Investigation of Various Pavement Repairs in Low-Volume Roads over Expansive Soil

Abstract

Expansive soil is one of the most common causes of pavement distress. Expansive soils undergo changes in volume due to moisture fluctuations from seasonal variations. These changes are reflected in the stability and performance of pavement layers. The objective of this research is to evaluate existing repair projects on selected farm-to-market (FM) roadways. Those roadways experienced failures in the form of fatigue and rutting along the wheel path, and longitudinal (faulted) cracking, including edge cracking. Those failures are due to high-plasticity expansive soil and narrow pavement lanes. This research study implemented visual survey, field and laboratory testing, ground penetrating radar (GPR) scanning, and structural design evaluations for three project sites to evaluate existing pavement treatment options. Using up to 14 years of performance records, this study suggested that geogrid reinforcement combined with lime-treatment is an effective repair at areas with low to moderate plasticity soil. Also, cement-treated base is found to be an effective treatment option in areas with high-plasticity expansive soil.