Strategy for In-Situ Determination of Autogenous Self Healing Capacity Through Limited Measurements

摘要

A new strategy is presented in this paper for in-situ measurement of the healing effect without pre-knowledge of the environmental condition. Exploiting the fact that the electrical conductivity in the crack is lower than that of undamaged section, the effective macroscopic cracking effect is first distinguished by frequency dependent impedance measurements both along (parallel to) and across the cracks. Dielectric spectroscopy along the cracks is found to correlate well with gravimetric measurements and can therefore be used for inverse approximation of moisture content. The effect of moisture change on the equivalent resistance in the direction across the cracks can then be derived approximately from measurements under various moisture contents. The approximated resistance vs moisture curve is found to reflect the evolution of autogenous self-healing, and a curve indicating almost complete healing agrees well with the recovery in member stiffness measured from loading test.