A Strut and Tie Model for Steel Fiber Reinforced Concrete Deep Beams

Abstract

A modified Strut-and-Tie model (MSTM) was developed for fibrous deep beams to include the contribution of steel fibers in the internal resistance for compression and tension. The proposed (MSTM) calculates the ultimate loads for several experimental results. The ratio between experimental results and MSTM predictions ( P u (EXP) /P u( MSTM) ) for 79 specimens is 1.20%. The results of the Strut-and-Tie for the American Code (P u (ACI) ) and Egyptian Code (P u (ECCS) ) are more conservative. The inclusion of steel fibers increases the shear capacity of deep beams by 13% and 19% respectively in compassion with ACI Code and the Egyptian Code. The ratio for ( P u (EXP) /P u (ACI) ) and ( P u EXP /P u (ECCS) ) are 1.36 and 1.43, respectively. The predictions of (MSTM) are consistent, accurate, and have a great degree of validation for (HSSFRC) deep beams with different geometrical properties, concrete compressive strength