Research on Standardized Method of Stress Release Method for Measuring the Stress of Concrete

Prestress detection is an important content of prestressed concrete structure detection, but there is no standardized method. The temperature shrinkage stress of super-long concrete structures after causes a large number of cracks which exceed the requirements of relevant specifications, but there is no effective method to detect the temperature shrinkage stress of concrete structures in situ. The finite element simulation of double groove stress release of concrete cover was carried out under four conditions of different sections and different stress states. Based on the analysis of the relations between strain release rate and groove depth, the 25 mm grooving method and the maximum release rate method of concrete cover were proposed. For concrete cover 25mm grooving method, the influence of temperature could be eliminated because of the grooving speed was fast. The data of maximum release rate method was stable and the predicted value was more accurate. The maneuverability and accuracy of the method were verified by field test of a certain project.