Variability Of The Moisture Sensitivity Of Field HMA Mixes

The objective of this study is to evaluate the variability in moisture sensitivity of lime treated HMA mixes that were sampled during construction from three projects located in the Truckee Meadows region

Laboratory Evaluation of Thin Asphalt Concrete Overlays for Pavement Preservation

A significant percentage of the existing lane miles of roadways in the United States, and in particular in Nevada, consists of rural roads. Thus, using a cost-effective pavement surface treatment becomes critical and essential in reducing maintenance and preservation costs on rural and low volume roads. The overall objective of this study was to assess the use of locally available materials in Nevada for the development of a durable fine-graded thin hot-mix asphalt (HMA) overlay mixture for pavement preservation. Accordingly, a comprehensive laboratory evaluation was conducted. The investigation considered establishing two mix designs using typical local materials for the northern and southern part of the state. For each mixture, the determined optimal binder content based on volumetric properties was varied within the allowable tolerances to simulate the potential variation in asphalt binder content during plant production. The performance of the two thin HMA mixtures were then evaluated at the various asphalt binder contents in terms of their resistance to moisture damage, resistance to surface raveling and abrasion, dynamic modulus property, resistance to rutting, and resistance to reflective cracking. Furthermore, the workability of the designed thin HMA overlay mixtures using the locking point concept in addition to the developed interlayer bond strength using the Louisiana Interlayer Shear Strength Tester were evaluated. Overall, both designed fine-graded mixtures showed a very good performance and are expected to perform well when used as a thin HMA overlay in Nevada. In particular, good stability, very good resistance to surface raveling and abrasion, and excellent resistance to reflective cracking were observed for both thin HMA overlay mixtures at all evaluated asphalt binder contents. A cost analysis was also conducted between the thin HMA overlay and a typically used pavement surface treatment. Based on the findings from this study, it was recommended to construct field test sections in various parts of the state to evaluate the field performance of the developed thin HMA overlay mixtures in Nevada

Use Of Reclaimed Asphalt Pavements (RAP) In Airfields HMA Pavements

This report documents the results and findings of the AAPTP Project No. 05-06: Use of Reclaimed Asphalt Pavements (RAP) in Airfields HMA Pavements. The report includes a review of current technology in RAP pavements and its application in highway and airfield pavements. Additionally, the report includes the current highway specifications on the use of RAP and a mechanistically based method to transfer the RAP technology that has been successfully used on highway pavements into the design and specification systems for RAP on airport pavements. Review of in-service airfield pavements was conducted as part of this study. Furthermore, the report includes an evaluation of the impact of RAP on the performance life of HMA airfield pavements under three actual airport traffic mixes of a large hub, small hub, and general aviation. The Life cycle cost analysis used the characteristics and mechanical properties of HMA mixtures in the LEDFAA1.3 airfield pavement design software to compare the estimated performance life of HMA pavements with and without RAP materials. Finally, sections 401-3.3 and 403-3.3 of FAA’s P-401 and P-403 specifications, respectively, on RAP were reviewed and recommendations were made based on the findings of the research effort conducted in this project

Development Of Specifications For Engineered Cementitious Composites For Use In Bridge Deck Overlays

Engineered cementitious composite (ECC) material is a high strength, fiber-reinforced, ductile mortar mixture that can exhibit tensile strains of up to 5%. ECC has a dense matrix, giving the material exceptional durability characteristics. The durability and mechanical properties of ECC make it a desirable, though expensive, construction material. This study presents an extensive evaluation of modified engineered cementitious composite (MECC) using locally sourced raw materials for use as a bridge deck overlay material. MECC is a mixture of cement, fly ash, water, concrete sand, and poly-vinyl alcohol fibers. The concrete sand used in this study was used in lieu of the typically used silica sand to reduce the high material cost for ECC. Three different representative aggregates from throughout Nevada were selected to understand how the local aggregates would perform in MECC mixes. In total, eighteen different laboratory mixes of MECC were evaluated using multiple performance and mechanical tests. After the completion of the laboratory phase, two different field trials were conducted to determine the feasibility of batching large amounts of MECC at commercial concrete batch plants. Based on the results of the laboratory evaluation, large-scale trial batc

Case Studies on the Implementation of Balanced Mix Design and Performance Tests for Asphalt Mixtures: New Jersey Department of Transportation (NJDOT)

The primary objective of this overall effort was to identify and put forth positive practices used by SHAs when implementing BMD and performance testing of asphalt mixtures. To accomplish this objective, information was collected through site visits and other means with seven key agencies. New Jersey Department of Transportation (NJDOT) graciously agreed to host a virtual site visit

Case Studies on the Implementation of Balanced Mix Design and Performance Tests for Asphalt Mixtures: Louisiana Department of Transportation & Development (LaDOTD)

The primary objective of this overall effort was to identify and put forth positive practices used by SHAs when implementing BMD and performance testing of asphalt mixtures. To accomplish this objective, information was collected through site visits and other means with seven key agencies. Louisiana Department of Transportation and Development (LaDOTD) graciously agreed to host a virtual site visit

Laboratory Evaluation Of HMA Mixes Manufactured With Pg64-28nv And Pg64-28pm Polymer-modified Asphalt Binders

The purpose of this study was to evaluate and compare the mechanical properties of asphalt mixtures manufactured with PG64-28PM to those manufactured with PG64-28NV. Additionally, a mechanistic-empirical analysis was conducted to evaluate the impact of the two polymer-modified HMA mixtures on predicted pavement performance

Pavement Design and Materials Research 2003-2005 Activities

This report documents the workthat has been completed under the NDOT-UNR cooperative agreement for Pavement Design and Materials Research for the 2003-2005 time period

Positive Practices, Lessons Learned, and Challenges When Implementing Balanced Design of Asphalt Mixtures: Site Visits

Virtual site visits and interviews of seven key State Departments of Transportation (DOTs), along with material producers, consultants and paving contractors that serviced the agencies were conducted to learn more regarding the details of Balanced Mix Design (BMD) and performance tests implementation efforts. Successful practices documented from these virtual site visits were collected and synthesized into an overall process of implementing BMD as part of mix design approval and quality assurance (QA). This process comprises eight major tasks that are meant to present and summarize the activities that a State DOT may need to undertake to implement a BMD program depending on its organizational structure, staffing level, workspace, annual asphalt tonnage, as well as industry experiences and practices. Examples of positive practices, lessons learned, and challenges from States for the various tasks are presented. A list of research and deployment topics identified during the virtual site visits are also summarized

Case Studies on the Implementation of Balanced Mix Design and Performance Tests for Asphalt Mixtures: Maine Department of Transportation (MaineDOT)

The primary objective of this overall effort was to identify and put forth positive practices used by SHAs when implementing BMD and performance testing of asphalt mixtures. To accomplish this objective, information was collected through site visits and other means with seven key agencies. Maine Department of Transportation (MaineDOT) graciously agreed to host a virtual site visit