Evaluation of frost resistance of calcium silicate masonry units with ultrasonic pulse and resonance methods

Аннотация

Freeze-thaw resistance is one of the basic parameters of durability of construction materials. Methods of its evaluation vary; most often it is evaluated on the basis of strength of samples before and after the test of frost resistance. To certain extent, standards also codify the use of dynamic non-destructive methods (ultrasonic and pulse method) capable of detecting changes in micro-structure. The decisive factor for evaluation of frost resistance of calcium silicate bricks is compressive strength. Results of the research focused on verification of applicability of ultrasonic pulse method and resonance method proved practical applicability for evaluation of frost resistance of calcium silicate bricks. Difference between parameters of non-destructive testing before and after freezing was -1.1 % to -9.9 %, depending on the number of testing cycles and quality of calcium silicate bricks. Both ultrasonic pulse method and resonance method are applicable for evaluation of frost resistance of calcium silicate bricks. Relevant criteria were determined for evaluation of frost resistance of calcium silicate bricks based on the parameter of non-destructive tests.