A case study of pavement failures in Central Texas due to expansive soils
The volumetric strains induced in the subgrade of a pavement or light foundation by the swelling and shrinking of expansive soils routinely cause distress, and ultimately failure of the structure. Additionally, shallow embankment slope failures have also been shown to cause damage to pavements throughout Central Texas. As such, the main objective of this project was to correlate observed field pavement distresses, attributed to expansive soil movement, to results obtained from laboratory forced ventilated swell-shrink tests. Additionally, the author wished to analyze if edge distresses could be attributed to shallow slope stability failures. This research was conducted with the cooperation of the Capital Area Pavement Engineering Council (CAPEC); a multi-agency entity with the goal of mitigating or eliminating historical pavement distresses with roadways constructed over highly expansive soils. Forced ventilated swell-shrink tests were conducted on specimens from six specific test section locations. In general, the magnitude of shrinkage strains measured in the laboratory were larger for specimens obtained from severely distressed roadway sections.