Journal of Testing and Evaluation | 2019
Influence of Defects on Reinforced Concrete Fracture Performance in Improved Wedge Splitting Tests
Abstract
To predict the crack propagation and failure response of reinforced concrete structure, the effect of defects on reinforced concrete fracture characteristics was investigated. Based on the improved wedge splitting test device (an authorized patent No.\xa0ZL201410085111.7, China), specimens with various defects were tested. The formulas for the reinforced concrete double-K fracture parameters were derived, and a matrix describing the influence of defects was given. By this matrix, the defects were quantitatively transformed into the sectional loss and the double-K fracture parameters of these specimens were determined. The initial cracking load, unstable load, critical effective crack length, and unstable toughness were found to be improved significantly by the steel bars, but the initial toughness reduced slightly. In addition, with the increasing of sectional loss caused by defects, the initial cracking load, unstable load, and unstable toughness decreased in different proportions. Nevertheless, the defects were irrelevant to the critical effective crack length and the initial toughness. Besides, the critical interval of sectional loss ranged from 14.78 % to 15.48 % in the tests. Once the sectional loss was beyond this range, the steel bar enhancement on unstable toughness could no longer completely offset its attenuation caused by defects.