Study into the freeze-thaw/ frost-salt resistance of high-strength B60–B100 concrete

Abstract

Introduction. The development of the Arctic Region and oil and gas fields in the North Atlantic Ocean leads to an increase in the production of high-strength concrete structures. Thus, it is becoming increasingly vital to make such low-permeability concretes more freeze-thaw resistant.Aim. To conduct experimental studies for obtaining reliable data required to develop a standardized approach to the normalization of freeze-thaw / frost-salt resistance parameters characterizing high-strength concretes.Materials and methods. The study was performed using concretes of eight compositions (B60–B100 compressive strength grades). The freeze-thaw/frost-salt resistance of high-strength concretes was determined using the third rapid method involving the saturation, freezing, and thawing of samples in a 5 % sodium chloride solution, as well as assessment of freeze-thaw resistance in terms of strength, mass variation, and the dynamic modulus of elasticity. A variety of methods for increasing the water saturation of highstrength concrete were examined in order to expedite the testing process of high-strength concrete for freeze-thaw resistance.Results. The studies into the freeze-thaw/frost-salt resistance of high-strength B60-B100 concretes revealed their high freeze-thaw resistance. Following 37 freeze-thaw cycles, the lower confidence limit for the strength of test samples was higher than that of control samples multiplied by a coefficient of 0.9. The frost-resistance grade of these concretes is above F2 300. No critical decrease in the dynamic modulus of elasticity is observed, which indicates a significant freeze-thaw/frost-salt resistance of all tested highstrength concrete compositions.Conclusions. The freeze-thaw resistance studies of high-strength concretes carried out at NIIZHB named after A.A. Gvozdev yielded experimental data required to subsequently develop a standardized approach to the normalization of freeze-thaw/frost-salt resistance parameters characterizing high-strength concretes.