Effect of waterproofing materials on resistivity and pore properties of concrete under insolation and rain

The poor resistance of concrete to insolation and rain remains a major contributor to waterproofing system failures. This study investigated the effect of waterproofing materials on the resistivity and pore properties of concrete when exposed to heating-cooling cycles. Three types of concrete and four different waterproofing conditions were prepared under heating-cooling cycles. Resistivity and pore properties such as air content and roundness were measured. The effects of heating-cooling cycles, waterproofing conditions, and concrete type were analyzed. The resistivity-air content model was established. The resistance of concrete to heating-cooling cycles (Crhc) was quantified. The results showed that heating-cooling cycles increased the air content and decreased the resistivity. The resistivity had a high correlation with the air content, and the coefficient of determination R2 exceeded 0.95. Specimens with the rigid-flexible composite waterproofing material (RFCW) had the highest Crhc. The penetrating crystallization of rigid waterproofing material and the high ductility of flexible waterproofing material worked together on concrete, making it the most effective in improving the resistance of concrete to heating-cooling cycles. This study contributes to the solution of waterproofing system failures and presents methods for calculating the resistivity of concrete and quantifying the resistance of concrete to heating-cooling cycles.