Effect of Varying External Conditions on Internal Frost Damage in Concrete

Paper i proceeding, 2024

Concrete structures and infrastructures in cold regions can undergo internal frost damage. However, it is still not clear how external conditions, such as moisture boundary conditions and drying shrinkage influence the internal frost damage in concrete. To investigate this aspect, plain concrete cubes without air-entrainment were prepared for Freeze-Thaw Cycles (FTCs) in different ways. In addition to a reference group, four distinct groups exposed to FTCs were examined. Three groups experienced drying shrinkage and then FTCs under different conditions: a) in air, b) with water maintained on the top surface, and c) submerged in water. The fourth group was submerged in water both before and during FTCs. Ultrasonic and compression tests were conducted to assess internal frost damage. Results showed no internal frost damage in concrete cubes exposed to air during FTCs, while all specimens in contact with water exhibited internal frost damage of different magnitude. Furthermore, prior drying shrinkage intensified internal frost damage in concrete compared to conditions without previous shrinkage.