Comprehensive Field Studies to Address the Performance of Stabilized Expansive Clays

Abstract

This work was conducted as part of a research study for the City of Arlington, Texas, to explore and develop alternative stabilization methods for sulfate-rich soils located in southern parts of the city. As a result of a literature review of sulfate-rich expansive soil treatments and comprehensive laboratory studies, four stabilizers were recommended for field treatment studies: sulfate-resistant cement (Type V), low-calcium Class F fly ash with Type V cement, ground granulated blast furnace slag, and lime mixed with polypropylene fibers. The four stabilizers, along with control lime treatment, were used to modify subsoil near Harwood Road in South Arlington. Rigid pavements were then constructed on the stabilizers' sections, and these sections were instrumented with strain gauges and pressure cells. Pavement instrumentation was then monitored to address load transfer mechanisms and stabilized materials' compression behavior under traffic loads. Elevation surveys were also conducted to evaluate swell movements of the treated subsoils. X-ray diffraction analyses were conducted on treated subgrade specimens to address the formation of ettringite mineral. On the basis of these evaluations, the performance of the four stabilization methods was compared with that of the control lime section.