R919030 – UHPC (Phase-V) Thin-Bonded Overlay on Deteriorated Bridge Decks
Typical concrete overlay materials for existing bridge decks include latex-modified concrete, low slump dense concrete, and polyester polymer concrete. Polyester polymer concrete overlays are currently the most popular choice in New Mexico. However, the New Mexico Department of Transportation (NMDOT) has observed that polyester polymer concrete overlays are expensive and often need rehabilitation in just a few years.

Previous research has demonstrated that ultra high-performance concrete (UHPC) has the potential to increase service lives of bridge deck overlays and subsequently, the underlying concrete deck, because it has exceptional durability properties and contains silica fume that facilitates bond to substrate concretes. This research project will document, monitor, and assess the field implementation of a UHPC overlay produced with local materials on New Mexico Bridge #9706 in Socorro, NM. This will be the first non-proprietary UHPC overlay constructed in the United States.

R920050 – Determining Effectiveness of Wildlife-Vehicle Collision Mitigation Projects Phase II
The research is aimed at estimating passage rates or relative use of crossing structures for large mammals and identify other wildlife species using crossings at constructed and planned wildlife-vehicle collision mitigation projects for a 2-3year period. In instances where fencing will be constructed during the study, we will compare use of crossing structures over time to evaluate the effectiveness of the fencing.
The specific objectives of this study are to:

• Compare wildlife passage rates or relative use of crossings with studies done in other western states.
• Identify infrastructure shortcomings or other factors that contribute to low passage rates or low relative use rates.
• Collate and review wildlife-vehicle collision and carcass collection data to determine the effectiveness of constructed projects in reducing wildlife-vehicle collisions, or at least document baseline wildlife-vehicle collision rates for planned projects.
• Create a guide for designing effective wildlife crossings and for improving existing drainage structures for mule deer (Odocoileus hemionus), elk (Cervus elaphus), black bear (Ursus americanus) and Mountain lion (Puma concolor).

R922030 – Solution to Interfacial Delamination of NMDOT’s Asphalt Pavements
To find a solution to delamination issues of New Mexico pavements, the project was initiated to identify and evaluate the following factors:

• Debonding of the tack coat from the top or bottom layer: due to poor interlayer bond caused by dissimilar material systems, improper choice of tack coat (type), lack of tack or application rate, inadequate or excessive breaking and curing of tack coat. It is worthwhile to mention here that the Department does not have acceptance or performance tests for tack coats.
• Failure within the layer: traffic- and pavement design related causes (e.g., slippage between layers due to heavy traffic, unstable or poor mix, excessive cyclic stresses at the interface of two layers)
• Damage and fracture within the interface or tack coat layer: caused by seepage of water through the surface layer, improper compaction, aging, and mismatch in thermal expansion and contraction between two layers and/or interface tack layer due to seasonal change in temperature.

R922040 – Develop a Balanced Asphalt Mixture Design Procedure
The NMDOT uses the Superpave method to design asphalt mixes which have shown poor cracking performance, although rutting performance is favorable. In a balanced mix design (BMD) approach, an asphalt mix will be designed to balance these two distresses; it will allow more rutting within a reasonable amount and reduce the long-term cracking.
The goal of this research is to develop a balanced mix design procedure, not only  considering traffic and weather conditions of a region, but also  performance driven rutting and cracking criteria.
The development of a step-by-step BMD procedure (mix volumetrics) will include multiple mix type (e.g., HMA and WMA), different performance grade (PG) binder content, aggregate gradation and type, and aging conditions.

R922050 – Conduct a Friction Testing Program, Data Analysis and Effectiveness of the NMDOT Open Grade Friction Course Program
The NMDOT conducts friction testing year-round on all state-owned roads and collected data are stored in database. There is a lack of guidance on what new roads should test at for open-graded friction course (OGFC), concrete, or chip seal, or any correlation with traffic safety, smoothness, or resurfacing criteria. Findings from this friction data focused research will be applied to pre- and post- OGFC, to determine if the friction courses are effective.

R922060 – Dust Mitigation Monitoring Project Phase II
NM DOT HSIP Dust Mitigation Projects. Since 2015, the New Mexico Department of Transportation has programmed $2.5 million in Highway Safety Improvement Program {HSIP) funds for dust mitigation activities at the Lordsburg Playa on both sides of I-10. In 2018, dust mitigation efforts in the Southern Playa {Road Forks) area were initiated including livestock exclusion, keyline plowing, printing, seeding, tackifier, and fencing. In 2020 and 2021, dust mitigation efforts in the Northern Playa area were initiated including livestock exclusion, channel/erosion control, keyline plowing, printing, seeding, tackifier and fencing. The objective of Phase II study is to determine the effectiveness of land use interventions on mitigating blowing dust and the frequency of dust-related traffic crashes

R922070 – Countermeasures to Improve Pedestrian Safety on Arterials
This project explores the most effective countermeasures to reduce pedestrian fatalities on arterial streets, using Central Avenue in Albuquerque – a pedestrian fatality hot spot – as a case study and extrapolate those results to other locations, allowing for results to not only improve traffic safety in Albuquerque, but in other municipalities across the state, region, and country. The research focuses on pedestrian safety but also addresses traffic safety outcomes for motor vehicle users and bicyclists. The treatments to be explored include a bus rapid transit (BRT) system, high intensity activated crosswalk (HAWK) beacons, turning restrictions, leading pedestrian intervals and road diets.

R923020 – Augmented Reality for Highway Bridge Element Inspection

Condition assessment for bridges is a methodical task which requires substantial time, attention to detail, and precise documentation. As such, a single bridge inspection requires several hours of lane closures and multiple trained personnel to complete. Importantly, the recent transition to element level condition ratings has increased the details necessary to compile bridge inspection reports. While allowing more effective evaluation of bridge deterioration and prioritization of maintenance tasks, this has also increased the time and effort required from inspectors. It has also led to less consistency in how information is documented by bridge inspectors. These challenges present an opportunity for NMDOT (and other agencies) to leverage augmented reality (AR) techniques to assist in specific inspection tasks and reduce the cognitive load on inspectors, helping them to execute faster while maintaining high performance. As bridge inspection guidelines continue to evolve, AR can also provide a platform to quickly integrate new automated inspection technology and changing requirements into the workflow.

Specifically, NMDOT is expecting the following from AR research to:

• Facilitate routine tasks accelerating the inspection process and reducing mental fatigue.
• Provide heads-up access to relevant element and defect codes from the AASHTO manual.
• Produce historical overlays of previous inspections, thus allowing better judgements on the progression of deterioration.
• Leverage artificial intelligence (AI) to automatically label and measure defects (with a focus on concrete cracking and spalling), thus automating the generation of condition reports and well as providing additional insights. Importantly, the development of the AR interface will follow a user-centered design strategy to ensure that the interface is easy to use, easy to train for, and inspectors can interact with AI elements in order to ensure consistent performance.

R923030 – Chip Seal for Uniform Usages

Chip seals are one of the most popular pavement preservation treatments for asphalt pavements due to their ability to seal the existing road surface from moisture damage and oxidation, improve skid resistance, seal minor racks, and delay deterioration. They consist of a uniform spray application of an asphalt binder followed by a uniform application of aggregate coat cover which is then rolled with pneumatic tire rollers to achieve the desired embedment. This simple process can be conducted using local maintenance personnel with minimal equipment requirements, making it a cost-effective option.

NMDOT has not adopted a specific chip seal design procedure, and rather each district has independent methods to determine the material application rates, generally based on experience. The materials used vary throughout the state based on local availability. Recently, the use of reclaimed asphalt pavement (RAP) as chip seal aggregate has been adopted as an alternative to virgin aggregate due to the sustainability benefits associated with it.

The objectives of or this research are to:

• Evaluate current NMDOT chip seal practices across the state of New Mexico, specifically materials and application rates. Assess the impact of these practices and/or factors on the performance based on available PMS database.
• Develop a chip seal design procedure, addressing both local materials and geographic conditions across the state of New Mexico.
• Develop statewide chip seal construction specifications.
• Develop project selection criteria for NMDOT to obtain optimum performance and treatment life from chip seal applications, such as skid resistance and minimum chip loss.

R923040 – GEOSYSTEMS Green Infrastructure

The objective of the research is to address future climate change and resiliency issues and mitigate the impacts to NMDOT’s rights-of-way by identifying areas where special environmental consideration and treatments should be considered.

This project will help the Environmental Bureau identify the areas where projects will have the most beneficial impact and will help NMDOT identify areas that should receive special consideration due to their environmental assets, such as habitat for endangered species, wildlife corridors, impaired rivers, areas with high biodiversity, etc.

Anticipated Benefits

• Protect NMDOT’s assets by addressing erosion and sediment deposition threats to existing infrastructure.
• Improve water quality by managing stormwater runoff.
• Decrease habitat fragmentation through ecological restoration and revegetation.
• Aid and protect numerous wildlife species including species such as pollinating insects and birds by planting and protecting pollinator habitat.
• Improve safety by reducing collisions with wildlife in important wildlife corridor areas.
• Improve air quality by capturing greenhouse gasses with an increase vegetative cover.
• Help identify wetland banking sites significant enough to address NMDOT future needs.

R923050 – Polymer Concrete Joints for Precast Bridge Elements

The overall objective of this project is to equip the New Mexico Department of Transportation (NMDOT) with the science and tools towards implementing a polymer concrete alternative solution for field joints of precast bridge members for accelerated construction.

There is a growing interest nowadays to find other alternatives and choices for bridge deck and ABC connections. Among potential candidate materials, the polymer concrete (PC) mixes stand out as an exceptional option for many reasons. PC can be sourced locally using more common and available materials and does not need to be proprietary, unlike UHPC that needs special additives and admixtures blends as well as steel fibers (which can be sometimes challenging to domestically source). PC provides much better mechanical properties (e.g., sustained tensile strength, superior bond behavior, high shear strength, etc.), durability, and flowability when compared to conventional concrete or standard grouts.

The polymer concrete alternative is to be comparable to what the NMDOT has recently implemented using ultra-high-performance concrete (UHPC) solutions. The NMDOT will leverage several years of research at the University of Nevada, Reno (UNR) in the area of polymer concrete and non-proprietary UHPC mix development and applications for accelerated bridge construction (ABC). UNR hosts world-class structural and large-scale testing facilities, as well as the materials laboratories under the Western Regional Superpave Center, to conduct a comprehensive experimental program that support the implementation tools that NMDOT requires.

R923070 – UAS Platform and Personnel Development and Preparation through Lab and Site Testing

In recent years, there has been growing interest in the use of UAVs for bridge inspections. Traditional visual inspection methods are expensive, time-consuming, and inefficient. UAS offers several advantages over visual inspection, such as the ability to fly close to inaccessible bridge locations, capture high-quality images using high-resolution cameras, and reduce labor costs. These benefits demonstrate the considerable potential of UAS for bridge inspection.

This research project aims to enhance the current bridge inspection practices in New Mexico State and achieve technology transfer purpose. The benefits to initialize the UAS-based bridge inspection in New Mexico States are tremendous, including but not limited to:

• Inspection efficiency improvement: Comparing to point-by-point manual data collection, UAS-based inspections provide a more efficient solution to field data acquisition.
• Cost savings: Efficient data collection process will significantly save cost due to lower labor allocation requests (mainly pilots and assistance), shorter period of traffic closures, and neglectable cost for hard-to-access locations (no requirement for scaffolding and crane).
• Safety improvement: UAS-based inspections provide a viable solution to avoid working at heights/traffic for inspectors and further improvement to safety.
• Fast and objective data interpretation: Advanced algorithms will provide the opportunity for automated data interpretation in a timely way. Development of easy-to-use software will enable simplified implementation of automated data interpretation algorithms.
• Inspection frequency acceleration: With the development of efficient and cost-effective UAS-based bridge inspection program, the inspection frequency could be increased to further improve the overall transportation infrastructure safety.

R924020 – Comparing Resistivity and Conductivity in Metal Culverts

Currently, NMDOT uses the “2018 NMDOT Culvert Resistance Spreadsheet” (CRS) when estimating the service life of culverts. The values of resistivity in the CRS for different types of culverts of varying material (steel, concrete, aluminum, plastic, etc.) and of varying wall thickness with different corrosive inhibitor coatings were collected from manufacturers’ specification literature. With all these manufacturers’ values being reported in resistance (ohm-cm), it was assumed that the electrical conductance (milliSiemens per meter, mS/m) values reported by the Natural Resources Conservation Services (NRCS) for soils throughout NM were indirectly proportional to each other, based on Ohm’s law. Furthermore, the resistivity of the soil is determined in-situ adjacent to the culvert and the values reported by NRCS are from EC tests conducted in a lab from field-collected soil samples. These two methods, in-situ and laboratory are significantly different in procedure and produce values of different units, ohm-cm (resistivity) and mS/m (conductivity), respectively. It is assumed that the laboratory test is more accurate than the field tests, which will be evaluated in this proposed project. Providing a better understanding of and evidence that these two methods, although different, produce results that are indirectly proportional to each other will enhance NMDOT’s continued usage of their CRS when calculating service life of culverts.

The main objectives of this proposal are as follows:

• Conduct a literature review of similar work on culvert service life estimation coupled with field and laboratory analysis. Research various (inexpensive and expensive) in-situ and laboratory soil testing equipment to be used for this study and then provide recommendations for NMDOT.
• Test various (inexpensive and expensive) in-situ and laboratory soil testing equipment on approximately 20 sites throughout NM.
• Compare service life estimates to existing removed culverts with soil samples tested in-situ and in the laboratory and measure corrosive effects on these removed culverts.
• Validate the assumptions made in NMDOT CRS for culvert service life estimates.
• Adjust the CRS if needed.

R924060 – Zuni Bowl and One Rock Check Dam Research – Phase 1A

There is a popular series of erosion control structures being built to mitigate small channel head cuts across the state of New Mexico. It is a Zuni Bowl followed by a One Rock Check Dam: a small plunge pool that is constructed of hand placed rip rap or native rocks followed by a small check dam that is also constructed of hand placed rip rap or native rocks.

Hydraulic laboratory test results are needed to develop design equations and standards for the Zuni Bowl and One Rock Check Dam for control of erosion affecting NMDOT drainage structures. A digital computational fluid dynamic (CFD) model of the Zuni Bowl and One Rock Check Dam can be used to develop standard equations for this energy dissipator.

This investigation will justify NMDOT’s acceptance of the Zuni Bowl followed by a One Rock Check Dam as solution for addressing head cutting or outlet scour affecting NMDOT structures.

The specific objectives of this study are to:

• Survey the control literature for information relevant to the evaluation and specifications to use Zuni Bowl and One Rock Check Dam and other erosion/sediment controls in New Mexico.
• Locate and describe individual controls which exemplify ones that could be used within NMDOT Right-of-Way (“ROW”).
• Generate an inventory of existing representative and exemplary controls, including locations, photos, and field notes that will serve to inform the evaluation and specification of such structures through research.
• Coordinate with watershed restoration agencies and professionals to gather relevant design criteria, recommendations, and existing documents and research.
• Organize and instruct a multiple-day training workshop for NMDOT personnel to learn about the use of Zuni Bowl and One Rock Check Dam and other erosion/sediment control structures in New Mexico ROW.
• Observe and participate in the NMDOT-lead construction of controls as part of the Environmental Bureau’s Dust Storm Mitigation and Safety program.

R924070 – Development of UAS-enabled Bridge Deck Inspection System from Investigation to Implementation

The NBI condition ratings serve as the fundamental basis for the collection of structural safety data during inspections. They enable the assessment of the physical state of bridge components, including the deck, superstructure, and substructure, by comparing them to their as-built condition. By taking into account the severity and extent of existing deterioration, these ratings provide an overview of the overall condition of the components. As the bridge deck is the component that is most directly impacted by traffic loads, it is crucial to maintain an accurate and current assessment of its condition. Regular inspections for bridge deck are essential for ensuring the safety and soundness of the entire bridge structure. To initialize the pilot project of UAS-based bridge inspection in component level, bridge deck is identified as the target component for this proposed project.

For this research project, the challenges for bridge deck inspection will be addressed by a UAS-based bridge inspection system with automated data collection and data interpretation. In the first stage, the automated data collection system will be developed. Where the UAS platform with various sensors will be developed. Then, preliminary flight testing will be performed for the developed UAS platform. Meanwhile, bridge deck data collection strategies for different sensors and environmental factors will be investigated. Finally, a recommendation will be developed for UAS-based bridge deck data collection under various scenarios. In the second stage, a data interpretation system will be developed. Where various data processing techniques and machine learning algorithms will be investigated to achieve reliable data interpretation that match the requirements for NBI rating systems. In the third stage, easy-to-use software will be built based on the algorithms developed in the second stage. In addition, the software will be implemented by using the field collected data and a tutorial will be prepared for NMDOT use. Last, the research outcomes from the proposed project will be delivered to NMDOT personnel as a technology transfer. A training workshop will be hosted to NMDOT personnel to gain knowledge of UAS-based bridge inspection. Besides, a site demonstration will be hosted to NMDOT personnel to show the developed UAS platform working on the site and software implementation. As a part of the research outcomes, a guideline for UAS based bridge deck inspection will be drafted.

R924080 – Synthesis of Feasibility Analysis of Ultra High-Performance Concrete for Prestresses Concrete Bridge Application – Phases I to IV

Since 2009, with backing provided by New Mexico Department of Transportation (NMDOT) funding, a collaborative research effort has been underway to explore the feasibility of incorporating Ultra-High-Performance Concrete (UHPC) into bridge design across the state. This endeavor has encompassed a wide range of research activities, from literature review, mixture development, and parametric studies of bridge designs to mechanical property assessment and durability testing, structural design, construction, and monitoring of a UHPC-girder bridge completed in 2017, and more. Since this project was initiated, it has been successfully extended from the initial phase I to the current phase V. Given the extensive and detailed nature of the reports associated with each phase of the research, the NMDOT recognizes the need for a more streamlined approach. To facilitate a more efficient understanding and utilization of the research findings, the NMDOT aims to consolidate these individual reports into a single comprehensive synthesis. This synthesis will serve as a condensed yet comprehensive document, encompassing the entirety of the research initiatives, high-level findings, and the roadmap that delineates the course of action for all five UHPC research phases.

There are three specific objectives of this research:

• Compile the individual reports (Phases I, II, III, IV, V) into a single synthesis, providing a concise overview of research initiatives and high-level findings.
• Develop a roadmap to incorporate UHPC into bridge design in New Mexico, based on the research findings.
• Ensure that the compiled synthesis is practical and accessible for NMDOT personnel, enabling them to implement the research findings effectively.

R924090 – Advancing High RAP Asphalt Mixtures toward Pavement Sustainability and Net Zero Carbon Emissions

The state of New Mexico is facing a tough job of weathering climate change and designing a sustainable (carbon reduction) roadway system for the people. The New Mexico Department of Transportation (NMDOT) deals with extreme temperature rise, occurrence of wildfire, increased rainfall intensity, flooding, extended summers, and more severe droughts. These natural hazards and ever-increasing material and construction costs have wrought significant damage to the roadway network throughout the state. Modem asphalt mixture designs not only prepare new and existing roadways that are not immune to climate change, but also provide economic and social opportunities for the people, especially in remote and rural areas, creating inclusive and connected economies.

Carbon emissions are a significant component of pavement sustainability and resilience. In 2022, the asphalt pavement industry in the United States established goals for climate stewardship to achieve net zero carbon emissions by 2050. The industry has also identified significant tactics, research, and implementation gaps required to achieve those goals, including the appropriate use of reclaimed asphalt pavements (RAP) and other recycled materials in asphalt mixtures. According to the most recent asphalt pavement industry survey, the average RAP content in asphalt mixtures for New Mexico is around 20%, which is slightly lower than the national average. Using more RAP will provide NMDOT with significant cost savings and reductions in carbon emissions associated with the production of asphalt mixtures and the construction of asphalt (flexible) pavements.

This project will advance the responsive use of high RAP asphalt mixtures in New Mexico, providing NMDOT with significant cost savings and improved transportation systems for the traveling public. Increasing the RAP content in asphalt mixtures from 20% to 40% while improving pavement performance could reduce the material cost by $10 per ton and reduce carbon emissions by 8%. These economic and environmental benefits would be substantial to NMDOT and the people of New Mexico, considering that over 3.5 million tons of asphalt mixtures are produced annually across the state. This research will also position NMDOT at the forefront in advancing pavement longevity and sustainability while allowing NMDOT to participate in USDOT’s national efforts and collaborate with other state DOTs interested in using high RAP asphalt mixtures.

The overall objective of this research is to advance high RAP asphalt mixtures toward pavement sustainability and net zero carbon emissions in New Mexico. Specifically, the research seeks to

• Develop mix design strategies to improve the long-term pavement performance and life span of high RAP asphalt mixtures.
• Determine the multi-cycle recyclability of high RAP asphalt mixtures.
• Quantify the economic and environmental benefits of high RAP asphalt mixtures through LCCA and LCA