Xi’an University of Architecture and Technology
Traditional concrete crushing technology has the disadvantages such as large damage of coarse aggregates, serious mechanical wear and high energy consumption. These problems can be solved by microwave treatment of concrete before crushing. To evaluate industrial applicability of this technology, concrete specimens were heated by different microwave power, and compared with conventional heating method, the heating efficiency and macro-crack propagation mechanism of concrete were investigated. Then the uniaxial compressive strength test was carried out to obtain the strength weakening of concrete under different heat treatment conditions. The results illustrate that compared with the conventional heating method, microwave heating technology can effectively promote the internal and surface crack propagation of concrete, thus reducing the strength of concrete, and has higher efficiency and less energy consumption under high microwave input power. Besides, the results show that the concrete which is not completely dried is easy to burst at low temperature under microwave heating, and the relationship between burst time and power level is a negative power function, and the relationship between burst time and drying time is a positive power function.