Damage evolution during freeze-thaw cycling of cement mortar, studied by electrical resistivity measurement

摘要

Damage evolution during freeze-thaw cycling of cement mortar was found by electrical resistivity measurement to involve damage accumulating gradually cycle by cycle until failure. The damage inflicted during cooling was more significant than that inflicted during heating. Damage infliction occurred smoothly throughout cooling from 52 to -20 deg C. Failure occurred at the coldest point of a temperature cycle. Electrical resistivity measurement allowed simultaneous monitoring of temperature and damage. An increase in temperature caused the resistivity to decrease reversibly, but with hysteresis, which grew with cycling. The effects of freezing and thawing on the resistivity were small compared to the effect of temperature on the resistivity.