The Test Of Corrosion Of Hydraulic Reinforced Concrete By Elastic Wave Non-destructive Testing

Duringthe service of reinforced concrete structures,the aging of materials and thedamage of structural such as concrete carbonization,concrete cracking and steel corrosion will occur due to the influence of external environment.The accumulation of these damages will reduce the durability and the bearing capacity of the building structure.If these problems are not found,and the scientific and effective measures are not taken in time to protect them,the building will be unable to meet the original design requirements and withdraw from the working state in advance.Corrosion of steel bars is one of the main factors leading to the durability of reinforced concrete structures.Therefore,how to detect,evaluate and control the corrosion state in time is an urgent problem to ensure the durability and safety of hydraulic structures.In this paper,the technical history and testing principle of elastic wave nondestructive testing method are described.The relationship between elastic wave characteristics and corrosion time is studied through laboratory tests,and the physical tests and numerical simulation methods are used to study the relationship between elastic wave characteristics and corrosion time.The relationship between elastic wave characteristics and the bearing capacity of corroded reinforced concrete is studied.The main research contents are summarized as follows:(1)Reinforced concrete specimens with different corrosion degrees were prepared by electrochemical method.The corrosion specimens were tested by elastic wave nondestructive method.The relationship between corrosion time and elastic wave parameters was analyzed.The experimental results show that with the increase of corrosion time,the variation of relative parameters of elastic wave is regular,and the corrosion degree of steel bar can be measured by elastic wave method.(2)The bearing capacity of corroded reinforced concrete specimens is tested and the influence of corrosion degree on the bearing capacity of reinforced concrete is analyzed.The residual bearing capacity of corroded reinforced concrete specimens is analyzed by numerical method.The results show that the numerical model is feasible to predict the corrosion bearing capacity of concrete.(3)Taking the verified numerical model as a bridge and combining the parameters of elastic wave with the residual bearing capacity obtained by simulation,a new method for predicting the residual bearing capacity of corroded reinforced concrete by using elastic wave method is proposed.It provides a new idea and basis for the practical application of elastic wave detection method.