Application Of Grouting And Nondestructive Testing Technology For PC Beam

In recent years,with the rapid development of national traffic construction,prestressed concrete PC bridge has become the most important bridge in the construction of bridge.Although a growing number of bridges,the design of the form and structure of span continuous innovation,but in the operation of continuing problems with fracture,steel strand,prestressed box girder cracking failure completely,making the bridge damage and premature collapse,causing significant economic losses and social impact.It is an important cause of the accident that the non full grouting causes the external air and water into the pass to make the steel strand rust and break.In engineering construction,workers are not skilled in grouting operation,improper in grouting material and process,and are not well controlled in cement slurry consistency and expansion rate.After grouting,failure to anchor in time may cause slurry not fully filled with pores.In the inspection of project completion,there is not a unified standard of quality inspection in China,and the problem of filling not full is easily ignored.At present,people study more about the later detection method of grouting quality.There are few studies on the material,test,grouting process and flow process of grouting body.This paper not only studies the methods of quality detection in the later stage of grouting,but also studies and analyzes the whole process of grouting construction,providing reference for early stage construction,mid-term inspection and later maintenance and reinforcement of bridges.In this paper,the theoretical and Experimental Research on the grouting operation of PC beam and the test of grouting plumpness are made.The main contents are as follows:First of all,according to the existing domestic and foreign PC beam grouting problems,access to relevant information and literature,makes a brief overview of the current situation of the grouting material,technology and nondestructive testing,the research status at home and abroad combined with the impact echo method,analysis the related achievements and shortcomings.Secondly,the grouting technology is briefly analyzed with the grouting material,the related test and the three grouting techniques.The finite element software Fluent is used to simulate the flow of the slurry during the operation of the tunnel grouting,and the most likely location of the defects in the channel is analyzed.The basic theory and characteristics of stress wave are studied in detail by mathematical method.The impact echo method is mainly introduced from the basic principles and data analysis methods of stress wave detection.7 different conditions of the grouting model using the finite element software ABAQUS numerical simulation modeling of stress wave in the three-dimensional entity under the analysis of the propagation characteristics of internal surface and stress wave in different situations,to verify the reliability impact wave detection,to provide theoretical support for PC beam grouting construction and post detection.Finally,according to the engineering practice,three kinds of grouting defects are simulated.By comparing the results of qualitative and location tests with the design,combined with the actual engineering test results,we can verify the feasibility of the impact echo testing grouting fullness.The research results in this paper can help people find out the hidden danger of PC beam grouting safely and quickly,and ensure the safety of bridge construction and later operation.It has great economic and social significance.