Evaluation Method for the Bearing Capacity of Reinforced Concrete Beams Based on the Kaiser Effect

Abstract

The Kaiser effect is an important phenomenon that occurs in acoustic emission. The estimation of reinforced concrete structures based on acoustic emission is receiving widespread attention. Cumulative acoustic emission parameters were used for the preliminary estimation of Kaiser points through the step loading experiments on four simply supported reinforced concrete beams under bending load. Taking this Kaiser point as the centre, an appropriate interval value was determined. After functional fitting of the “load-acoustic emission parameter” curve, the difference between the estimated value and the measured value was calculated. The Kaiser point was modified in accordance with the “load-difference” curve. The modified Kaiser point was used to calculate the Felicity ratio. The ratio of the maximum load to the ultimate bearing capacity of the beams was calculated. The curves of the ratio and the Felicity ratio were obtained. Fitting of the corresponding relational function was performed. Based on the relational function, the ultimate bearing capacity of the beams was estimated according to the mean of the experiment. The results showed that if there was a significant difference between the preliminarily estimated value and the measured value of the Kaiser point, modifications can be conducted to avoid any significant difference in the Kaiser point caused by human factors. Using the Felicity ratio and based on function fitting, the maximum difference in the ultimate bearing capacity of the beams was estimated to be no more than 10%. Moreover, it was concluded that the estimated ultimate bearing capacity of the beams was characterized by high stability in the case of different sample data. This method will provide a theoretical basis for evaluating the ultimate bearing capacity of reinforced concrete beams under bending load based on the Kaiser effect.