基于声发射技术的高强全珊瑚钢筋混凝土板破坏特性研究OA北大核心CSTPCD

To investigate the failure characteristics of coral aggregate reinforced concrete slabs,three high-strength coral aggregate reinforced concrete slabs with different reinforcement ratios(i.e.,0.85％,1.13％and 1.41％)were designed.Combined with acoustic emission technology,four-point flexural loading tests were conducted on the coral aggregate reinforced concrete slabs to reveal the influence of reinforcement ratio on the mechanical performance of high-strength coral aggregate reinforced concrete slabs.A quantitative dam-age assessment model was established based on the rate process theory of acoustic emission parameters,and a practical damage assessment criterion for the slab was further suggested.The results show that as the reinforce-ment ratio increases,the cracking load,cracking time,and peak load of high-strength coral aggregate rein-forced concrete slabs all increase,while the center deflection decreases by 11.29％.Two peak regions can be observed in the variations of acoustic emission parameters per unit time.It can serve as an assessment of crack initiation and a warning of failure for the slabs.According to the variations of cumulative values of acoustic emission parameters,the failure process of high-strength coral aggregate reinforced concrete slabs can be divid-ed into four steps:slightly-damaged degree(＜0.35),medium-damaged degree(0.35-0.66),highly-dam-aged degree(0.66-0.84)and heavy-damaged degree(＞0.84).The proposed model is suitable for damage assessment of high-strength coral aggregate reinforced concrete slabs with different reinforcement ratios.