Resistance to sulfate attack of magnesium phosphate cement-coated concrete.

Highlights • MPC coating can effectively prevent the invasion of the sulfate solution and protect the concrete. • MPC coating has a stable performance in the sulfate environment. Abstract The resistance to sulfate attacks of uncoated, magnesium phosphate cement (MPC)-coated, and epoxy-coated concretes has been studied by comparing changes in their compressive strengths, appearances, and ultrasonic velocities. XRD and scanning electron microscopy microanalysis have been conducted for the MPC-coated concrete before and after etching, and the intrinsic mechanism of the effect of MPC coating on the resistance of concrete to sulfate has been investigated. Results show that the structure and composition of MPC coating change in a sulfate erosion environment. And the coating is more closely bonded to the concrete and the structure is more compact than in other environments. MPC coating can significantly improve the erosion resistance of the concrete to sulfate in a manner that is superior to epoxy coating. So MPC coating has a significant protective effect on concrete against sulfate corrosion. [ABSTRACT FROM AUTHOR]