Soil-Cement Bases under Thin Bituminous Surfacing

The deformation properties of soil-cement bases, in particular bases under thin bituminous surfacing, are investigated under repeated dynamic compressive loading. Tests were carried out on 4-in. x 2-in. diam. compacted samples in a modified triaxial cell. Load and deformation measurements were done electronically and recorded automatically in an ultraviolet unit. Results covered in this paper are for samples prepared at their optimum moisture contents and tested at a constant rate of compression of 10 cm/min. The principal variables considered here are stress intensity and frequency, and cement content. Analyses of the compressive strength, Poisson's ratio and modulus of resilient deformation, show that soil-cement bases can be confidently employed under thin bituminous surfacing within stated limitations of minimum critical strength and maximum resilient deformation.