전단철근으로 보강되지 않은 강섬유보강 초고강도콘크리트의 전단강도에 대한 실험적 연구

Abstract

In this study, fiber reinforced ultra high strength concrete beams were tested defining the shear behavior of fiber reinforced ultra high strength concrete and evaluating the previously suggested equations for shear strength of concrete members. The main variables of test are compressive strength of concrete(100, 200 MPa), volume fraction of steel fiber(0, 2%), shear-span to depth ratio(3.4, 2.0). According to the test results, specimens without fiber experienced the abrupt shear failure. In the case of fiber reinforced specimen with shear span ratio of 3.4, failure mode of test specimen is changed into flexural failure. And specimen with shear span ratio 2.0 experienced shear-compression failure mode. However, shear strength increase caused by the increase of compressive strength of concrete is not higher than effect of steel fiber inclusion. In order to make safe design of fiber reinforced ultra high strength concrete under shear, shear strength estimation equations are evaluated. Comparing estimated value with test results, shear strength contribution of matrix is over-estimated and shear strength contribution of steel fiber is under-estimated. Among all equations, equation of AFGC-Setra is most accurate.