Injection of fine sands with very fine cement grout

The use of very fine cement grouts for injection into fine to medium sands has been proposed recently 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. The results of a laboratory investigation conducted on a commercially available very fine cement grout indicate that this grout has better flow properties and bleed characteristics than ordinary portland cement grouts. Very fine cement grouts with a water-to-cement ratio as low as two can permeate several feet into well-compacted fine sands with D₁₅in the range of 0.15 mm. The groutability ratio is not a universally applicable criterion, and experimental evidence suggests that the grain-size distribution of the fine sand, and especially the amount of fines in the sand, may control the grouting operation. The granulometry of the fine sand influences the effectiveness of the grouting operation in terms of permeability and strength.