity and NEVI Deployment

Q: What steps is NJDOT taking to ensure workforce readiness and environmental justice for the NEVI Program?

A: Our role principally involves conveying expectations and setting specifications for contractors. These specifications, among others, includes abiding by EVITP requirements, or an approved apprenticeship program for hiring skilled staff familiar with EV technologies. The contractor will be responsible for training and ensuring that the workforce is equipped with the necessary skills, particularly for deploying DC Fast chargers. These requirements also apply to the subcontracting process as well, where partnering with Disadvantaged Business Enterprises (DBEs) is highly encouraged.

FHWA’s framework to ensure equitable recruitment from underserved groups.

In recent years, the Department has been making a huge shift toward workforce development, such as with our investment in the Bordentown Training Center. This is an ever-evolving topic of conversation for us at NJDOT on how we can carry out our “commitment to communities” – whether it is speaking at the community colleges or opening the doors of training facilities for local municipalities. While there is nothing concrete at this time, I definitely could see EV charging maintenance integrated into the training center in the future should such support from NJDOT be needed.

We also have strategies to monitor progress towards our environmental justice goals, such as leveraging various tools and mapping technologies and producing the Community Engagement Outcomes Report (FHWA Approval of NJ NEVI Plan, 2023). The contractor’s role will be pivotal in this regard, as they will be tasked with effectuating Justice 40 initiatives and addressing environmental justice considerations in their operations.

EDC-7 Innovation and Greenhouse Gas Assessment

Q: How does NJDOT’s Carbon Reduction Strategy align with the NEVI Deployment Plan, and what steps are being taken to work with MPOs on this initiative?

A: NJDOT is taking specific steps that align with the goals of the NEVI Deployment Plan, including expanding the EV infrastructure at interstates, and then branching into more local areas. NJDOT’s Carbon Reduction Strategy directly supports the goals of reducing emissions established by Governor Murphy and President Biden. The strategy aims to meet the Governor’s mandate of 80 percent reductions by 2050, and President Biden’s goal [of carbon neutrality by 2035], through strategies aligned with the NEVI Deployment Plan.

NJDOT is working alongside its MPOs and NJ Transit partners to set and meet the FHWA’s recently issued rules on greenhouse gas emission targets. This includes coordinating regularly with MPOs to set greenhouse gas targets, share data on emissions metrics, and develop standardized methodologies for assessing reductions. This involves sharing data on VMT (vehicle miles traveled) and fuel usage to establish state benchmarks. The MPOs will have six months from the FHWA’s February 1st deadline to determine whether to adopt the state’s GHG targets or their own. We will be meeting with the MPOs in the coming week regarding these details. To that effort, NJDOT may leverage a single consultant funded through federal grants to help unify this process across the MPO regions. The department is poised to submit their final targets to FHWA, with the intention to make these documents public, ensuring transparency and community involvement.

The Carbon Reduction Strategy was in progress since December 2022, when the Carbon Reduction Working Group began the review process. This included developing strategies over the course of Winter and Spring 2023, in addition to resolving concerns brought forth by our leadership. Following our November 15th submission, FHWA will have 90 days to approve or deny the draft plan. (NJDOT CIA Team Planning & Environment Presentation, 2023)

In addition to deploying EV charging stations in line with our NEVI goals, NJDOT is exploring electrifying its own fleet and operations with technologies like electric garbage trucks. However, as we have seen this winter, concerns around reduced EV range and long charging times during cold winter temperatures could affect adoption goals if improvements in technologies do not continue. Regardless, all plans, targets, and strategies, in collaboration with MPOs, will undergo review and approval by FHWA. This process aligns with DOT’s recent guidelines for greenhouse gas reduction.

Resources

EV Infrastructure & Policy

New Jersey Department of Transportation. (2023). “NJ Approval Letter for EV Deployment Plan.” Retrieved from https://www.fhwa.dot.gov/environment/nevi/ev_deployment_plans/nj-approval-letter-fy24.pdf.

New Jersey Department of Transportation. (2023). NJDOT Electric Vehicle Infrastructure Deployment along New Jersey Alternative Fuel Corridors: Pre-bid Meeting Presentation. Retrieved from https://www.nj.gov/transportation/contribute/business/procurement/ConstrServ/documents/NJDOTNEVIPreBidMeetingOct172023PresentationRev.10-20-23.pdf

New Jersey Department of Transportation. (2022). “NEVI Program Overview.” Retrieved from https://dep.nj.gov/wp-content/uploads/drivegreen/pdf/nevi.pdf

U.S. Department of Transportation, Federal Highway Administration (n.d). National Electric Vehicle Infrastructure Formula Program, Fact Sheet. Retrieved from https://www.fhwa.dot.gov/bipartisan-infrastructure-law/nevi_formula_program.cfm

U.S. Department of Energy, Alternative Fuels Data Center. (n.d). Electric Vehicle Charging Stations.  Retrieved from https://afdc.energy.gov/fuels/electricity_stations.html

Carbon Reduction Efforts

Federal Register (2023). 23 CFR Part 490. National Performance Management Measures; Assessing Performance of the National Highway System, Greenhouse Gas Emissions Measure, Federal Highway Administration. Retrieved from https://www.govinfo.gov/content/pkg/FR-2023-12-07/pdf/2023-26019.pdf

New Jersey Department of Transportation. (2023). CIA Team – Planning & Environment: Discussions on National Performance Management Measure (GHG). Presentation by Sudhir Joshi. Retrieved from https://www.njdottechtransfer.net/wp-content/uploads/2023/12/5-Planning.pdf

U.S. Department of Transportation, Federal Highway Administration (n.d). Carbon Reduction Program, Fact Sheet. Retrieved from https://www.fhwa.dot.gov/bipartisan-infrastructure-law/crp_fact_sheet.cfm

Environmental Justice and Equity

Conley, Shannon. Konisky, David M. Mullin, Megan. (2023). Delivering on Environmental Justice? U.S. State Implementation of the Justice40 Initiative. Retrieved from doi.org/10.1093/publius/pjad018.

Argonne National Laboratory. (2022). Using Mapping Tools to Prioritize Electric Vehicle Charger Benefits to Underserved Communities. Retrieved from https://publications.anl.gov/anlpubs/2022/05/175535.pdf

U.S. Department of Energy. (2022). Incorporating Equity and Justice40 in NEVI and Beyond. Retrieved from https://www.energy.gov/sites/default/files/2022-10/Incorporating%20Equity%20and%20Justice40%20in%20NEVI%20and%20Beyond.pdf‘.

Workforce Development and Training

National Governors Association. (2023). Workforce Development in The IIJA, CHIPS, And IRA. Retrieved from https://www.nga.org/publications/workforce-development-in-the-iija-chips-and-ira/.

National Center for Sustainable Transportation. (2022). Workforce Implications of Transitioning to Zero-Emission Buses in Public Transit. Retrieved from https://escholarship.org/uc/item/3jb4b73d.

San Jose State University. (2020). Southern California Regional Transit Training Consortium: Skills Gap & Needs Assessment. Retrieved from https://transweb.sjsu.edu/sites/default/files/1932-Reeb-Southern-California-Regional-Transit-Training-Consortium-Needs-Assessment.pdf.

National Center for Sustainable Transportation. (2018). Emerging Clean Transportation Workforce White Paper. https://www.uvm.edu/sites/default/files/media/Emerging-Clean-Transportation-Workforce-White-Paper12202018.pdf.

Argonne National Laboratory. (2022). Using Mapping Tools to Prioritize Electric Vehicle Charger Benefits to Underserved Communities. https://publications.anl.gov/anlpubs/2022/05/175535.pdf

NEVI Deployment in Other States

Colorado Department of Transportation & Colorado Energy Office (2023). Colorado National Electric Vehicle Infrastructure (NEVI) Plan. https://www.codot.gov/programs/innovativemobility/assets/2023-update-of-colorado-plan-for-the-national-electric-vehicle-infrastructure-nevi-program.pdf.

Michigan Department of Transportation. (2023). Michigan State Plan for Electric Vehicle Infrastructure Deployment 2023 Update. https://www.michigan.gov/mdot/-/media/Project/Websites/MDOT/Travel/Mobility/Mobility-Initiatives/NEVI/FY23-MI-Plan-for-EV-Infrastructure-Deployment.pdf?rev=968c7cbcf92c4b2abb08573f2af0f9f5&hash=409ED1B68C1FBEE6E52E334690405162.

New Hampshire Department of Transportation. (2023). State of New Hampshire Plan For Electric Vehicle Infrastructure Deployment Update No. 1. https://www.dot.nh.gov/sites/g/files/ehbemt811/files/inline-documents/updated-nevi-plan-8-1-2023.pdf.

North Carolina Department of Transportation (2023). North Carolina Plan Update for Electric Vehicle (EV) Infrastructure Deployment Plan. https://www.ncdot.gov/initiatives-policies/environmental/climate-change/Documents/ncdot-electric-vehicle-deployment-plan.pdf.

Washington State Department of Transportation. (2023). Washington State Plan for Electric Vehicle Infrastructure Deployment July 2023 Update. https://wsdot.wa.gov/sites/default/files/2023-09/WSDOT-NEVI-Plan-Update.pdf.

Ultra High-Performance Concrete (UHPC) Applications in New Jersey – An Update

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UHPC for Bridge Preservation and Repair is a model innovation that was featured in FHWA’s Every Day Counts Program (EDC-6).  UHPC is recognized as an innovative new material that can be used to extend the life of bridges. Its enhanced strength reduces the need for repairs, adding to the service life of a facility.   

This Q&A article has been prepared following an interview with Jess Mendenhall and Samer Rabie of NJDOT, who provided an update on the pilot projects of UHPC around the state. The interview has been edited for clarity. 

Q.  While EDC-6 was underway, we spoke with your unit about the pilot projects being undertaken with UHPC.  Some initial lessons were shared subsequently in a featured presentation given to the NJ STIC.  Can you update us on results of those projects, and did they yield any benefits in the fields of safety or environmental considerations?

For the NJDOT Pilot Project, the thickness of the overlay was limited by the required depth for effectiveness, as well as the cost of the UHPC material and environmental permitting. To mitigate environmental permitting, we avoided any modifications to the existing elevations and geometry of the structure. Essentially, any removal of asphalt and concrete needed to be replaced to its original elevations.

UHPC overlays can significantly extend the service of bridge decks and even increase a structure’s capacity. Although safety improvements were not the primary objective of this application, there were rideability and surface drainage considerations in the design to enhance the conditions for the road users.

The environmental impacts of structural designs must be compared on the cradle-to-grave use cycle of the design at a project scale.  Having a focus on sustainability is imperative; however, it is more meaningful when resiliency is also considered.  While the greenhouse gas emissions of a volume of UHPC are higher than those of the same volume of concrete, UHPC enables the reduction in the amount of material required in structural designs and improves the durability of structures. Its exceptional compressive strength and toughness allow for the reduction of material usage. By minimizing maintenance requirements and extending the lifespan of infrastructure, UHPC reduces the consumption of materials, energy, and resources over time.

For example, we installed this overlay on 4 bridges as a preservation technique. Had we done nothing, they would have lasted approximately 10 more years. During that time they would have needed routine deck patching resulting in further contamination of the decks and in a condition that is no longer preservable and requires total deck replacement, with large volumes of concrete and much more environmental impact.

UHPC allowed us to take these decks that are still in decent shape and preserve them now with a relatively thin layer to make them exceed the service life of the superstructure and substructure.

Q. Has UHPC been incorporated into the design manual?

Figure 1. UHPC being placed by workers

It is not in our current design manual, but we are working on the revised design manual. UHPC is presently being used for all closure pores between prefabricated components, overlays, and link-slabs. I don’t think we are ready to standardize it quite yet. We used it on the 4 bridges and it will continue to be used, but we will not standardize it until the industry is more predictable and we get more experience to develop thorough guidelines and specifications. It is incorporated into projects as a special provision with non-standard items.

Q. Have you been receiving more requests to use this technology from around the state?

It is much more commonly specified by designers or requested for use on many of our projects. We have responded to nationwide inquiries from state transportation agencies and universities seeking our specifications or input on specific testing and procedures.

Q. What efforts do you think can be taken to encourage more adoption amongst local agencies, counties, etc.?

We are keen on inviting the counties to any training or workshop that we are hosting as well as sharing our lessons learned thus far.  I think they are aware of it.

Q. What kind of hurdles do you think exist that may limit widespread adoption?

It is possible that initial cost and industry experience with the material are still major limiting factors in adoption. We have also learned from specialty UHPC contractors that the innovation and availability of construction equipment geared for UHPC implementation are also lacking.  Bringing into focus the life cycle costs and with more implementations, we think many of these hurdles will be overcome. Additionally, once UHPC is used more in routine maintenance the implementation would be more frequent and widespread; we know there is interest specifically in UHPC shotcrete once it is available.

Q. Are you familiar with any training, workshops, or conferences that have been done for staff or their partners on this topic?

We participated in the Accelerated Bridge Construction (ABC) conference in Miami, Florida, the International Bridge Conference (IBC) in Pittsburgh, Pennsylvania and the New York State DOT Peer Exchange. In Delaware, we presented at the Third International Interactive Symposium on UHPC. We also participated in the development of a UHPC course for the AASHTO Technical Training Solutions (TTS formerly TC3) which is now published on the AASHTO TTS portal and available on our LMS internally. 

Q. Do you think there is any special training needed for the construction workforce to start using this technology?

Absolutely, the AASHTO TTS course and the EDC-6 workshops are geared towards the design and construction, TTS is more focused in the Construction. It’s an introduction to what to expect and how to implement it. UHPC is often used for repair projects, and many contractors may not have the experience or comfort with using the material.

Figure 2. UHPC Testing at Rutgers’ CAIT

Q. What are the results of the pilot projects of UHPC?

This Pilot projects program demonstrated that UHPC overlays can be successfully placed on various structures, the work can be completed rapidly to minimize traffic impacts — we estimated roughly four weeks of traffic disruption per stage, and the benefits of UHPC can help preserve the existing infrastructure. Compared to deck replacement, UHPC overlays can rehabilitate a bridge deck at exceptional speeds with unique constructability and traffic patterns, as implemented in all four structures. However, limitations exist, and further research is necessary to investigate the issues identified in the pilot project, but the potential of this material outweighs the existing limitations.

Q. Has there been long-term testing data developed to gather performance data?

To assess the performance of the UHPC overlay, we put together a testing program to include NDT as well as physical sampling and lab testing. This objective will be accomplished by first establishing baseline conditions through an initial survey followed by periodic monitoring of the UHPC-overlaid bridges over succeeding years. This will help NJDOT assess the performance of UHPC as an overlay. Overall, the results show the overlay bond is performing well.

Q. Has the data from the pilot project been used to research further applications?

Further applications for UHPC overlay are on new bridge decks/superstructures, and the data from UHPC overlay research project are being used for these projects. There is an interest in header reconstruction with UHPC. If deck joints need to be replaced, they should be constructed with conventional HPC with UHPC at the surface to provide the same overlay protection over the entire structure. Also, self-consolidating and self-leveling UHPC was preferred for the full-depth UHPC header placement to ensure proper consolidation around tight corners and reinforcement. This will be further explored for maintenance operations as well.

For future projects, in lieu of full-depth header reconstruction in a single lift, a partial depth header removal and reconstruction or alternatively two lifts of header concrete should be evaluated to coincide with the deck overlay, in which case the benefits of the fast cure times from UHPC can still be realized. Two of the four bridges experienced air voids throughout the placement. A UHPC slurry with no

fibers was placed in the identified air voids; since the voids contained exposed fibers, they were considered to create adequate bonding with the UHPC slurry.

Resources

NJDOT Technology Transfer (2021, November). Stronger, More Resilient Bridges: Ultra High-Performance Concrete (UHPC) Applications in New Jersey.  Interview with Pranav Lathia, Retrieved from:  https://www.njdottechtransfer.net/2021/11/29/uhpc-stronger-more-resilient-bridges/

Mendenhall, Jess and Rabie, Samer. (2021, October 20). UHPC Overlays for Bridge Preservation—Lessons Learned. New Jersey Department of Transportation. https://www.njdottechtransfer.net/wp-content/uploads/2021/11/NJDOT-UHPC-Overlay-Research-Project-EDC-6-Workshop.pdf

New Jersey Department of Transportation. (2021, October 20). NJDOT Workshop Report. New Jersey Department of Transportation. https://www.njdottechtransfer.net/wp-content/uploads/2021/11/NJDOT-UHPC-Workshop-Final-Report.pdf

Rabie, Samer and Jess Mendenhall (2022, December). Design, Construction, and Evaluation of UHPC Bridge Deck Overlays for NJDOT.  NJ STIC Presentation and Recording.  Retrieved from:  https://www.njdottechtransfer.net/2022/12/18/nj-stic-4th-quarter-2022-meeting/

Safety Behavior and Gender Split Differences in Micromobility: A Q&A Interview with Researcher

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The State of New Jersey has advanced policies, programs, and projects such as complete streets that encourage greater transportation modal choice and less dependency on the single-occupancy vehicle to address climate change and promote mobility and access for all users. The NJ Statewide Bicycle and Pedestrian Master Plan and Complete Streets policy seek to increase connectivity and micromobility safety through road diets and other infrastructure changes. New Jersey Department of Transportation (NJDOT) is also sponsoring safety programs that aim to reduce traffic related fatalities. In-depth research that looks at differences across gender, race, socioeconomic status and ability may assist in expanding policies and statewide initiatives that prioritize safety and accessibility for all road users.     

This Q&A article has been prepared following an interview with Dr. Hannah Younes, a post-doctoral researcher at the Alan M. Voorhees Transportation Center at Rutgers University, who focuses on cyclists and e-scooter behavioral patterns.  Her most recent study conducted in Asbury Park, NJ observed gender differences of chosen micromobility mode, helmet usage, and location. We interviewed her to better understand the data sources and methods used in the research, its limitations and explore the applicability and implications of her research findings to the field of transportation and future research. The Q&A interview has been edited for clarity.

Q. How was your research funded?    

This work was supported by the National Science Foundation under a grant called “Making Micromobility Smarter and Safer”. The lead on this is Dr. Clint Andrews at Rutgers University and there are several other principal investigators. My study acts as a part of this multi-year research.  

Q.  Can you share a brief overview of your findings? Are the results surprising or unique compared to past research?    

We are one of the only studies comparing the safety behavior of cyclists and e-scooter users across genders. Without considering gender, we found that one-third of cyclists wore a helmet. We also found in our observations that e-scooter users did not wear a helmet. It speaks to how important it is to have safe micromobility infrastructure, especially knowing that people are unlikely to wear a helmet. In the U.S., even if you give everyone a helmet, they’re probably not going to wear it. That’s just how it is. Keeping people safe in other ways is paramount.  

The temporary bike lane created as a part of Dr. Younes research. Asbury Park, NJ

We also found that a greater proportion of women were using e-scooters than bicycles. This is important because cycling has long been a male-dominated mode of transportation, for a variety of reasons. That is true across the world. There are studies that suggest women are less likely to cycle to work because of clothing like wearing a skirt or dress or heels, or fears of sweating. E-scooters remove that hurdle since they are not as prohibitive in terms of clothing and require less physical exertion. So, the vehicle type itself may make a difference. Moreover, women place more importance on bike lane infrastructure than men.  If we are seeing that e-scooters are the preferred mode for females, perhaps e-scooters can help narrow the gender gap in micromobility. 

Q.  Can you talk a little bit about the methods used for this study? How are these methods different from past research? Why did you choose to use traffic cameras for your observations?

This work was done using manual observations, a common method in micromobility studies. Previous research had used observations collected in the field. Instead of having observers in the field, we observed traffic camera footage at one intersection. Because we were observing gender and race as well as group behavior, the footage was useful as it allowed us to pause when needed. It was also less resource intensive than having a person stand in the field since no travel expenses were associated with the analysis.  

Q.  What challenges have you found in working with and interpreting traffic camera footage? With the improvement of AI technologies, do you think there will be an opportunity to automate this process in the future?  Are there any limitations you expect from this type of innovation?  

It is very time consuming and tedious to analyze this much camera footage. We analyzed 35 hours of footage. I would love to have analyzed more, but you have to draw the line somewhere depending on the resources available for the research or project study. Most of the time, we fast forwarded until a micromobility user was detected, but it still requires undivided attention. There is a possibility with current technology to incorporate AI technologies: to use computer vision to detect humans, which then can be manually viewed by a human to assess micromobility mode, gender, and helmet use. This would likely reduce the manual labor… It would be interesting to compare the computer vision model to the work I have done… Nonetheless, computer vision does not differentiate properly between pedestrians and e-scooter users, so it is prone to misidentification, which would lengthen the time taken to observe manually.  

The view from the intersection traffic camera. Asbury Park, NJ

At this point, computer vision cannot detect gender, helmet use, and group riding properly from traffic camera footage. More high-resolution images would be needed to differentiate gender and helmet use (like unobstructed face images) and group riding requires context clues like making eye contact, waiting for one another, etc. AI has the potential, but it is not there yet.  As time consuming as it is, I am confident that we detected every person, which is why we chose to observe the footage ourselves.  

Q.  What are the limitations of this study? Do you have plans for future research to address these?  How would you like to expand your research on this topic?   

The main limitation is the geographical scope of this research; it’s a lot of work for one city. We only analyzed the behavior of micromobility in one location, Asbury Park. It isn’t clear how much the results will translate from one location to another. Mode of transportation and behavioral use depends on many different factors that vary from location to location. There is evidence that the gender gap is smaller for e-scooter users in Brisbane, Australia, but not to the extent observed in Asbury Park. Same goes with helmet use. A larger scale study would be useful. Other limitations include the types of micromobility modes: we only observed shared e-scooters and privately owned bicycles in Asbury Park. So, we’re comparing two different vehicles and two different share types to one another. When analyzing the data, we must consider both of these factors. For example, are behaviors attributed solely to the vehicle or to the share type? Probably both. When you’re looking at the gender gap, is it because it’s an e-scooter or is it because it’s shared that there is a narrower gender gap?  

 An analysis comparing shared and privately owned e-scooters with shared and privately owned bicycles would be great. Differentiating between e-bikes and bicycles would be great too, although the resolution of traffic camera footage makes it very hard to differentiate between the two. Even with an observer onsite, it would be hard to detect, so you would need a survey, but this could alter behavior. In Asbury Park, a lot of people have privately owned e-scooters now, so we could do another study in 1.5-2 years and get additional insights in the same location.  

E-bikes are a growing mode of transportation, but even with traffic camera footage, it is very hard to tell an e-bike apart from a bicycle, so maybe in that case you would need somebody on site actually observing. You’re losing the ability to pause footage, but it might be more useful if you’re looking at e-bikes. Race and age were also very difficult to observe from the footage. It could be easier if someone was in person to observe in addition to the traffic camera footage. Even then, without asking directly the age and race/ethnicity of the user, there will be bias. There are a lot of different things to consider; it really depends on what the question is.  

Q.  How would you like this research to inform transportation agencies and practitioners in New Jersey and elsewhere?    

There are several key points. Users of shared e-scooters and privately owned bicycles are different and behave differently. E-scooter users are more likely to take risks like not wearing a helmet or riding on the road. Planners must ensure that the infrastructure keeps them safe. That is, implementing dedicated protected bike lanes that are connected to a greater network and adding traffic calming measures to slow the speeds of motor-vehicles like raised crosswalks or narrower traffic lanes.

Understanding the reasons behind lane use is important as well, as there are concerns for pedestrian safety. Our research observed that lane use was different; for example, 7 percent of male cyclists rode on the sidewalk, compared to 28 percent of female e-scooter users.

Additionally, having a shared e-scooter system in a city can increase female participation in micromobility use. It is a more gender equitable mode than bicycles. Other agencies might want to implement an e-scooter share program in their town.  

Q.  Your research shows that women were more likely than men to ride on the sidewalk while using an e-scooter or bike. Given that this strategy is illegal in most parts of the country, how can planners, engineers and policymakers use this information to increase feelings of safety for female micromobility users?     

This is really interesting. From my research, there is not a lot that I could say. Implicitly, one of the reasons for someone to ride on the sidewalk instead of the road is that they feel safer on the sidewalk. There is a need to ensure that micromobility users feel just as safe on the road–that is, implement a dedicated and protected bike lane, and provide a clear separation from motor-vehicles.

From our work, we know that there are other more complex factors at play: our research had clear results for road lane use with the implementation of the bike lane, but less clear ones for sidewalk use: sidewalk use was not significantly reduced by the presence of a pop-up bike lane. To encourage safe road use, ensuring a complete network would be a start. The pop-up bike lane was not connected to another bike lane going downtown, for instance. If you’re already coming downtown on the sidewalk, you might be more likely to stay there given the existing curb that would need to be crossed to go from the sidewalk to the pop-up bike lane.  

Representation of bidirectional bicycle lanes Image via Streetmix. Ensuring cyclists and e-scooter users have safe infrastructure as shown above is important for all road users’ safety.

Q.  NJDOT is sponsoring a program to ensure the implementation of the Statewide Bicycle and Pedestrian Master Plan. In what ways could this master plan or a future one align with the findings in your study?  

The results of this study reinforce that implementing a bike lane provides a layer of safety for micromobility users. Nearly all the increase in bike lane usage came from a reduction in traffic lane usage, not in sidewalk usage. There is so much research out there that shows that bike lanes save lives; in the case of a crash, someone in a bike lane is less likely to be injured. Ensuring that plans accommodate both bicycles and e-vehicles–like e-bikes and e-scooters–is also paramount.  

Q.  The Biden Administration has set a goal to achieve a net zero emissions economy by 2050. How might a shift toward micromobility help the nation reach its climate and carbon emission goals?    

Bicycles are zero emission vehicles. E-bikes and e-scooters produce few emissions, especially privately owned ones since they don’t require rebalancing. Rebalancing shared vehicles requires a car or van and those gasoline emissions are absorbed by those shared e-scooters. Having an e-vehicle do that for rebalancing helps to reduce those emissions. Bicycle-friendly infrastructure, which reduces motor-vehicle infrastructure such as the number of traffic lanes, or parking, can also reduce motor-vehicle use and induce more environmentally friendly travel.   

Q.  How could a focus on reaching these climate goals impact the way that planners and engineers design streets?    

Motor-vehicle travel is the most polluting transportation mode. A shift towards micromobility Infrastructure, particularly in cities, can help induce travel from eco-friendly modes and reduce motor-vehicle use. This should be in conjunction with other measures, such as increasing gasoline prices, increasing parking costs, and providing subsidies for eco-friendly modes.

Resources

Blickstein, S.G., Brown, C.T., & Yang, S. (2019). “E-Scooter Programs Current State of Practice in US Cities.” Retrieved from https://njbikeped.org/e-scooter-programs-current-state-of-practice-in-us-cities-2019/

Marshall, H. (2023). “How do Female Cyclists Perceive Different Cycling Environments? – A Photo-elicitation study in Stockholm, Sweden.” Retrieved from https://gupea.ub.gu.se/handle/2077/78209

NJDOT Technology Transfer. (2020). “Tech Talk! Launching Micromobility in NJ and Beyond.” Retrieved from https://www.njdottechtransfer.net/2020/02/25/launching-micromobility-in-nj-and-beyond/

NJDOT Technology Transfer. (2021). “How Automated Video Analytics Can Make NJ’s Transportation Network Safer and More Efficient.” Retrieved from https://www.njdottechtransfer.net/2021/11/08/automated-video-analytics/

NJDOT Technology Transfer.(2022). “Research Spotlight: Exploring the Use of Artificial Intelligence to Improve Railroad Safety”. Retrieved from https://www.njdottechtransfer.net/2022/08/19/researchspotlightairailroadsafety

Rupi, F., Freo, M., Poliziani, C., & Schweizer, J. (2023). “Analysis of Gender-Specific Bicycle Route Choices Using Revealed Preference Surveys Based on GPS Traces.” Retrieved from https://www.sciencedirect.com/science/article/pii/S0967070X2300001X

Salazar-Miranda, A., Zhang, F., Maoran, S., & Ratti, C. (2023). “Smart Curbs: Measuring Street Activities in Real-Time Using Computer Vision,” Retrieved from https://www.sciencedirect.com/science/article/pii/S0169204623000348?casa_token=XPecGlOM6UQAAAAA:vnISsmV2aoJ3iVJefEeqjM24R5izcs66bvukCQObjuSWGTNokotT4CG_1h8UfLih16wn3FMg_Jo [DA1] [KR2] 

Von Hagen, L.A., Meehan, S., Younes, H., et. al. (2022), “Asbury Park Bike Lane Demonstration,” Retrieved from https://storymaps.arcgis.com/stories/c014811ac0c14735bc9c9adc2639e88f.

Younes, H., Noland, R., & Andrews, C. (2023). “Gender Split and Safety Behavior of Cyclists and E-Scooter Users in Asbury Park, NJ,” Retrieved from https://www.sciencedirect.com/science/article/abs/pii/S2213624X2300127X#b0055.

Younes, H., Noland, R., & and Von Hagen, L.A. (2023). “Are E-Scooter Users More Seriously Injured than E-Bike Users and Bicyclists?” Retrieved from https://policylab.rutgers.edu/are-e-scooter-users-more-seriously-injured-than-e-bike-users-and-bicyclists/.

Q&A: What’s EPIC2 about Internally Cured Concrete?

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Enhancing Performance with Internally Cured Concrete (EPIC2) is a model innovation in the latest round of the FHWA’s Every Day Counts Program (EDC-7). EPIC2 is recognized as an innovative new technique that can be used to extend the life of concrete bridges and roads. Internal curing increases concrete’s resistance to early cracking, allowing the production of higher-performance concretes that may last more than 75 years.

This Q&A article has been prepared following an interview and follow-up correspondence with Samer Rabie and Jess Mendenhall of the New Jersey Department of Transportation. The Q&A interview has been condensed and edited for clarity.

Q. What is Internally Cured Concrete, and how does it differ from traditional concrete?

A common issue with high performance concrete (HPC) bridge decks is that soon after the curing is done, they develop fine shrinkage cracks spread throughout the deck. Even this fine cracking can reduce the service life. In the past, we have used crack sealing materials as a mitigation effort, but when we learned about internally cured concrete, we shifted our focus to see if we could adopt it in New Jersey.

Figure 1. Illustrating the difference between conventional and internal curing

Autogenous or chemical shrinkage is specific to HPC concrete, where the w/c ratio is less than 0.42. It is due to self-desiccation, which is water consumed by the cementitious materials after setting, and that is one where internal curing can help.

There are multiple methods to implement internal curing. The method that we are considering involves  modifying a conventional concrete mixture to an internally cured concrete mixture by replacing a portion of the fine aggregate (sand) with lightweight fine aggregate. This lightweight fine aggregate (LWFA) is saturated with internal curing water, typically estimated at 7lbs of water for every 100lbs of cementitious materials used in the mixture. Next, the amount of LWA required for this amount of internal curing water is determined based on the mass of the internal curing water and the absorption of the LWFA. Once the total volume and mass of lightweight aggregate are determined, the volume (and mass) of the fine lightweight aggregate are adjusted so that the volume of LWFA and fine aggregate in the internally cured mixture is equal to the volume of the fine aggregate in the original mixture.

The LWFA will provide internal curing water within the concrete mix during curing, and prevent a condition that occurs in low W/CM ratio systems where the capillary water within the concrete matrix pores will be consumed without complete cement hydration, which can lead to cracking of the concrete matrix.

Q. How does Internally Cured Concrete improve performance?

Internal curing improves the performance of concrete by increasing the reaction of the cementitious materials and reducing internal stresses that typically develop in high-cementitious content mixtures if insufficient internal curing water is present. However, in addition to conventional curing which supplies water from the surface of concrete, internal curing provides curing water from the aggregates within the concrete. This provides a source of moisture from inside the concrete mixture, improving its resistance to cracking and overall durability.

Q. Are there any limitations on the use of internally cured concrete?

Internal curing is extremely versatile and  can generally be used anywhere traditional concrete is used. Most of the process is the same, and aggregates can be pre-saturated as needed. It follows the norms of industrial concrete production, making it accessible to any producer already familiar with the state of practice. Most of the implementation process is similar to conventional concrete.

Figure 2. Workers applying internally cured concrete to a bridge deck.

Q. What New Jersey sites were picked for use in internally cured concrete, and why?

We started with a list of all of our bridge projects, specifically projects that needed deck replacement and superstructure replacement. We then further targeted projects that allowed us to focus on implementation and quick delivery time rather than constructability and other additional challenges. We looked at projects with straightforward staging and geometry and prioritized projects with twin bridges (for example, northbound and southbound). This would allow us to do one bridge with traditional HPC and the other with internally cured HPC, providing us with an excellent controlled opportunity to study and compare the results.

Various sites have been screened throughout the state. Currently, eight bridges are under consideration, with a project scope of work of deck and superstructure replacement. The rationale included the project scope of work, CIP deck slabs, project schedule, staging constraints, and avoiding heavily skewed bridges.

Q. Have any life cycle cost analyses been performed?

We have not prepared one ourselves, but we do plan on doing so in the future. First, we will need to get these projects out to construction and get actual cost data. We’re expecting higher upfront costs, but if cracking is reduced then the life cycle costs and future maintenance and reconstruction needs can be significantly reduced.

Q. In what ways do you think people can be better educated on the implementation of EPIC2?

We have presented to many of our stakeholders in our capital program to discuss the topic, and now that it is an EDC initiative,  decision makers are acknowledging its value. The Federal Highway Administration is also planning on conducting workshops and peer exchanges between contractors, concrete suppliers, and other agencies like New York State DOT, which have already done this. All of these are extremely valuable.

We first heard about internally cured concrete during a peer exchange in 2021 with the New York State DOT. It was under the banner of EDC-6, and they took us out on several bridges where we noted that they have significantly reduced the typical shrinkage cracking that is common with High Performance Concrete. So that was an eye opening experience for us, and I know it would be valuable to others. The fact that it is now its own initiative in EDC-7 helps facilitate implementation.

Q. Is special training needed for contractors to work with internally cured concrete?

From our research and experience with other agencies, the finishing should not be significantly different from conventional HPC. The process at that point will be almost identical to placing traditional concrete, so there won’t be any learning curve or time spent on getting workers to learn how to deal with a new material. In fact, most contractors say that the mixture is easier to work due to improved pumpability as the material is quite smooth. I think the crucial step will be to coordinate with concrete production plants that are creating the mixes.

Figure 3. States that have implemented EPIC2 on their roads or bridges

Q. Where else has internally cured concrete been implemented?

So far it has been used in bridge decks in many states, including New York, Ohio, and North Carolina, among others. It has also been used in pavement and pavements in Kansas, Texas and Michigan.

Q. What is the future of internally cured concrete in New Jersey?

We hope these projects will be successful, and that our current crop of projects will result in some valuable lessons learned. In the long term, I believe the goal would be that all of the bridge decks would use an internally cured mixture. I can also see this being used for patching and deck repair jobs. But ultimately, the goal would be for this to become the new standard for bridge decks across the state.

Resources

Federal Highway Administration. 2023 Internally Curing Concrete Produces EPIC2 Results. https://www.fhwa.dot.gov/innovation/innovator/issue98/page_01.html

Federal Highway Administration. 2023. Enhancing Performance with Internally Cured Concrete. https://www.fhwa.dot.gov/innovation/everydaycounts/edc_7/docs/EDC-7FactsheetEPIC2.pdf

Federal Highway Administration. (2018, June). Concrete Clips: Internal Curing. https://www.youtube.com/watch?v=b6WREFmacaM

New York State DOT Standard Specifications (2021). Standard Specifications. New York State DOT. https://www.dot.ny.gov/main/business-center/engineering/specifications/busi-e-standards-usc/usc-repository/2021_9_specs_usc_vol2.pdf

National Concrete Pavement Technology Center Internal Curing Resources. (2022). Internal Curing. Iowa State University. https://cptechcenter.org/internal-curing/

Internal Curing. (2020). Oregon State University. https://engineering.oregonstate.edu/CCE/research/asphalt-materials-performance-lab/materials-research-concrete-materials/Internal-Curing

Pacheco, Jose. (2021, October). USDOT Workshop Report, Bureau of Transportation Statistics. Wisconsin Department of Transportation. https://rosap.ntl.bts.gov/view/dot/62607

Weiss, Joseph. (2015, July). Internal Curing Technical Brief. Federal Highway Administration. https://www.fhwa.dot.gov/pavement/concrete/pubs/hif16006.pdf