CREEP BEHAVIOR OF CEMENT-STABILIZED SOILS

The deformation characteristics of some cement-stabilized soils subjected to sustained compressive stresses and the influence of creep on the stress-strain behavior of the test soils were studied. The test specimens having 1.32-in. diameter by 3.00-in. height were prepared by using the static compaction method. Results of the study indicate, among other things, that the Burger model predicts reasonably well the deformation-time function, that the creep strain is nonlinearly proportional to the creep stress, that molding moisture content has no significant influence on the creep strain but increasing the cement content decreases considerably the creep strain, and that the creep strain increases with increasing clay content. Among the clay minerals studied, Na-montmorillonite exhibits the greatest creep strain. The cement-stabilized soils cured under isotropic pressure have a strength significantly lower than those cured under anisotropic pressure. Creep results in an increase in the strength and deformation modulus but decreases the failure strain. The percentage of change in the strength, modulus, and failure strain due to creep varies considerably with factors such as creep duration, stress level, molding moisture content, cement content, and clay content. The more active the clay, the greater the percentage of strength gain; however, no consistent result has been obtained for modulus gain and failure strain loss.