Pressure Stimulated Current Emissions on Cement Paste Samples under Repetitive Stepwise Compressional Loadings

摘要

The electric signals detection technique that is described here was applied on several geomaterials in the past and on cement based materials lately. In this work cement paste samples were studied regarding electric signal emissions during axial stress application processes and specifically when the samples were subjected to repetitive loadings and unloadings in the range where crack opening and propagation processes are established. It was observed that the electric signal was emitted in two stages. Initially, current was emitted simultaneously with the stress step in the form of a spike which gradually returned to its background level. A secondary current emission was recorded while the stress was maintained constant at the high level of each stress step.