Determination of cement content of grouted sandy soils

Abstract

Grout injection in soils and rocks constitutes a method widely used in civil engineering. In the case of soils, the main results expected from the injection treatment are either a reduction in permeability or an increase in mechanical characteristics, or sometimes, both improvements are looked for. The flow of grouts in the pore space of the soil or any discontinuity of rock is resisted by the drag at the interface between the grains and the fluid. For soils that are not uniformly graded, useful estimates of the grout penetrated to the soils are required. Generally the monitoring and efficiency of grouting is observed by the flow - rate versus pressure which depends upon the porosity of the soil to be grouted. The efficiency of grouting mainly depends upon the penetration of cement grout through the pores of sand. Therefore cement content determination is very much necessary to assess the quantity of lateral flow of the grout into the soil mass. Samples from different depths and from different radial distances were cut from this grouted mass for the determination of cement content. The results clearly indicated that the grouting efficiency in the case of cement grouted beds can be ascertained by determination of cement content at different distances from the centre of grout hole.