Study Of Accurate Localization Based On Embedded AE Transducers In Concrete

With the continuous development of the construction techniques and the use of newmaterials, the giant engineering, ultra-high-rise, and other major projects have been widelyinto sight. Security problem has become a serious problem. Real-time, online, in-situmonitoring of major projects and detection the safety problems early has become the focusand difficult problems of today’s engineering sector. That makes it possible to gain more timeto take effective measures. Concrete is the most widely used building material in civilengineering. And cracks appear on concrete in the course of applications is a commonphenomenon. With the crack propagation to a certain width, water seepage and steel corrosionwill be caused. And the integrity and safety of the structural will be destructed. It has a seriousaffect on the safety of the structures. Timely capture cracks in concrete structures, it will beable to improve the safety monitoring system for early warning role. Acoustic emission (AE)technique is a dynamic non-destructive testing technology. It can long-term, continuous andin-situ monitoring the security of defects and make early warning. And it is a very effectivemethod for the analysis of structural damage and material internal cracking information. Theobtained information on the spatial and temporal distribution of material internal damagesource localization is the most valuable part by AE source positioning technology. Inengineering applications, accurate location the positioning of defects and its development inthe structure, assess the extent of the danger, and then take measures to remedy, is also themajor functions and ultimate purpose of non-destructive detection.In this paper, study of AE in the specimens of cement-based materials, especiallyconcrete specimens.1-3cement-based piezoelectric composites that have good compatibilitywith concrete material have been developed for health monitoring of concrete structures.Transducers made of this type of composites have been especially designed to meet therequirement of being embedded into concrete materials. In the property calibration, thetransducers show broadband frequency response which is the basic requirement of AEtransducers. The1-3AE transducers will be preparation which is suit for embedded inconcrete. Some of the main acoustic emission parameters’ set are been study. And the way toconfirm the parameters is given. The set value of AE parameter in different conditions is given. The wave speed has a significant effect on the AE location results. AE wave velocity ismeasured in different distances condition under mortar, concrete and reinforced concrete threecement-based materials. Cement-based materials’ wave velocity variation related to distanceis given. The transducers are embedded in concrete and lead break AE3D-location test isimplemented. Compared with external test results, the accurate degree improve of AE3Dlocation through the embedded AE transducers is studied. The result show that the transducersembedded in concrete is feasibility and effectiveness for AE location.The above study results show that use an embedded1-3AE transducer array canimplement accurate location monitoring of the development of cracks in concrete structure byonline, real-time, in situ. And reflect the development of concrete crack damage and makeforecast and evaluation timely.