Bond Strength and Influencing Factors of Magnesium Phosphate Cement Mortar and Concrete in Severe Cold Environment.

The rapid repair of concrete pavement under severe cold environment requires the repair materials to have high early strength and high bond strength with concrete. Using magnesium phosphate cement (MPC) with high early strength to prepare rapid repair materials is beneficial for achieving rapid repair of concrete pavement under non curing conditions in the winter. The effects of magnesium phosphorus ratio (M/P), boron magnesium ratio (B/M), and water cement ratio (W/C) on bond strength between MPC mortar and ordinary Portland cement concrete (OPC) in severe cold environment were studied, and the interface bonding mechanism were analyzed. The results show that M/P 4 ~ 5, B/M 0.02 ~ 0.03, and W/C 0.12 ~ 0.14 are more conducive to improve bond strength between MPC mortar and OPC in severe cold environment. The 3 h bond strength between MPC mortar and OPC can exceed 2.5 MPa, meeting the requirements for rapid repair of concrete pavement in severe cold environment. [ABSTRACT FROM AUTHOR]