Damage-Sensitive Mechanical and Transport Properties of Concrete Under Cryogenic Exposure

Abstract

This study investigates the residual performance of concrete after repeated cryogenic thermal shock and evaluates how water-to-binder (W/B) ratio, binder content, and fly ash replacement influence damage development. Seven concrete mixtures were tested at 28 days after up to three 1-hour liquid-nitrogen immersion cycles. Compressive strength, elastic modulus, reinforcing-bar bond strength and slip, length change, void content, and water permeability were examined to characterize load-bearing capacity, stiffness, interfacial behavior, deformation, and transport integrity. After three cycles, the control mixture retained 84% of its initial compressive strength but only 46% of its elastic modulus, demonstrating that stiffness was more sensitive to accumulated internal damage. First-cycle compressive-strength retention ranged from 65% to 99%, with mixtures having lower W/B ratio and higher binder content generally showing better retention. Bond strength decreased more modestly, whereas length-change records revealed rapid expansion during immersion and residual deformation after recovery. Void content increased after exposure, and measurable permeability generally increased, indicating development of connected transport paths; values unavailable after cracking were reported as N/A. The combined results show that elastic modulus, deformation, and transport properties complement compressive strength in assessing cryogenic damage and support performance-based selection of concrete mixtures for LNG-related structures.