Effect of Cement Fineness on the Penetrability of CEM IV/B Based Cement Grouts

Abstract

Grouting is a common technical method with many applications, e.g. it is used for soil stabilization and strengthening, for reduction for water ingress to underground facilities or of the water loss through a dam foundation, etc. Grouts comprise several constituents, which are combined in many ways depending on the in-situ conditions and the outcome desired. The use of very fine cement grouts for injections into fine-to-medium sands has been proposed to circumvent problems associated with the permanence and toxicity of chemical grouts and the inability of ordinary cement grouts to permeate soil formations finer than coarse sand. A laboratory investigation was conducted in order to evaluate the penetrability of cement suspensions. Four gradations from CEM IV/B (according to EN 197-1) type of cement were used having nominal maximum grain sizes of 100 μm, 40 μm, 20 μm and 10 μm. Suspension properties with water-to-cement (W/C) ratios of 1:1, 2:1 and 3:1 by weight, were determined in terms of apparent viscosity. Penetrability was evaluated by conducting one-dimensional injections into four different, clean sands using a specially constructed device. Penetrability of cement suspensions increases with increasing cement fineness and water-to-cement (W/C) ratio. Microfine cement suspensions with water-to-cement (W/C) ratios of 2:1 and 3:1 can penetrate into medium-to-fine sands.