The effect of a proprietary inorganic coating on compressive strength and carbonation depth of simulated fire-damaged concrete

Abstract

This paper describes the effect of an inorganic coating of concrete (ICC) on the residual compressive strength and carbonation depth of fire-damaged concrete. The concrete specimens were cooled by water-spraying, which is usually used for fire extinguishing in a real fire. The ICC was applied to enhance the residual compressive strength and to reduce the carbonation depth of fire-damaged concrete at different recuring periods. The results showed that the performance of concrete with ICC was better than that of uncoated concrete. After being exposed to 150, 300, 450, 600 and 750°C, compared to uncoated concrete, the compressive strength of concrete with ICC was enhanced by 3·8%, 3·7%, 11·0%, 17·3% and 6·1%, respectively. For concrete exposed to temperatures below 750°C, the carbonation depth of concrete with ICC was reduced significantly compared to the uncoated concrete. In the case of 750°C, the concrete was neutralised completely for both uncoated and coated concrete. The most obvious enhancement of the compressive strength and the most significant reduction of carbonation depth of concrete with ICC can be found after the concrete was exposed to 600°C. Similar results were confirmed with the other two types of concrete with different compressive strength.