Basic Factors Controlling Strength and Deformation Characteristics of Cement-Mixed Gravel

A series of consolidated drained (CD) triaxial compression (TC) tests were performed on unsaturated specimens of cement-mixed gravel compacted at different values of water content (W_i) and cement/gravel ratio by weight (c/g). It is shown that, even for a fixed dry density, ρ_d, the compressive strength, q_max exhibits a clear peak when compacted at W_i = "W_opt for a given compaction energy". The value of q_max and pre-peak stiffness increases significantly with and increase in ρ_d associated with an increase in the compaction energy not only for a fixed c/g but also for a fixed ratio of cement weight to specimen volume (c/V_t). Moreover, the effect of c/g on q_max becomes more important for higher densities. It is suggested, to attain a high strength of cement-mixed soil, high compaction is one of the most important key factors while the water content (W_i) at compaction should be controlled to be close to the respective W_opt for given compaction energy.