Investigation of Interface Fracture between BFPMPC and Cement Concrete

Abstract

Recently, there has been wide concern about the mechanical properties of the repair interface for the magnesium phosphate cement mortar as a repair material with Portland cement concrete pavement. In this paper, based on the previous research results about basalt fiber reinforced and polymer modified magnesium phosphate cement (BFPMPC) mortar, the fracture behavior of the interfacial transition zone (ITZ) for BFPMPC and Portland cement concrete (PCC) was further pursued and studied. Firstly, a nanoindentation test was carried out on the repair interface with creep characteristics. Results showed that a synergistic effect and elastic moduli of multiple ITZs in repair interface were verified and determined. Then, the creep characteristic of ITZ was described by proposed fractional rheology characteristics in BFPMPC-PCC ITZ with further validation by finite element analysis. Finally, the interface fracture model combined with dislocation theory was proposed and analyzed. The results showed that satisfactory agreements had been obtained between the calculated results of interface fracture model and experiments. It was indicated that the fracture essence for BFPMPC-PCC ITZ was revealed by the interface fracture model. This finding, as a novel aspect and insight for interface fracture of bi-cementitious-based materials, was provided and the pursued direction of materials design for interface enhancement in pavement rapid repair was expected.