THE RAPID-DETERMINATION OF THE MOISTURE-RETENTION CHARACTERISTICS OF SOIL

A modified technique is described for determining the water-retention curve of a soil. The new technique allows the definition of a moisture -retention curve (typically six to seven data points) much more rapidl y than is possible with conventional techniques such as the pressure p late apparatus. The full curve may be determined in four to six days c ompared with two to three weeks previously. Results are presented for three different soils. For one soil (a fly ash), comparative testing u sing the new technique and a conventional method shows good agreement. An added advantage of the new technique is that overall volume change of the soil specimen may be measured and not merely inferred from mea surements of moisture outflow. Greater accuracy in determining the moi sture-retention curve was thus obtained.