BEHAVIOUR OF REACTIVE POWDER RECTAINGULAR DEEP BEAM WITH SHEAR ZONE OPENING SUBJECTED TO REPEATED LOAD

Abstract

This investigation is devoted to study the experimental behavior of six simply supported Reactive Powder Concrete deep beams designed to be failed in shear loaded under two symmetrical point loads and subjected to monotonic and repeated load. Its blended with a same aspect ratio of steel fiber, but different value of the volume fraction which is either 1% or 2%. The tested deep beams had the same overall span of 1200 mm, constant cross section; 115 mm wide and 400 mm overall depth, and reinforced with the same amount of main tension bars (320), and a same amount of shear reinforcement ∅4mm@100 mm c/c. Each deep beam has two typical square opening. There are two different size of the opening; 40 mm and 80 mm. All deep beams have the same; water/cement ratio. Throughout the test operation, the crack patterns were drawn and identified the mode of failure of the tested deep beams. Also the load deflection curves were plotted It was found from observations of this study; a large opening often interrupt the load transfer by concrete struts in deep beams and cause a sharp decrease in strength and serviceability. Also, the presence of the opening in the deep beams decay the ultimate load of the RPC specimens with volume fraction 1% under repeated load by 2.27 times. In particular, it is shown that the presence of steel fiber, along with the RPC, play a crucial role in the transition from flexural to shear dominated failure modes of the beam.