Analysis of freeze-thaw damage and pore structure deterioration of mortar by low-field NMR

•Relationship between freeze-thaw damage and pore structure deterioration is studied.•Low-field nuclear magnetic resonance and mercury intrusion porosimetry are used.•Mass loss rate and relative dynamic elastic modulus are used to evaluate damage.•Pore structure deterioration equations can predict residual life of mortar exposed freeze-thaw. This study analyzes the deterioration process of mortar with three different water-cement ratios and compares the performances of mortar with and without air voids. The mass loss and relative dynamic elastic modulus of the specimens are the criteria for the macroscopic evaluation of freeze-thaw damage. Experimental methods combined rapid freeze-thaw testing, ultrasonic sound velocity, and low-field nuclear magnetic resonance (LF-NMR). The complete deterioration of mortar specimens is observed in detail to determine the relationship between freeze-thaw damage and pore structure deterioration. Results established a system to predict the residual life of mortar exposed rapid freeze-thaw cycles.