EXPERIMENTAL STUDY ON DEMOLISHING STEEL REINFORCED CONCRETE COMPONENTS BY INDUCTION HEATING

In the process of induction heating, the steel is heated directly by electromagnetic induction while the concrete is heated by heat conduction. The temperature and deformation differences between the steel and concrete are produced, which provide the possibility for the separation between the steel and the concrete. The induction heating separation tests of six steel reinforced concrete specimens without protective layers and eight steel reinforced concrete specimens with protective layers were carried out. The test results show that the trend of the temperature rise curve of the steel in different specimens is basically the same. When the temperature of the steel is below 450 ℃, the temperature rise of the steel is fast and the rate is approximately 30 ℃/min ~ 50 ℃/min. When the steel temperature is between 450 ℃ ~ 700 ℃, the steel temperature rise slows down and the rate becomes approximately 20 ℃/min ~ 30 ℃/min. When the steel temperature reaches 700 ℃, the steel temperature rises gently. When the steel temperature is no higher than 700 ℃, the temperature and expansion differences between the steel and the concrete increase linearly. The expansion difference between the section steel and concrete is mainly related to the height of the section steel web. When the height of section steel web is 300 mm and the expansion difference is not less than 1.80 mm, it is convenient to separate the section steel from the concrete. When the height of section steel web is 400 mm and the expansion difference is not less than 2.12 mm, it is also convenient to separate the section steel from the concrete.