FLEXURAL BEHAVIOR OF HIGH STRENGTH RC SLABS WITH OPENING STRENGTHENING WITH WIRE MISH AND STEEL FIBERS

Abstract

This paper consists of experimental study on ability of use of wire mish strengthening and steel fiber to recover the flexural strength of the slab after configuring openings cut out with different shapes. 15 slabs (800*800*95 mm) made of high strength concrete were prepared and tested, these slabs were divided to gropes, the first group was with square openings, the second group with was rectangular openings. For each group, two different strengthening techniques were used wire mish (with different layers and widths) strips around openings and steel fibers (with four contents of 0, 0.5, 1.0 and 1% by volume fraction). The results showed that the two strengthening techniques increased the load-carrying capacities of the slabs with openings compared with the slabs without strengthening. The wire mish was more effective than the steel fibers technique. Wire mish and steel fiber reduced the cracks at the inside faces of opening and also wire mish prevent it at the inside corners.