Abstract:
In order to improve the microwave deicing efficiency of cement concrete without reducing its service life, the magnetite gravel was used as the microwave absorbing aggregate to prepare 6 kinds of concrete with different magnetite aggregate contents. And the effect of magnetite aggregate on microwave deicing efficiency and durability of concrete was studied. The results show that the magnetite aggregate improves the microwave deicing properties of concrete by increasing its dielectric loss and magnetic loss to microwave. With the increase of magnetite aggregate content, the complex dielectric constant, the complex magnetic permeability, the dielectric loss and the magnetic loss of concrete increase, the time required for the surface of concrete specimen to reach 0℃ decreases, and the temperature rise rate and the deicing effect increase. Magnetite aggregate enhances the abrasion resistance and compressive strength of concrete by improving its compactness, and enhances the frost resistance of concrete by improving its ability to resist crack development. With the increase of magnetite aggregate content, the abrasion mass and abrasion loss per unit area of concrete decrease. And after freeze-thaw cycles, with the increase of magnetite aggregate content, the mass loss rate and compressive strength loss rate of concrete decrease, and the relative dynamic elastic modulus increases. Magnetite aggregate concrete has both good microwave deicing properties and durability.