Performance of Various Pavement Repairs in Low-Volume Roadways over Expansive Soil

Expansive soil is considered one of the most common causes of pavement distresses. Depending upon the moisture level, expansive soils will experience changes in volume due to moisture fluctuations from seasonal variations. The objective of this research was to evaluate existing repair projects on selected roadways. Those roadways experienced failures in the form of fatigue and rutting in the wheel path, and longitudinal (faulted) cracking including edge cracking. The causes of those failures were mainly linked to high plasticity expansive soil and narrow pavement. The study involved visual survey, field and laboratory testing, surface condition/ride data and structural design calculations for three project sites. The study concluded, from 3-14 years of performance records, that geogrid reinforcement, lime-treated subgrade and cement-treated base were found to be effective treatment options for low-volume roadways where high plasticity expansive soil exists.