Experimental Research on Mechanical Properties of Concrete After Carbonization at High Temperatures

Through the high temperature test of the concrete after carbonization, the change rules of carbonization depth, mass loss, compressive strength and flexural strength were studied; the degradation mechanism of the mechanical properties of concrete after high-temperature carbonization was analyzed; the calculation formulas of compressive strength and flexural strength based on the mass loss ratios of concrete at high temperatures after carbonization were established. The results showed that with the continuons carbonization of concrete, the carbonization depth and mass loss increased; when the carbonization age was 7 d, 14 d, 28 d, the compressive strength of concrete decreased first, then increased and then decreased with the increase of temperature; the peak vale of the compressive strength of concrete with carbonization age of 14 d or 28 d appeared at 400 ℃; the general trend of the flexural strength of concrete decreased with the increasing temperature, but when the carbonization age was 14 d or 28 d and the temperature was 200 ℃, its flexural strength would increase slightly; the calculation fomulas of the compressive strength and flexural strength based on the mass loss ratios of concrete could be used to predict the compressive strength and flexural strength of concrete at different carbonization ages and different temperatures.