Effect of non-intumescent fireproof coating on the durability of concrete exposed to elevated temperature

Abstract

The durability of concrete can be severely damaged by elevated temperatures. Fireproof coating is often used to improve the fire resistance of concrete. Fireproof coating can effectively reduce the impact of extreme temperatures on the durability of concrete. To investigate the effect of fireproof coating on the durability of concrete, concrete specimens coated with non-intumescent fireproof coating was heated to the target temperatures of 200 °C, 400 °C, 600 °C and 800 °C with an electric furnace. The effects of fireproof coating on the temperature in the concrete specimen, the mass loss, the water absorption and the carbonization resistance of concrete were studied. The thickness of the non-intumescent fireproof coating was 5 mm, 10 mm and 15 mm, respectively. The durability of concrete exposed to elevated temperatures was enhanced as the thickness of the fireproof coatings increases. When the furnace chamber was heated to 800 °C and maintained at this temperature for two hours, the temperature of specimen with 15 mm thick non-intumescent fireproof coating was reduced by 58.92% and 13.50%, respectively, compared with that of the specimen without fireproof coating. At temperature of 800 °C, the mass loss of coated specimens was reduced by 8.3% compared with that of uncoated specimens. The water absorption rate of concrete coated with 15 mm thick non-intumescent fireproof coating at temperatures of 200 °C, 400 °C, 600 °C and 800 °C decreased by 18.45%, 26.77%, 21.14% and 11.98%, respectively. The carbonization depth of concrete with non-intumescent fireproof coating is less than that of uncoated concrete.