STEEL FIBRE REINFORCED CONCRETE OPENING CORNERS

摘要

This paper presents some of the results of a comprehensive experimental programme underway at the Department of Civil Engineering, University of Roorkee, to evaluate the structural behaviour of opening corners reinforced with some of the prevalent and widely used detailing systems. Four different detailing systems were investigated for strength measured in terms of joint efficiency, ductility, crack control and ease of reinforcement layout and fabrication. None of the detailing systems investigated satisfied all the above four parameters, A substantial increase in post-cracking tensile strength, crack control, toughness and ductility can be achieved by adding steel fibers to the matrix. Subsequently, the four detailing systems were tested a fresh with 50 mm long crimped type Xorex steel fibres at a lower bound 0.75% volume fraction and subsequently one of the shortlised detailing system was investigated with 1.25%. 1.50%, 1.75% and 2% volume fraction of 25 mm and 50 mm long crimped type steel fibres. The investigations indicate that fibre volume fraction and aspect ratio have a significant effect on corner efficiency, ductility, toughness and crack control. There is an upper bound to the fibre volume fraction which can be effectively incorporated in the matrix without hindering mix workability and structural performance.