Pavement subgrade stabilization using polymers: Characterization and performance

This paper reports a laboratory investigation aimed at evaluating the potential of polymer binders to stabilize pavement subgrades in Qatar. The conclusions regarding the impact of the polymer stabilizers are based on comparisons with selected physical, chemical, mechanical, and microstructural properties of natural Qatari subgrade soil and soils stabilized with the traditional standard, portland cement (PC). The results demonstrate that the polymer binders modify the Qatari subgrade soils resulting in more favorable engineering properties: for example, the compressive strengths of the polymer-stabilized soils are superior to those of the unstabilized soils and those stabilized using PC. The mechanical properties of the stabilized and unstabilized soils were incorporated in the analysis of asphalt pavement sections using the state-of-the-art protocol for pavement design and analysis. Results of the analysis further demonstrated the benefits of using stabilizedsubgrade soils in improving pavement performance. Of particular practical importance is that polymer subgrade stabilization significantly reduces subgrade rutting. Consequently, polymer subgrade stabilization is a key consideration for perpetual pavements, especiallyconsidering the extremely high truck traffic in Qatar. Although the work reported in thispaper was carried out with Qatari soil, the results are expected to be relevant to other types of soil and weather conditions experienced throughout the Middle East and in similar climates throughout the world.