Study On Failure Characteristics Of Reinforced Concrete Flexural Members Based On The Historical Bending Stress

The concrete structure is easily deformed and then cracked at local locations due to the effects of self-weight,temperature stress and external continuous load.These micro-cracks and internal initial defects evolve and extend continuously under the influence of continuous loading,which morphology determine the final fracture path and failure characteristics of concrete.In order to explore the influence of historical bending stress on concrete flexural members,this paper studies the time-varying laws of reinforced concrete members under different continuous loading states from the macroscopic level,the bending damage process of concrete beams was studied based on the four-point loading failure test.Different levels of continuous loads were pre-applied to each group of reinforced concrete beams with the same mix ratio by using a bending-tension load-holding device in this study.The time-varying laws of concrete with different section positions and the mathematical prediction model of cumulative strain are determined though the statistics and analysis of the overall and local deformation data of concrete beams for a period of 40 days.The overall deformation degree prediction of the beam of the specimen is realized by the acoustic emission elastic wave velocity decay model.The obvious Kaiser effect of steel slag concrete was characterized in this paper based on the time domain law of characteristic parameters such as acoustic emission energy,amplitude and acoustic emission count.Excellent stress memory provides a research idea for identifying the historical stress state of concrete.The influence of load history on the deterioration of concrete flexural members is revealed by analyzing the deformation feature and peak load degradation.Furthermore,the flexural failure characteristics of concrete was analyzed and an overall damage process early identifying based on LSTM neural network was established in this study by combining the changed of the horizontal strain field,which provided an effective method for accurately evaluating the service state of concrete and predicting residual strength.