Study On Non-destructive Inspection Techniques Of Steel Bars In Reinforced Concrete

Recent years, with the durability problem of reinforced concrete structures becoming increasingly prominent, a large number of old buildings need to reinforce or repair. The steel bars, as an important factor of reinforced concrete structures, directly determine the capacity of the components, such as shear performance, bending properties, torsional resistance, and seismic behavior. Therefore, before the reinforcement, it is essential not only to test the number, diameter, location, protective leyer theichness and corrcaion degree of the steel bars,but alee to evaluata the resistance capacity and durability of steel bars or compotents.Given the above objective, the following work is done in this paper:1. The technical principles of the four current non-destructive locational testing of steel bars are presented. The advantages and disadvantages of these four types of detection techniques are evaluated. Experimental study on electromagnetic induction technique is made. The methods to improve testing accuracy are discussed..2. The technical principles of various electrochemical detection methods of reinforcement corrosion are introduced. Furthermore, these various electrochemical detection methods are evaluated. In addition, the experimental study on field detection of semi-cell potential method is carried out, and the error and precision of the detection are discussed. According to the approximate relation of the corrosion potential and corrosion current density, combined with Faraday's law, an approximate method to predict the life of components is deduced, which is beneficial for fast judgment on the durability of components.