Fracture Behavior of Concrete Exposed to the Freeze-Thaw Environment

Fracture behavior is an important parameter in evaluating mechanical properties, and it is related to crack risk and propagation in concrete. Freeze-thaw damage aggravates the degradation of mechanical properties and durability of concrete in a freeze-thaw environment, which is adverse to the safety of concrete structures. Although researchers have studied compressive, tensile, and bending strengths, the fracture behavior of concrete exposed to freeze-thaw cycles is frequently neglected. Additionally, fracture behavior is more sensitive to crack development caused by freeze-thaw damage. This paper was developed to investigate the influence of freeze-thaw damage on fracture behavior of concrete. Freeze-thaw cycles, compressive strength, and fracture energy tests were carried out. The results show that the toughness and fracture behavior both decrease with increases in freeze-thaw cycles, and this decrease becomes more obvious for concrete after a large number of freeze-thaw cycles, which should be considered seriously in the design of concrete in freeze-thaw environments. Air-entrained and mineral admixture concretes have better fracture behavior than fresh concrete after suffering the same freeze-thaw cycles. In particular, there exists good linear correlation between the fracture behavior and imposed freeze-thaw damage for various concretes.