1.Soak specimen in warm after a specified time then observe whether specimen surface had degenerative conditions as blister,fadeaway,swell.…etc.to judge its quality and calculate the change rate of weight before/after test.
2.and the swell is a power function or a logarithm function of time,deponding on the slope of line ～t . The theoretical results are verified by the test results of Ningxia expansive soil.
