잔골재 종류에 따른 200MPa 초고강도 콘크리트의 역학적 특성 평가

Abstract

This paper presents an experimental study of the mechanical properties such as compressive strength, splitting-tensile strength, flexural strength, modulus of elasticity, and poisson's ratio of 200MPa ultra-high-strength concrete. Effects of primary variables such as fine aggregate type and curing age were studied in this research program. Silica sand, electric arc furnace oxidizing slag, and washed sand were used in the concrete as fine aggregate. For each fine aggregate type, mechanical properties were evaluated at age of 3, 7, 14, 28, 56, and 91 days. The mechanical properties of ultra-high-strength concrete specimens were characterized by extremely brittle and explosive behavior without notable micro-crack or advance warning before failure. Test results indicated that using silica sand as fine aggregate are effective in long term mechanical properties of ultra-high-strength concrete. A comparative study of existing prediction equations for mechanical properties of concrete was also conducted to asses their capabilities of predicting the mechanical properties of ultra-high-strength concrete. To this end, test results in the present study were compared with currents code equations.