Research On Identification Of Grouting Sleeve Plumpness Based On Damping Vibration Method

In recent years,prefabricated building structures have been vigorously promoted and widely used in China.In the building structure,the beams,columns and walls are modularized,and the connection between each module plays a vital role.As one of the most commonly used connection methods,the grouting sleeve connection eliminates the need for welding of connecting reinforcement and completes the rapid connection.Whether the joint of the grouting sleeve is full determines whether the quality of the grouting sleeve meets the standard,and also directly affects the quality,safety and integrity of the fabricated structure.Therefore,the research on the detection method of grouting sleeve plumpness in the connection of prefabricated structures is more and more important,which is also of great significance to the safety and durability of prefabricated structures.As a nondestructive testing method,the damped vibration method is characterized by its high efficiency and low cost.This paper takes the plumpness of the grouting sleeve as the main research object,focusing on the influence of the plumpness of the grouting sleeve on the damping vibration parameters under different grouting material fluidity and sensor stress states,and establishes a set of fitting function models for the plumpness of the grouting sleeve based on the fluidity differentiation.The main research contents are as follows:(1)Taking the plumpness of the grouting sleeve as the research variable,it is proposed to analyze the damping vibration parameters of five grouting sleeve specimens with different plumpness,compare the regular relationship between the results of each parameter and the plumpness of the grouting sleeve,to verify the feasibility of the method of quantitative detection of the plumpness of the grouting sleeve by the damping vibration method and to optimize the characteristic parameters that can characterize different grouting plumpness.(2)Damping vibration is carried out on the grouting sleeve under different fluidity of grouting materials(initial time,1h,2h,3h,5h),various damping vibration parameters are collected and analyzed,damping vibration parameters and variation characteristics under different fluidity of grouting materials are obtained,and the relationship model between damping vibration parameters and plumpness under different fluidity of grouting materials is established,At the same time,the combination function model group is judged and optimized.(3)The one-to-one correspondence between grouting sleeve plumpness and stress value is established.Four groups of grouting sleeves with different sizes are damped to obtain the correlation between stress and damped vibration parameters.Through function fitting,the functional relationship and function model between different stress states and various damped vibration parameters are obtained,so as to establish a method for quantitative detection of grouting sleeve plumpness by damped vibration method.