Performance of Novel Chemical Grout in Treating Sands

Abstract

A new chemical grouting formed by sodium silicate-boric acid mixtures was introduced. Initially, suitable sodium silicate and boric acid contents in the grout mixtures were studied. Gel time, initial viscosity, and syneresis properties of adopted grouts were determined. Strength and permeability of grouted sand specimens having different gradation, relative density, curing time, and condition were investigated. Gel time decreased but viscosity increased as the sodium silicate and boric acid contents increased. Syneresis of grouts increased with the increase in sodium silicate and boric acid contents. As the silicate content of the grout solutions increased, the unconfined compressive strengths of the wet-cured and air-dried specimens increased, but decreased with time as a result of syneresis. The permeability of the wet-cured sand specimens decreased by two to three orders of magnitude after grouting; it increased with increasing silicate content but decreased with increasing in boric acid content. (C) 2017 American Society of Civil Engineers.