COMPREHENSIVE APPROACH FOR SWELLING SOILS REMEDIES

Abstract

The effect of drying and remolding on undisturbed expansive soil samples were investigated at different periods. The results showed that the swelling potentials for remolded samples were higher than those for undisturbed samples for different periods of testing. The results also showed that final swells and swell pressures increased as the initial moisture contents decrease for both remolded and undisturbed samples. The swelling potential increased as the initial dry density increases for both remolded and undisturbed expansive soil samples, and vice versa The cement dust used as a new additive material to decrease the swelling potential of the expansive soil. The results showed that the plasticity index, linear shrinkage, and clay minerals decreased with increasing cement dust percentage, where 50% of the montmorillonite disappeared after treatment the soil with 5% cement dust. The effect of cement dust columns on the swelling potential of the soil also studied extensively. The cement dust columns were embedded in the middle of the expansive soils using CBR mould .The results showed that the swelling potential decreased with increasing number of cement dust columns and when increasing the diameter of the cement dust columns ,a distinctive decrease in the swelling potentials were recorded. When decreasing the densities and increasing the diameters of cement dust columns resulted in decreasing the swelling potentials of the expansive soil. The swelling of the expansive soil been decreased when increasing the number of reinforced and non-reinforced cement dust columns. The swelling potentials showed distinctive decrease when the lengths of the reinforced cement dust columns increased.