Performance of Full-Scale Test Section of Low-Volume Road with Reinforcing Base Layer of Soil-Lime

The roads of the rice region of Merin Lake in Uruguay are subjected to low annual average traffic. However, the average daily traffic is approximately 100 trucks during harvest time. The local soils, characterized as clayey silts, are unsuitable for such traffic demands and are generally replaced or reinforced by materials found more than 70 km away, with high transportation costs. An investigation of the performance of a full-scale test section of pavement with a base layer of local silty clay soil stabilized with lime was conducted. The design of the test section consisted of soil selection, determination of lime content for stabilization, compaction, and California bearing ratio laboratory tests. Two test sections, each 50 m, were built, with a base layer of selected soil mixed with 3% lime in one section and with 5% lime in the other. After the rice harvest, the performance of the test sections was evaluated by visual observation of the base layer and deflection measures with a Benkelman beam. Despite some construction difficulties, the deflection average values changed from 244 X 10(-2) cm immediately after the section was built to 77 x 10(-2) cm 4 months later. The use of soil lime material for base layers of low-volume roads is a technical and economical alternative that provides a significant improvement of the rural road network with socioeconomic benefits.