Crack Resistance of Pre-Stressed Steel-Reinforced Concrete Composite Simple Supported Beams

Abstract

To study the normal section crack resistance of pre-stressed steel-reinforced concrete simply supported composite beams, the specific parameters such as the component steel content, the reinforcement ratio of non-pre-stressed and pre-stressed bars, and the section size of simply supported beams, are designed with different sections and reinforcement. Given the relatively poor bond property between steel and concrete, by introducing the bond property reduction coefficient, the formula for calculating the average crack spacing of pre-stressed steel-concrete simply supported composite beams is modified. Through the analysis of test data, the influence coefficient of concrete self-elongation between cracks on crack width is obtained, and the formula for calculating average crack width reflecting the characteristics of pre-stressed steel-concrete simply supported composite beams is obtained. The value of the expansion coefficient considering the uneven distribution of cracks is obtained by the crack distribution curve and the formula for calculating the crack width of pre-stressed steel concrete composite beams is given. The actual average crack spacing of the 5 pre-stressed steel-concrete simply supported beams in this test is 106.04 mm, which is calculated according to the above formula. The average value of the ratio between the calculated value and the measured value is 0.916, the standard deviation is 0.059, and the coefficient of variation is 0.064. The average value of calculated and measured crack widths of the beams is 0.927, the standard deviation is 0.194, and the coefficient of variation is 0.209.