초속경 시멘트 구조물의 화재 시에 내화도 특성에 관한 연구

Abstract

Concrete structures, known as fire-resistant materials, are exposed to high temperatures and are damaged by bursting, peeling, and destruction of the surface. Such concrete structures pose a risk of collapse. In general, in the event of a normal concrete fire, the strength decrease as the internal moisture evaporates and dehydrates, and only about 50% of the strength remains compared to the strength at room temperature at 550℃ and only about 15% of the strength remains above 800℃. In this study, ultra-rapid harding cement, which is a kind of special cement, has the advantage of having a higher initial strength than ordinary cement and shortening the working time. Accordingly, the industrial by-products of blast furnace slag and fly ash were substituted by 10, 20, and 30%, respectively, to measure the residual compressive strength and review the refractory properties. The change in the compressive strength residual rate after 1 day of curing of the specimen was almost incomplete, the highest at 22.2% at 800℃. at JA-FA20 after 7 days of curing, the highest level in JA-BA30 after 14 days of curing, and the final 28 days later, the compressive strength residual rate was 93% higher at 800℃. than JA-Plain in JA-BA30.