LABORATORY STUDY OF THE EFFECTIVENESS OF CEMENT AND OF LIME STABILIZATION FOR EROSION CONTROL

Soils ranging in texture from sand to heavy clay can be rendered effectively resistant to the soil erosion caused by raindrop impact by treatment with as little as 1 percent portland cement or hydrated lime. Erosion resistance was evaluated in a standard rainstorm sequence in which 8.2 cm (3.25in) of rain was applied for 1 h on each of two successive days. Compacted but otherwise unstabilized soils lost 1 to 2.5 g/sq m (0.014 to 0.035 lb/in.) of exposed surface, equivalent to 45 to 110 tons/acre, in this standard test. Incorporation of stabilizer and appropriate curing before exposure decreased this erosion loss to about 0.11 b/sq m (0.0016 lb/in.), equivalent to 5 tons/acre, for fully compacted specimens. Cement-treated soils tested after only modest compaction maintained their erosion resistance, but lime-treated soils were adversely affected by reduced levels of compaction. These laboratory test results do not necessarily predict practical field performance, because the effects of running water erosion, of the incomplete mixing characteristic of field incorporation of stabilizers, and of cycles of temperature change, wetting and drying, and freezing and thawing have not been tested.