Ranking of Four Chemical and Mechanical Stabilization Methods to Treat Low-Volume Road Subgrades in Texas

摘要

Expansive soils encountered in North Texas exhibit low strength properties, as well as high swell and shrinkage characteristics. These soil properties often result in the poor performance of pavement infrastructures, particularly those built for low-volume traffic conditions. Pavement distress caused by differential heaving leads to pavement cracking and ponding problems. This causes riding discomfort for commuters and induces traffic delays due to the continual repair of the pavements. Hence, it is necessary to explore and develop new and alternate stabilization methods to improve stabilization of expansive soils. Laboratory investigations were designed and conducted on four local expansive soils stabilized with low-calcium Class F fly ash, Type V sulfate-resistant cement, ground granulated blast furnace slag (GGBFS), and lime mixed with fibers. Test results were analyzed and ranked by well-established scales to select the top-performing stabilizers. Results showed that the sulfate-resistant cement, followed by the lime with fibers and the GGBFS stabilization methods, provided effective stabilization of soft and expansive soils. Ranking assessments were performed, and a few important conclusions on stabilization mechanisms were drawn.