SHEAR BEHAVIOR OF RC DEEP BOX BEAMS STRENGTHENED INTERNALLY BY TRANSVERSE RIBS

Abstract

This research presents an experimental study of shear behavior of RC deep box beam strengthened internally by reinforced concrete transverse ribs. Eight beam specimens were tested, six box-deep beams and two solid-deep beams. The effect of type of concrete (NSC and SCC) and the number of internal cells on the behavior of deep box beam were tested. All beams were (2000mm) long and have been tested over a clear span of (1900mm) with a width of (450 and 200 mm) for top and bottom flanges respectively and (500mm) depth, the shear span-depth ratio (a/d) was (2) and longitudinal reinforcement ratio (ρ) was (0.00835). All beam specimens were simply supported under the effect of single point loading at mid span. The beam length, shear span-depth ratio (a/d), longitudinal and transverse reinforcement were kept constant for all tested beams. Test results indicated that all tested beams failed by shear and the failure took place by diagonal splitting mode for all tested beams except one beam, where its shear failure took place by diagonal compression mode.