Loading Capacity Prediction of Rubberized Reinforced Concrete Continuous Deep Beams

Abstract

Abstract Results of fourteen two-span continuous concrete deep beams were presented and discussed in this research. One sample was designed as a reference to be an ordinary reinforced concrete beam (ORC) while thirteen samples were made of rubberized concrete (RRC). The investigated parameters were the shear span/overall depth ratio (a/h) and the rubber replacement ratio with the fine and coarse aggregate. The volumetric replacement ratios were 0, 5%, 10%, 15%, and 20% of the fine aggregate while the coarse aggregate content was kept constant. The same replacement ratios were used for the coarse aggregate. Two shear span/overall depth ratios were used of 1.66 and 1.33. All beams showed the main crack formatted diagonally between the intermediate support and the applied load, indicating a shear failure. The excluded results were compared with those calculated by the strut and tie methods (STM) of the American and Euro codes. It was found that the predicted results of the American and European standards were conservative with mean values of experimental/calculated results of 1.29 and 1.24, respectively. Additionally, the effectiveness factors of the STM suggested by different researchers have been examined. It was found that those approaches were incapable to reflect the effects of the size and amount of rubber used in this study. Therefore, another effective factor was recommended to meet the requirements investigated in the current study. A respectable convergence between the predicted and the experimental results was found in which the mean and coefficient of variation values were 1.004 and 1.158%, respectively.