Effect of Creep Rate on Behavior of Clay-cement Soil Hanan Adnan Hassan Afaj


The time- dependent behavior of a clayey soil-cement was studied, using the triaxial compression test throughout the test programs under the unconsolidated undrained condition. The undrained condition represents the controlling drainage condition in which a creep failure may occur. The undrained creep behavior of soil-cement was investigated, using the following cement content (4, 8 and 12%), under three various stress-strength levels (60, 75and 85%). The creep time relation, effect of stress level on creep, effect of cement content on creep, creep rate, and the effect of creep on strength was studied thoroughly. Test results of 35 models showed that creep strain increases with the logarithm of time and stress level but decreases as the cement content increases. Also, increases in the strength and modulus of elasticity augment after creep but was affected by increases in cement content. On the other side, this research shows a particular stress level below which soil-cement sample will not fail; this is termed the critical stress level. Little increases in the critical stress level was indicated with increases in the cement content. Finally, linear relationship appears between logarithmic of creep rate and time, the slope of this relationship was found to be independent of stress level. Creep strain decrease rapidly with logarithmic of creep rate for specimens of 0% and 4% cement content while insignificant changes in creep properties occurred in specimens with 8% and 12% cement content.