再生混凝土材料声学特性参数分析

Analysis of acoustic characteristics parameters for recycled concrete

为在混凝土无损检测中采集到高信噪比的声发射信号,对再生混凝土材料的声学特性参数进行了试验研究。通过模拟加载确定了声发射检测环境的门槛值,采用断芯试验测试了再生混凝土材料的检测时间参数,包括峰值鉴别时间(PDT)、撞击鉴别时间(HDT)和撞击闭锁时间(HLT);同时确定了信号在再生混凝土材料中的传播波速,为再生混凝土材料声发射检测参数的设置提供了一定的试验依据。该声发射检测参数设置具有操作简单易行、实时动态、对原有建筑物损伤小等特点,在混凝土结构声发射检测中具有较好的适用性。

In order to collect acoustic emission signals with high signal-to-noise ratio in non-destructive test of recycled concrete, the acoustic properties parameters of recycled aggregate concrete were studied experimentally. The value of threshold in the acoustic emission testing environment was determined by load simulation tests. Through pencil-breaking tests, time parame-ters such as PDT, HDT, HLT were obtained, and the velocity of acoustic emission signals in recycled aggregate concrete also were measured, which could provide test basis for parameter setting of non-destructive test of recycled concrete by acoustic e-mission. The proposed test method is characterized as convenient, real-time and little destructive to buildings, possessing good applicability in acoustic emission test of recycled concrete.