Author(s)

J.M. Louw, B.C. Koch & F.J. Koen

Abstract

Direct shear strength of concrete under impact J.M. Louw, B.C. Koch, F.J. Koen o/ ABSTRACT The strength of concrete when sheared off along an uncracked plane by an impact load was studied experimentally employing so-called push-off specimens. Thirty-eight plain samples had no reinforcement through the potential shear plane, while twenty-nine each had reinforcement penetrating the vertical shear plane horizontally. The primary variable was the concrete cube strength. The effect of preloading on the impact shear strength was also studied. Only a single rate of impact loading was applied. Twenty-three static tests were executed to serve as reference basis. In both groups of specimens the dynamic magnification factor in shear exceeded that in uniaxial tension or compression as recommended by the CEB-FIP Model Code (1990). A relatively small preloading and variation of the cube strength had little effect on this dynamic factor. INTRODUCTION Research^ on the

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