Modeling of Punching Failure Initiated by Concrete Splitting at Longitudinal Bar Level for Slabs without shear reinforcement
REN Da,LIU Jian and JIAO Chu Jie
DOI:10.11835/j.issn.1674-4764.2011.02.006
Received November 23, 2010,Revised , Accepted , Available online July 01, 2015
Volume ,2011,Pages 24-27
- Abstract
A new punching failure model has been developed for thinner slabs (≤120 mm thick) yet with a larger reinforcement ratio (＞085). On the assumption that the trigger of ultimate failure is the loss of dowel action caused by concrete splitting along the horizontal surface at longitudinal bar level, an equilibrium equation was established and an upper bound solution was obtained. The computation of punching shear capacity shows that for a total of 194 specimens collected, the mean and the coefficient of variation are 1072 and 0.250 respectively. As for the 116 members (out of all 194 ones) with the above character, it is found that there is little change of the mean (equal to 1017) yet an apparent decrease in the coefficient of variation (equal to 0184), which justifies the proposed hypothesis and refined mode in estimating punching resistance of such members.