Effect of Partial Replacement with Crushed Concrete on Settlement and Bearing Capacity of Soft clay

Abstract

This paper aims to examine the effect of partial replacement with crushed concrete as a recycled material to enhance the bearing capacity and to decrease the settlement of soft clay. To clarify the effect of scale factor, four cubic steel soil tank with four dimensions of (250 x 250 x 250) mm; (300 x 300 x 300) mm;(400 x 400 x 400) mm; and (500 x 500 x 500) mm are used to carry out the experimental works, by using a foursizes for each square and strip footings with varying the depth of replacement (0.2, 0.4 and 0.6 width of square footing) and (0.33, 0.67 and 1 width of strip footing).The effect of replacement wasevaluated with regard to settlement control and bearing capacity. It is found from results of experimental works that a significant decreasing in settlement and increasing in bearing capacity of treated soil with increasing the depth of the partial replacement layer for both square and strip footing compared to untreated soil. The study also shows that the use of partial replacement layer with a depth of 0.4 B for strip footings results in reducing the settlements by an averaged percentage of 72 % and increasing the bearing capacity with an average of 96%. Also the results demonstrates that clear increasing in bearing capacity for all depth of replacement under square footing with indistinct in settlement