A case study of the comparison between rubberized and polymer modified asphalt on heavy traffic pavement in wet and freeze environment

Ground tire rubber (GTR) usage in asphalt pavement with the dry process has gained more prominence in recent times. The objective of this work is to investigate the pavement performance of GTR-modified asphalt pavement and polymer-modified asphalt pavement on heavy volume of traffic conditions in Michigan\u27s wet and freeze environment. A suite of laboratory tests was done to evaluate the pavement performance of GTR-modified and polymer-modified asphalt mixtures. To reveal the strain and stress relationship under different frequencies and temperatures, the dynamic modulus test was applied. The Hamburg wheel tracking device (HWTD) was used to assess the high-temperature deformation resistance. The disc-shaped compact tension (DCT) test was used to evaluate the low-temperature cracking characteristics. The characteristics of the asphalt binder were assessed by the dynamic shear rheometer (DSR) for high-temperature properties and the asphalt binder cracking device (ABCD) for low-temperature properties. After the construction, a field noise test was conducted. The experimental results stated that the polymer-modified asphalt mixture and GTR-modified asphalt mixture showed higher dynamic modulus and better ability to prevent cracking than the conventional asphalt mixture at low temperatures, as well as better permanent deformation and stripping resistance than the conventional asphalt mixture. The fracture energy of the GTR-modified hot mix asphalt (HMA) is 13–16 % larger than the polymer-modified HMA. The number of passes to the stripping point of GTR-modified was 510–518 % higher than the conventional HMA. When compared to the field core, the lab-compacted HMA offers superior pavement performance. The extracted asphalt binder test results show the GTR-modified asphalt has better rutting resistance and cracking resistance than polymer-modified asphalt, and the results in the noise test demonstrated that the rubber-modified asphalt pavement mitigated the noise level by 2–3 dB on the road at different vehicle speeds. Moreover, the pavement condition was noticeably enhanced after the reconstruction of the surface course. The total number of passenger tires to be used in this project is about 2270. To summarize, better rutting and cracking properties in asphalt pavement are shown by the project\u27s utilization of rubber technology. And the GTR-modified HMA is comparable to polymer-modified HMA. Therefore, it may be appropriate to utilize rubber technology on high-traffic volume asphalt pavement in Michigan\u27s wet and freeze climate

Assessment of Long-term Performance of Pavements Containing Warm Mix Asphalt Technologies in Louisiana

This study focused on the assessment of long-term performance of asphalt pavements containing warm mix asphalt technologies in Louisiana. A total of five rehabilitation projects were studied in the state of Louisiana. The study consisted of engineering desk analyses of field performance indicators, indices and the initial laboratory performance indicators measured for five rehabilitation projects. The engineering desk study consisted of a review of literature from previous WMA technology projects done in Louisiana. Additionally, data was acquired and validated from the Louisiana Pavement Management System (PMS). Pavement performance indicators (i.e., cracking (transverse, longitudinal, and fatigue cracking), roughness, rutting, and pavement indices and pavement condition index data acquired from PMS were analyzed using statistical methods. Furthermore, laboratory test data for mechanical performance indicators at the construction stage such as loaded wheel tracking (LWT) rut depth, semi-circular bend (SCB) Jc , flow number, and dissipated creep strain energy (DCSE) were obtained from LTRC database and published reports. Analysis to link initial laboratory mechanical performance indicators to field performance indicators were performed. In general, similar, or better pavement performance indicators for rutting and cracking (longitudinal, transverse, and alligator) was reported for WMA test sections compared to their companion hot mix asphalt (HMA) sections. Additionally, the LWT rut depth was found to be a better indicator of field rutting performance than the flow number parameter. It should be noted that SCB Jc parameter was found to correctly rank more field cracking indicators than the DCSE parameter and hence may be a better indicator of field cracking performance than the DCSE parameter. Additionally, the actual field performance indices for both Conventional HMA AND WMA test sections were similar or higher than the predicted indices based on LA DOTD performance curve formulae. Which indicates a better or similar distress performance after seven to ten years in service

Comparison of Rubber Asphalt with Polymer Asphalt under Long-Term Aging Conditions in Michigan

The objective of this study is to compare the long-term aging performance of dry-processed rubber-modified asphalt mixture with styrene–butadiene–styrene polymer-modified asphalt mixture on heavy traffic volume roads in the wet-freeze environment of Michigan. The rutting performance was evaluated using the Hamburg wheel track device. The disc-shaped compact tension test was used to assess the fracture energy. The dynamic modulus experiment was used to estimate the load and displacement relationship. The asphalt binder properties were evaluated using multiple stress creep recovery and the linear amplitude sweep test. The pavement distresses were evaluated using the pavement mechanistic–empirical design. All three types of asphalt mixture show excellent rutting resistance after long-term aging conditions, while the fracture energy of the rubber mix is 17.1% to 30.5% higher than that of the control mix and 6.8% to 9.1% higher than that of the polymer mix. The rubber and polymer incorporated with the asphalt binder improved the resistance to permanent deformation and improved the fatigue life of the asphalt binder. In summary, the rubberized asphalt technology using the dry process shows better cracking resistance and fatigue life. Therefore, rubberized asphalt using the dry process will exhibit adequate performance when used for high-volume roads in the wet-freeze environment of Michigan