Effect of calcium chloride and kaolinite on shear strength and shrinkage of cement grout

Abstract

Grouting is injecting a liquid (cement and additives) into voids within a structure or soft soils for displacing the gases and liquids from within these. The varieties of additives for different grouting purposes are using with cement. Calcium chloride is known as accelerator in the grout, it causes to decrease the set time of grout and it has a minor effect on fresh grout properties. Kaolinite or some other fine mineral soils are used as filler in the grout to get cost-effective grout. In this study, the different effects of calcium chloride and kaolinite were investigated on shear strength of soil treated by cement grout, and shrinkage of the grout. Samples were prepared by mixing specific amounts of cement, water, and organic soil with different ratios of calcium chloride and kaolinite. Unconfined compressive strength (UCS) of the soil treated was evaluated after curing for 3 and 30 days and the linear shrinkage of each grout were measured after 30 days. The results indicated that, kaolinite has positive effect on shear strength of soil treated and shrinkage of the cement grout. By increasing kaolinite, the shear strength of samples increased and the shrinkage of grout decreased respectively. On the other hand, calcium chloride seemed to have different effects on the shear strength of samples and shrinkage of grout. It did no’t have tangible effect on shrinkage of the grout except in the grout with 1% calcium chloride. Key words: Grouting, kaolinite, calcium chloride, cementation, pozzolanic reactions.