Apparatus and Tests for Determining Negative Pore Water Pressure Characteristics of Desiccated Clays

摘要

A study was conducted to evaluate the influence of negative pore water pressure development in expansive desiccated clays on building behavior. The report describes the apparatus and procedures for the determination of negative pore water pressure characteristics of dessicated clays. Three trials on specimens plus auxiliary tests were conducted on samples from a test site at Lackland AFB. A water content decrease from 28.5 to 25.5 percent was noted as the negative pore water pressure increased from 0 to 20 atm. The permeability of concrete suggested that foundation piers in some soils may act as wicks, conducting water downward beyond the inverted capillary fringe and zone of fissures.