Research On Acoustic Emission Characteristics Of Concrete Based On Embedded Piezoelectric Sensor

With the wide application of concrete and new intelligent materials,huge projects and super high-rise buildings have received widespread attention.How to conduct real-time health monitoring on these major projects has become a hot research topic today.During service,concrete work with cracks is very common,which is often the cause of various structural damage.If the defects in the concrete structure can be monitored in real time,the advantages of structural health monitoring can be fully utilized.As a dynamic non-destructive testing technology,the acoustic emission technology can monitor the safety of the structure in real time,online,and is conducive to the analysis of the damage principle of the later structure.In today's engineering applications,it is the highest pursuit of non-destructive testing technology to locate the damage according to the monitored damage location to determine the health of the structure and then perform various remedial measures.Based on this,this paper uses self-made 1-3 cement-based piezoelectric sensors,preembeds them in concrete,and uses acoustic emission detection technology to monitor the early hydration and later uniaxial compression tests of concrete.The specific research contents are as follows:(1)According to the requirements of the concrete acoustic emission test for the sensor,a wide-band,stable 1-3 cement-based piezoelectric sensor was prepared.(2)The early-stage hydration acoustic emission characteristics of concrete with different water-cement ratios were studied by comparing 1-3 sensors with commercial sensors,and the superiority of the two sensors for acoustic emission monitoring of concrete hydration was analyzed.(3)Based on type 1-3 sensors,uniaxial compressive acoustic emission tests were performed on six groups of concrete cube test blocks with different amounts of graphene oxide,the acoustic emission characteristics and influence of mechanical characteristics.in concrete were obtained.The research results in this paper show that the embedded 1-3 type cement-based piezoelectric sensors have higher sensitivity to concrete acoustic emission signals and can be applied to the early-stage concrete hydration monitoring and later-stage uniaxial compression monitoring.The 1-3 type sensors have better acoustic impedance matching and higher sensitivity to concrete,they can respond to the mechanical properties and acoustic emission characteristics of the concrete throughout its life,online,in situ,and in situ.Reflect the development of concrete crack damage in time and make predictions and assessments,which enriches the theory of concrete health monitoring.