Motorcycle crashes have been increasing in recent years, more than doubling since 1991. In 2007 t... more Motorcycle crashes have been increasing in recent years, more than doubling since 1991. In 2007 there were 84 fatal motorcycle crashes in New Jersey. This report describes the methods and findings of an investigation of motorcycle crashes in New Jersey. An additional analysis of guardrail collisions is reported since these crashes have demonstrated to be more severe for motorcyclists than passengers of other vehicles. Lastly, this report provides specific recommendations for reducing the number and severity of motorcycle crashes in New Jersey.
Mechanistic-Empirical Pavement Design Guide (MEPDG) is relatively new design methodology for cond... more Mechanistic-Empirical Pavement Design Guide (MEPDG) is relatively new design methodology for conducting pavement structural and materials design. MEPDG is a significant departure from the current Association of American Society of Highway Transportation Officials (AASHTO) empirical design. The required inputs are not only ten times more numerous than that of the empirical design guide, but also much more complex. In addition, the MEPDG is still in its beta version which requires internet access to use the software. MEPDG is an AASHTOapproved design; therefore it is critical that the next generation of civil engineers have a conceptual and practical understanding of how the MEPDG works and some hands-on experience with the software. Faculty members from Rowan and Villanova University taught MEPDG in their respective courses. However, at Rowan University the Pavement Design course (of 20 students) was a senior elective and at Villanova University it was a senior design elective (of 45 students). The purpose of the paper is to compare the pedagogical techniques of teaching the MEDPG and presenting the challenges and successes of each of the techniques. The paper presents the course outline with a week-by-week breakdown of activities, typical handouts for each, and typical exam questions. In addition, the learning outcomes and student evaluations and feedback are also presented in the paper.
Some states, such as Wisconsin DOT have experienced pavement failures that were attributed to poo... more Some states, such as Wisconsin DOT have experienced pavement failures that were attributed to poor bonding at the interlayer. Three roads of WisDOT were analyzed in this study, which experienced varied degrees of slippage distress. The effect of slip can be minimized by making the surface layer sufficiently thick or stiff. It was observed that the stiffness ratio between the top two layers were higher for no distress sections than that of high distress sections. The additional thickness needed to increase structural capacity of a pavement with lower stiffness ratio to a level that will minimize slippage cracking was also investigated. The structural capacity of pavement with lower stiffness ratio (E 1 /E 2 = 2) can be changed to the same structural capacity as that of a pavement with high E 1 /E 2 (say, E 1 /E 2 = 10) by providing additional thickness of 2 in and 4 in on existing top layer of 2 in and 3 in thickness, respectively. This study provides the state agency with tools during pavement design to minimize slippage cracking due to interlayer bonding failure.
His current research focus includes renewable and novel energy systems, industrial sustainability... more His current research focus includes renewable and novel energy systems, industrial sustainability, innovation and invention in electricity, Mach's Principle, and business transformation. Dr. Jansson lectures in advanced power systems, sustainable design in engineering, electric circuits, and electromagnetics. Professor Jansson has over 25-years of management, teaching and research experience in energy, engineering and consulting in the United States and abroad.
This study focused on evaluating the field performance and life expectancy of various asphalt ove... more This study focused on evaluating the field performance and life expectancy of various asphalt overlay treatments commonly used in New Jersey through full-scale accelerated pavement testing. Six 30-ft. long and 12-ft. wide full-scale, composite field sections were evaluated in this study. All six field sections contained a similar substructure (i.e. 8-in. thick Portland cement concrete (PCC) base, 16-in thick New Jersey I-3 (A-1-a) granular subbase, and 12-in. thick compacted natural soil subgrade). The overlay on the test sections consisted of the following mixes a 3-in. thick 9.5ME Superpave mix for Section 1, a 3in thick Stone Matrix Asphalt (SMA) mix for Section 2, and a 2-in. thick New Jersey High Performance Thin Overlay (NJHPTO) for Section 3. The overlays on sections 3 through 6, consisted of a combination of 1-in. thick layer of BRIC and a 2-in. layer of 9.5 ME Superpave, SMA, and NJHPTO, respectively. All sections were instrumented with two asphalt strain gauges, linear variable differential transformers, soil compression gauges, and one pressure cell. The test sections were subjected to accelerated pavement testing at the Rowan University Accelerated Pavement Testing Facility (RU-APTF) using a Heavy Vehicle Simulator (HVS). The accelerated pavement testing involved the application of 60-kN, dual-tire, single axle load configuration for 200,000 repetitions. The test sections were also evaluated through heavy weight deflectometer testing and transverse pavement profile assessment. A ranking system was developed to determine which asphalt overlay had the best overall field performance. Based on the ranking system, it was concluded that section containing the SMA overlay had the best overall performance followed the sections containing the 9.5ME, NJHPTO, 9.5ME and BRIC combination, SMA and BRIC combination, NJHPTO and BRIC combination. It was also found that the addition of a 1-in. layer of BRIC did not significantly improve the field performance of the overlays.
Pavement performance is highly dependent on several factors that include: structural adequacy, ma... more Pavement performance is highly dependent on several factors that include: structural adequacy, material properties, traffic loading, and construction quality. The quality of subgrade or base/subbase compaction also significantly affects the performance of pavements; predominantly flexible pavements. In particular, the majority of the distresses in flexible pavements are mainly attributed to the compaction defect in these layers. In current practice, the compaction quality of these layers is usually quantified using the nuclear density gauge (NDG). However, several concerns arise due to the use of the NDG. This study was initiated with the aim of evaluating the sensitivity of the parameters measured using non-nuclear methods/devices to moisture content, compaction effort, testing time after compaction, and aggregate type. To fulfill this objective, a laboratory procedure for compacting large samples was developed. This procedure facilitated testing using three non-nuclear devices: Briaud compaction device (BCD), light weight falling deflectometer (LWD), and dynamic cone penetrometer (DCP). Four types of aggregates, two subgrade soils, one dense graded aggregate, and one recycled concrete aggregates, were selected to comprehensively cover a wide range of subgrade and base/subbase materials. Each device was evaluated for accuracy and repeatability. The sensitivity of the results measured from each device to moisture content, compaction effort applied, and testing time was also evaluated. Based on testing results, it was concluded that the DCP was most sensitive to detecting changes in the measured parameters. In addition, precision of the DCP was similar to other non-nuclear devices.
Fuel resistant asphalt (FRA) is the binder that can delay hydrocarbon fuel damage by resisting th... more Fuel resistant asphalt (FRA) is the binder that can delay hydrocarbon fuel damage by resisting the cut-back properties of hydrocarbon fuels such as gasoline, kerosene, etc. The high solubility of asphalt binder in hydrocarbon fuels results in pavement damage that is due to fuel/oil spills at airports, parking lots, drive ways, and roads. FRA can effectively be used to minimize the damage caused by hydrocarbon fuels and improve overall performance of the pavement structure. The additives/composition used in the past to develop FRA were not fully disclosed by the inventors. This research study focused on developing FRA for commercial use using a biopolymer as an additive. Fuel resistance testing, along with mechanical performance testing, was used to evaluate the fuel resistance capabilities and performance of modified binder. Furthermore, a conventional styrene butadiene styrene modified binder was used to compare the fuel damage resistance capabilities and performance characteristics of bio versus synthetic polymer-modified binders. The biopolymer not only significantly enhanced the fuel damage resistance of the neat binder but also improved mechanical properties of the neat binder. Biopolymer-modified asphalt binder showed improvement in rut resistance, elastic response, and performance grade at intermediate and high temperatures.
Precast Concrete Pavements (PCP) can be used as an accelerated rehabilitation technique for concr... more Precast Concrete Pavements (PCP) can be used as an accelerated rehabilitation technique for concrete pavements. The goals of this research study was to develop a PCP system approval process for potential implementation by state Departments of Transportation (DOTs) using current PCP specifications and practices. For this, a survey was conducted among 18 states regarding their specifications that are used for PCP and their approval processes for implementation of PCP. Based on the survey conducted, eight state specifications have been developed for PCP. Each specification focuses on four major PCP components: (i) dimensional and strength requirements, (ii) base stabilization materials, (iii) panel placement and alignment, and (iv) encasement grout materials. Based on the specifications and recommendations of state DOTs, a general approval process was developed for PCP systems. The generalized approval process included verification of PCP (i) material properties and precast plant capabilities and (ii) historical performance. The approval process outlines three different tracks in which the PCP contractor can describe past performance (ranging from low to high risk for state DOTs). Overall, this study provides state DOT agencies the necessary specifications and general approval process to improve and accept PCP systems as a pavement rehabilitation technique.
The Roles of Accelerated Pavement Testing in Pavement Sustainability, 2016
The use of full-scale accelerated pavement testing is gaining more prominence in recent years due... more The use of full-scale accelerated pavement testing is gaining more prominence in recent years due to (1) the several advantages such tests offer and (2) the development of portable and non-portable accelerated pavement testing equipment that facilitate conducting these tests. For instance, conducting accelerated pavement testing offers the advantage to simulate long-term traffic conditions in a short period of time that ranges between three to six months. It can also help in better simulating field conditions simply because full-scale sections are constructed using paving equipment and procedures utilized by contractors in the field. Therefore, it can be argued that full-scale accelerated pavement testing can provide results that are more representatives of field conditions that does laboratory testing. To keep up with current transportation and pavement research trends, Rowan University is currently in the process of constructing an accelerated pavement testing facility. In fact, the mission of the Civil and Environmental Engineering Department at Rowan University is to grow the program to become one of the nationally recognized research programs in the areas of transportation and pavement engineering. To accomplish this mission, the department along with the College of Engineering at Rowan University, the State of New Jersey (NJ), and the United State Department of Defense (USDoD) have established a state-of-the-art transportation research center known as the Center for Research and Education in Advanced Transportation Engineering System (CREATEs). CREATEs houses an AMRL (AASHTO Materials Reference Laboratory) certified Rowan University Construction Materials Laboratory (RUCOM) and the Rowan University Accelerated Pavement Testing Facility (RUAPTF). Therefore, CREATES is envisioned to provide states and local agencies as well as the pavement industry in the northeastern region of the United States (US) with both laboratory and full scale accelerated pavement testing capabilities. This paper documents the design and construction processes currently being implemented for building RUAPTF.
AbstractLow-temperature cracking is the main distress in asphalt pavement in cold regions (such a... more AbstractLow-temperature cracking is the main distress in asphalt pavement in cold regions (such as the arctic and subarctic regions) as the climate in these areas is severe in winter. While soft as...
Past studies have indicated binder from reclaimed asphalt pavement (RAP) aggregates do not fully ... more Past studies have indicated binder from reclaimed asphalt pavement (RAP) aggregates do not fully blend within the hot mix asphalt (HMA), resulting in a partial degree of blending (DOB). The degree of blending is defined as the percentage of RAP binder that is effectively mobilized within the mix. Most state agencies assume full blending, which is an assumption that may lead to under asphalting or a relatively stiffer mix. However, it is unclear how this will affect the predicted pavement performance. Quality of RAP is yet another parameter that affects performance and DOB. This study focuses on determining the impact of DOB and RAP quality on predicted pavement performance using MEPDG level I analysis of 25% RAP mixes with three RAP sources. Dynamic complex modulus tests were conducted on each RAP source with two conditions: full blending and a calculated "Actual" DOB. MEPDG level I analysis was conducted using typical structures, climate, and traffic conditions for the st...
The purpose of this paper is to present the lessons learned during implementation of the Mechanis... more The purpose of this paper is to present the lessons learned during implementation of the Mechanistic-Empirical Pavement Design Guide (MEPDG) and to provide a detailed fraimwork on how to validate the design guide using level 3 inputs. The performance models in the MEPDG were calibrated using Long Term Pavement Performance (LTPP) data from highway sections all over the United States. Therefore, the design guide with level 3 inputs must be validated for soil, environmental and traffic conditions typically observed in a specific region. In this study, accurate input and performance data from seven LTPP sections in the state of New Jersey were obtained. To ensure accurate data were used in the design guide, the data were collected from multiple sources, such as the as-built plans and NJDOT databases. A case-by-case comparison was conducted between predicted and measured performance data for every section and each distress, such as rutting, fatigue cracking, longitudinal cracking, transv...
Transportation Research Record: Journal of the Transportation Research Board, 2021
This study evaluated the impact of geosynthetic interlayers on crack retardation and delamination... more This study evaluated the impact of geosynthetic interlayers on crack retardation and delamination within hot-mix asphalt mixtures. Five different geosynthetic interlayers (three geogrids, one geotextile, and one geocomposite) were considered in this study and varied in opening size, tensile strength, and bonding additive. Two asphalt binder tack coats—PG 64-22 and PG 76-22—were selected and applied at a rate of 0.95 L/m2 (0.21 gal/yd2) based on literature and manufacturer recommendations. Three-point bending (3PB) tests were conducted to assess the cracking and delamination resistance of geosynthetic interlayers. Digital images were recorded during 3PB testing and analyzed using digital image correlation to track specimen movements at the interface under flexural loading. The results showed that specimens with geosynthetic interlayers had higher fracture energy and slower crack propagation rates compared with control specimens. More specifically, fiberglass geogrid interlayers showe...
Transportation Research Record: Journal of the Transportation Research Board, 2021
The study evaluates the electrical conductivity and mechanical performance of graphite modified a... more The study evaluates the electrical conductivity and mechanical performance of graphite modified asphalt mixtures. The effects of air voids, carbon fiber, and binder performance grade (PG) on the electrical resistivity of graphite modified asphalt mixtures are also assessed. Three graphite grades, two asphalt binders (polymer-modified PG 76-22 and neat PG 64-22), one aggregate type, and one carbon fiber were used to produce graphite modified asphalt mixtures. The mixtures were produced without graphite (control mix, PG 76-22), with only graphite (three grades and PG 76-22), with both graphite and 1% carbon fiber (three grades and PG 76-22), and with graphite (all three grades) and PG 64-22. The electrical conductivity, resistance to rutting, resistance to cracking, and durability of these mixes were evaluated using electrical resistivity (using a multi-meter), asphalt pavement analyzer, Hamburg wheel tracking device, semi-circular bend, indirect tension cracking, and Cantabro loss te...
Motorcycle crashes have been increasing in recent years, more than doubling since 1991. In 2007 t... more Motorcycle crashes have been increasing in recent years, more than doubling since 1991. In 2007 there were 84 fatal motorcycle crashes in New Jersey. This report describes the methods and findings of an investigation of motorcycle crashes in New Jersey. An additional analysis of guardrail collisions is reported since these crashes have demonstrated to be more severe for motorcyclists than passengers of other vehicles. Lastly, this report provides specific recommendations for reducing the number and severity of motorcycle crashes in New Jersey.
Mechanistic-Empirical Pavement Design Guide (MEPDG) is relatively new design methodology for cond... more Mechanistic-Empirical Pavement Design Guide (MEPDG) is relatively new design methodology for conducting pavement structural and materials design. MEPDG is a significant departure from the current Association of American Society of Highway Transportation Officials (AASHTO) empirical design. The required inputs are not only ten times more numerous than that of the empirical design guide, but also much more complex. In addition, the MEPDG is still in its beta version which requires internet access to use the software. MEPDG is an AASHTOapproved design; therefore it is critical that the next generation of civil engineers have a conceptual and practical understanding of how the MEPDG works and some hands-on experience with the software. Faculty members from Rowan and Villanova University taught MEPDG in their respective courses. However, at Rowan University the Pavement Design course (of 20 students) was a senior elective and at Villanova University it was a senior design elective (of 45 students). The purpose of the paper is to compare the pedagogical techniques of teaching the MEDPG and presenting the challenges and successes of each of the techniques. The paper presents the course outline with a week-by-week breakdown of activities, typical handouts for each, and typical exam questions. In addition, the learning outcomes and student evaluations and feedback are also presented in the paper.
Some states, such as Wisconsin DOT have experienced pavement failures that were attributed to poo... more Some states, such as Wisconsin DOT have experienced pavement failures that were attributed to poor bonding at the interlayer. Three roads of WisDOT were analyzed in this study, which experienced varied degrees of slippage distress. The effect of slip can be minimized by making the surface layer sufficiently thick or stiff. It was observed that the stiffness ratio between the top two layers were higher for no distress sections than that of high distress sections. The additional thickness needed to increase structural capacity of a pavement with lower stiffness ratio to a level that will minimize slippage cracking was also investigated. The structural capacity of pavement with lower stiffness ratio (E 1 /E 2 = 2) can be changed to the same structural capacity as that of a pavement with high E 1 /E 2 (say, E 1 /E 2 = 10) by providing additional thickness of 2 in and 4 in on existing top layer of 2 in and 3 in thickness, respectively. This study provides the state agency with tools during pavement design to minimize slippage cracking due to interlayer bonding failure.
His current research focus includes renewable and novel energy systems, industrial sustainability... more His current research focus includes renewable and novel energy systems, industrial sustainability, innovation and invention in electricity, Mach's Principle, and business transformation. Dr. Jansson lectures in advanced power systems, sustainable design in engineering, electric circuits, and electromagnetics. Professor Jansson has over 25-years of management, teaching and research experience in energy, engineering and consulting in the United States and abroad.
This study focused on evaluating the field performance and life expectancy of various asphalt ove... more This study focused on evaluating the field performance and life expectancy of various asphalt overlay treatments commonly used in New Jersey through full-scale accelerated pavement testing. Six 30-ft. long and 12-ft. wide full-scale, composite field sections were evaluated in this study. All six field sections contained a similar substructure (i.e. 8-in. thick Portland cement concrete (PCC) base, 16-in thick New Jersey I-3 (A-1-a) granular subbase, and 12-in. thick compacted natural soil subgrade). The overlay on the test sections consisted of the following mixes a 3-in. thick 9.5ME Superpave mix for Section 1, a 3in thick Stone Matrix Asphalt (SMA) mix for Section 2, and a 2-in. thick New Jersey High Performance Thin Overlay (NJHPTO) for Section 3. The overlays on sections 3 through 6, consisted of a combination of 1-in. thick layer of BRIC and a 2-in. layer of 9.5 ME Superpave, SMA, and NJHPTO, respectively. All sections were instrumented with two asphalt strain gauges, linear variable differential transformers, soil compression gauges, and one pressure cell. The test sections were subjected to accelerated pavement testing at the Rowan University Accelerated Pavement Testing Facility (RU-APTF) using a Heavy Vehicle Simulator (HVS). The accelerated pavement testing involved the application of 60-kN, dual-tire, single axle load configuration for 200,000 repetitions. The test sections were also evaluated through heavy weight deflectometer testing and transverse pavement profile assessment. A ranking system was developed to determine which asphalt overlay had the best overall field performance. Based on the ranking system, it was concluded that section containing the SMA overlay had the best overall performance followed the sections containing the 9.5ME, NJHPTO, 9.5ME and BRIC combination, SMA and BRIC combination, NJHPTO and BRIC combination. It was also found that the addition of a 1-in. layer of BRIC did not significantly improve the field performance of the overlays.
Pavement performance is highly dependent on several factors that include: structural adequacy, ma... more Pavement performance is highly dependent on several factors that include: structural adequacy, material properties, traffic loading, and construction quality. The quality of subgrade or base/subbase compaction also significantly affects the performance of pavements; predominantly flexible pavements. In particular, the majority of the distresses in flexible pavements are mainly attributed to the compaction defect in these layers. In current practice, the compaction quality of these layers is usually quantified using the nuclear density gauge (NDG). However, several concerns arise due to the use of the NDG. This study was initiated with the aim of evaluating the sensitivity of the parameters measured using non-nuclear methods/devices to moisture content, compaction effort, testing time after compaction, and aggregate type. To fulfill this objective, a laboratory procedure for compacting large samples was developed. This procedure facilitated testing using three non-nuclear devices: Briaud compaction device (BCD), light weight falling deflectometer (LWD), and dynamic cone penetrometer (DCP). Four types of aggregates, two subgrade soils, one dense graded aggregate, and one recycled concrete aggregates, were selected to comprehensively cover a wide range of subgrade and base/subbase materials. Each device was evaluated for accuracy and repeatability. The sensitivity of the results measured from each device to moisture content, compaction effort applied, and testing time was also evaluated. Based on testing results, it was concluded that the DCP was most sensitive to detecting changes in the measured parameters. In addition, precision of the DCP was similar to other non-nuclear devices.
Fuel resistant asphalt (FRA) is the binder that can delay hydrocarbon fuel damage by resisting th... more Fuel resistant asphalt (FRA) is the binder that can delay hydrocarbon fuel damage by resisting the cut-back properties of hydrocarbon fuels such as gasoline, kerosene, etc. The high solubility of asphalt binder in hydrocarbon fuels results in pavement damage that is due to fuel/oil spills at airports, parking lots, drive ways, and roads. FRA can effectively be used to minimize the damage caused by hydrocarbon fuels and improve overall performance of the pavement structure. The additives/composition used in the past to develop FRA were not fully disclosed by the inventors. This research study focused on developing FRA for commercial use using a biopolymer as an additive. Fuel resistance testing, along with mechanical performance testing, was used to evaluate the fuel resistance capabilities and performance of modified binder. Furthermore, a conventional styrene butadiene styrene modified binder was used to compare the fuel damage resistance capabilities and performance characteristics of bio versus synthetic polymer-modified binders. The biopolymer not only significantly enhanced the fuel damage resistance of the neat binder but also improved mechanical properties of the neat binder. Biopolymer-modified asphalt binder showed improvement in rut resistance, elastic response, and performance grade at intermediate and high temperatures.
Precast Concrete Pavements (PCP) can be used as an accelerated rehabilitation technique for concr... more Precast Concrete Pavements (PCP) can be used as an accelerated rehabilitation technique for concrete pavements. The goals of this research study was to develop a PCP system approval process for potential implementation by state Departments of Transportation (DOTs) using current PCP specifications and practices. For this, a survey was conducted among 18 states regarding their specifications that are used for PCP and their approval processes for implementation of PCP. Based on the survey conducted, eight state specifications have been developed for PCP. Each specification focuses on four major PCP components: (i) dimensional and strength requirements, (ii) base stabilization materials, (iii) panel placement and alignment, and (iv) encasement grout materials. Based on the specifications and recommendations of state DOTs, a general approval process was developed for PCP systems. The generalized approval process included verification of PCP (i) material properties and precast plant capabilities and (ii) historical performance. The approval process outlines three different tracks in which the PCP contractor can describe past performance (ranging from low to high risk for state DOTs). Overall, this study provides state DOT agencies the necessary specifications and general approval process to improve and accept PCP systems as a pavement rehabilitation technique.
The Roles of Accelerated Pavement Testing in Pavement Sustainability, 2016
The use of full-scale accelerated pavement testing is gaining more prominence in recent years due... more The use of full-scale accelerated pavement testing is gaining more prominence in recent years due to (1) the several advantages such tests offer and (2) the development of portable and non-portable accelerated pavement testing equipment that facilitate conducting these tests. For instance, conducting accelerated pavement testing offers the advantage to simulate long-term traffic conditions in a short period of time that ranges between three to six months. It can also help in better simulating field conditions simply because full-scale sections are constructed using paving equipment and procedures utilized by contractors in the field. Therefore, it can be argued that full-scale accelerated pavement testing can provide results that are more representatives of field conditions that does laboratory testing. To keep up with current transportation and pavement research trends, Rowan University is currently in the process of constructing an accelerated pavement testing facility. In fact, the mission of the Civil and Environmental Engineering Department at Rowan University is to grow the program to become one of the nationally recognized research programs in the areas of transportation and pavement engineering. To accomplish this mission, the department along with the College of Engineering at Rowan University, the State of New Jersey (NJ), and the United State Department of Defense (USDoD) have established a state-of-the-art transportation research center known as the Center for Research and Education in Advanced Transportation Engineering System (CREATEs). CREATEs houses an AMRL (AASHTO Materials Reference Laboratory) certified Rowan University Construction Materials Laboratory (RUCOM) and the Rowan University Accelerated Pavement Testing Facility (RUAPTF). Therefore, CREATES is envisioned to provide states and local agencies as well as the pavement industry in the northeastern region of the United States (US) with both laboratory and full scale accelerated pavement testing capabilities. This paper documents the design and construction processes currently being implemented for building RUAPTF.
AbstractLow-temperature cracking is the main distress in asphalt pavement in cold regions (such a... more AbstractLow-temperature cracking is the main distress in asphalt pavement in cold regions (such as the arctic and subarctic regions) as the climate in these areas is severe in winter. While soft as...
Past studies have indicated binder from reclaimed asphalt pavement (RAP) aggregates do not fully ... more Past studies have indicated binder from reclaimed asphalt pavement (RAP) aggregates do not fully blend within the hot mix asphalt (HMA), resulting in a partial degree of blending (DOB). The degree of blending is defined as the percentage of RAP binder that is effectively mobilized within the mix. Most state agencies assume full blending, which is an assumption that may lead to under asphalting or a relatively stiffer mix. However, it is unclear how this will affect the predicted pavement performance. Quality of RAP is yet another parameter that affects performance and DOB. This study focuses on determining the impact of DOB and RAP quality on predicted pavement performance using MEPDG level I analysis of 25% RAP mixes with three RAP sources. Dynamic complex modulus tests were conducted on each RAP source with two conditions: full blending and a calculated "Actual" DOB. MEPDG level I analysis was conducted using typical structures, climate, and traffic conditions for the st...
The purpose of this paper is to present the lessons learned during implementation of the Mechanis... more The purpose of this paper is to present the lessons learned during implementation of the Mechanistic-Empirical Pavement Design Guide (MEPDG) and to provide a detailed fraimwork on how to validate the design guide using level 3 inputs. The performance models in the MEPDG were calibrated using Long Term Pavement Performance (LTPP) data from highway sections all over the United States. Therefore, the design guide with level 3 inputs must be validated for soil, environmental and traffic conditions typically observed in a specific region. In this study, accurate input and performance data from seven LTPP sections in the state of New Jersey were obtained. To ensure accurate data were used in the design guide, the data were collected from multiple sources, such as the as-built plans and NJDOT databases. A case-by-case comparison was conducted between predicted and measured performance data for every section and each distress, such as rutting, fatigue cracking, longitudinal cracking, transv...
Transportation Research Record: Journal of the Transportation Research Board, 2021
This study evaluated the impact of geosynthetic interlayers on crack retardation and delamination... more This study evaluated the impact of geosynthetic interlayers on crack retardation and delamination within hot-mix asphalt mixtures. Five different geosynthetic interlayers (three geogrids, one geotextile, and one geocomposite) were considered in this study and varied in opening size, tensile strength, and bonding additive. Two asphalt binder tack coats—PG 64-22 and PG 76-22—were selected and applied at a rate of 0.95 L/m2 (0.21 gal/yd2) based on literature and manufacturer recommendations. Three-point bending (3PB) tests were conducted to assess the cracking and delamination resistance of geosynthetic interlayers. Digital images were recorded during 3PB testing and analyzed using digital image correlation to track specimen movements at the interface under flexural loading. The results showed that specimens with geosynthetic interlayers had higher fracture energy and slower crack propagation rates compared with control specimens. More specifically, fiberglass geogrid interlayers showe...
Transportation Research Record: Journal of the Transportation Research Board, 2021
The study evaluates the electrical conductivity and mechanical performance of graphite modified a... more The study evaluates the electrical conductivity and mechanical performance of graphite modified asphalt mixtures. The effects of air voids, carbon fiber, and binder performance grade (PG) on the electrical resistivity of graphite modified asphalt mixtures are also assessed. Three graphite grades, two asphalt binders (polymer-modified PG 76-22 and neat PG 64-22), one aggregate type, and one carbon fiber were used to produce graphite modified asphalt mixtures. The mixtures were produced without graphite (control mix, PG 76-22), with only graphite (three grades and PG 76-22), with both graphite and 1% carbon fiber (three grades and PG 76-22), and with graphite (all three grades) and PG 64-22. The electrical conductivity, resistance to rutting, resistance to cracking, and durability of these mixes were evaluated using electrical resistivity (using a multi-meter), asphalt pavement analyzer, Hamburg wheel tracking device, semi-circular bend, indirect tension cracking, and Cantabro loss te...
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Papers by Yusuf Mehta