Investigating the Statewide Variability and Long Term Strength Deformation Characteristics of RAP and RAP-Soil Mixtures: Phase 3: Draft Final Report; Draft final rept

摘要

Reclaimed Asphalt Pavement (RAP) usage is limited because tests on RAP and RAP-Soil blends indicates that creep may pose a concern and the statewide variability of RAP has not been addressed. RAP was blended with A-3 sands and the results showed that the addition of 20% A-3 improved the gradation, density, and bearing strength of RAP. Conventional highway materials testing were performed. The one-dimensional creep behavior of RAP and RAP-soil blends was evaluated. Axial strains were analyzed using Singh and Mitchell's approach. Using the resulting strain rate equations, settlements versus time predicted correctly characterized the material behavior. The soil in the RAP-soil blends effectively lowers the asphalt content. Blends containing less than 3.5% asphalt produced substantially lower strain and were not influenced by the applied stress level. The backfill settlements increased expontentially with increasing wall height. The exponential growth was faster at higher RAP contents. Most settlement was predicted to occur during construction. Horizontal and vertical creep and pullout characteristics of reinforcement embedded in 100% RAP, 50/50% RAP-sand blends and 100% A-3 were evaluated. The 100% RAP consistently produced the lowest pullout capacity of the steel reinforcing strips and the greatest reinforcing strip displacement of the three materials during pullout testing. The 50/50% blend yielded the greatest pullout capacity, however this blend yielded a greater strip creep displacement than the A-3. The 100% RAP yielded the largest vertical creep displacement followed by the 50/50% blend and A-3.