Framework for Crack-Based Assessment of Existing Lightly Reinforced Concrete Deep Members

Throughout the life of existing concrete structures, there is often a need to assess the condition of members exhibiting shear cracks. This paper presents a framework for the crack-based assessment of lightly reinforced concrete deep beams that uses the observed crack geometry in conjunction with the two-parameter kinematic theory to provide member and crack-specific assessments of structural response. The results indicate that the method is able to capture the difference in shear response of nominally identical members that exhibit different crack geometries and is capable of predicting the stress distribution along the critical cracks. This novel approach is then used to examine large-scale deep beam experiments in the literature, and it is shown that the method can capture the response of members presenting different crack shapes with an average experimental-to-predicted ratio for the peak shear force of 1.04 and a coefficient of variation of 3.39%.