Abstract

This article describes two general methods to impart desired water control and physical and mechanical properties to soil profiles by chemical treatments. Chemical grouting is the practice of injecting liquids (chemical grouts) containing organics and/or inorganics that solidify to form strong, water-impermeable barriers into soil, rock, or concrete. Organic systems containing monomers that can polymerize or soluble polymers that can cross-link into insoluble gels are most often used grouts. Grouts comprising polyacrylamides and polyurethanes are in common use. Typical applications include construction and repair of buildings, dams, shafts, etc. Chemical soil conditioning is the use of chemical treatments, typically with polymers, to improve the ability of soils to support vegetative growth in large-scale agriculture, horticulture, and urban applications. Some soil conditioners help create and/or stabilize larger soil aggregates, reducing erosion and improving the efficiency of irrigation water use. Others are used to provide water reservoirs in the soil to facilitate agriculture in drier locations. Still others coat and stabilize soil surfaces against wind and water erosion. Many soil conditioners are similar to the polymeric systems formed in situ by chemical grouts. The most commonly used soil conditioners are acrylic polymers, especially copolymers of acrylamide and sodium acrylate.