Analysis of test methods for frost resistance of concrete

Abstract

Introduction. Frost resistance of concrete is one of the most challenging problems in concrete studies. Particularly important is the issue of methods of testing concrete for frost resistance. The existing standard methods require more detailed regulation of the test process in order to improve the reliability of the results.Aim. To analyze the regulatory procedures of testing concrete for frost resistance with a view to make suggestions for improving standards.Materials and methods. The analysis involved Russian and foreign standards and publications on methods of testing concrete for frost resistance.Results. The authors analyzed the methods of testing concrete for frost resistance, included in Russian and some foreign standards. The quality of determining the frost resistance of concrete can be improved by controlling the temperature while freezing and thawing, in particular, by assessing the temperature in the concrete of the test samples. Controlling the air temperature in the freezer should be recognized as insufficient. The criteria for the state of concrete samples during and after cyclic freezing and thawing should be further verified. It is necessary to continue full-scale testing of concrete under severe climatic conditions, taking into account the real conditions of freezing and thawing of concrete in structures, and comparing the results of laboratory and full-scale tests, including satellite samples.Conclusion. The analysis revealed the necessity to continue the research on clarifying the test methodology and criteria for assessing the state of concrete samples after freezing and thawing cycles. It is advisable to recreate devices for determining the dynamic modulus of elasticity of samples in freeze-thaw testing, to resume long-term full-scale tests of concrete under severe climatic conditions, and to develop a manual for creating frost-resistant concrete, taking into account the current level of concrete technology. Elimination of the existing drawbacks of the methodology will improve the reliability of test results.