Reinforcement Corrosion Monitoring Of Internal Concrete And Research On Bond Slip Performance Based On Piezoelectric Ceramic Transducers

On the traditional concept, people always think that reinforcement in structures are protected by the effect of the concrete under the concrete package, it is not easy to rust, but the corrosion of reinforcement in concrete is the universal existence phenomenon. With the problem of reinforcement corrosion in reinforced concrete structures have become increasingly prominent, we need a method to monitor the corrosion degree of steel bars, so it is able to timely find the reasons for the corrosion and avoid the formation of a major security risk and caused personal and property damage. So how to use accurate monitoring of structure during the corrosion condition of buried reinforced concrete interior is a very challenging task. In addition, in the reinforced concrete structure, the collaborative work of reinforcement and concrete depend on cohesive force between them. To this end, the bond-slip performance of reinforced concrete with corroded rebar for understanding the structure property and structure durability has very important practical significance.In recent years, piezoelectric ceramics is used as a kind of new intelligent materials, due to its easy to cut, fast response, the advantages of cheap, so it is widely used in civil engineering monitoring. Piezoelectric ceramic was applied to engineering structures internal has a very broad prospects about reinforced nondestructive monitoring. In this thesis, reinforced corrosion monitoring and corroded reinforced concrete bond-slip is studied in the experiment and numerical simulation based on piezoelectric ceramic. The main work is as follows:1. Test monitoring and numerical simulation of deformation of reinforced are conducted based on PZT wave propagation method, through both comparative analysis, it can obtain the amplitude of stress wave in the deformed bars with center frequency of excitation and propagation distance influences so that provide the basis for monitoring corrosion test inside concrete.2. The piezoelectric monitor was carried out on the electrochemical corrosion of reinforced concrete specimens, and compared the changes of signal amplitude under different corrosion rate, it is concluded that the signal received of sensor is gradually reduce with the corrosion rate rising under the condition of the rebar corrosion rate is low. But with the electrochemical corrosion and the corrosion of reinforced reach a certain extent, the received signal will begin to increase, the relationship between them is two times functions.3. The reinforced concrete which has monitored test was conducted the pullout test, we could get that ultimate bond strength of test pieces gradually reduced and it is two function relationship between the bond strength and the corrosion rate along with the increase of corrosion rate.4. Through simulate the reinforcement pullout tests of concrete specimens under different corrosion rate and verify the stress change under different corrosion rate of reinforced concrete, and to ensure that the bonding slip component degradation law is true.