Strength Variance within Cement Treated Soils Induced by Newly Developed Pneumatic Flow Mixing Method

In the study, field and laboratory tests were conducted to investigate the degree of strength variance within cement treated soils. The cement treated soils were the dredged soils mixed with a small amount of cement. They were produced by Pneumatic Flow Mixing Method, which had been recently developed in Japan. In the paper at first the outline of Pneumatic Flow Mixing Method system is presented. Then several backgrounds causing the strength variance within the cement treated soils are described. It is found that the cement-water ratio of treated soils was stable, which was monitored and controlled during their production. The effect of mixing adequacy of the soil-cement mixture and that of non-homogeneity of dredged soils on the strength variance is also discussed. Finally the effective measure to reduce the strength variance is described.