Investigation of Strut Strength Using a Deep-Beam Database

摘要

Data from 360 deep beam tests was collected from available literature to perform a strut-and-tie model analysis on each of the beams using a simple deep beam strut-and-tie model. The capacities of bottle-shaped struts in the deep beam strut-and-tie models determined from experimental testing were compared with predicted strut strengths specified by ACI 318-08 and AASHTO LRFD Bridge Design Specifications (AASHTO 2007). For AASHTO LRFD, the comparisons showed that the strut stress provisions are unconservative for concrete strengths greater than 7000 psi (48 MPa). For ACI 318-08, the comparisons showed that the strut stress provisions are unconservative for concrete strengths less than 6000 psi (41 MPa) when used with the minimum amount of crack control reinforcement specified by ACI 318-08 and for concrete strengths greater than 6000 psi (41 MPa) for any amount of crack control reinforcement. Based on these findings, new strut strength provisions were developed for ACI 318-08 and AASHTO LRFD that provided increased conservatism.