Property evaluation of magnesia-based cement emulsified asphalt mortar (MCAM) as pavement repair material

Abstract

ABSTRACT In order to meet the requirements of compatibility and timeliness of repair materials for asphalt pavement, a rapid-hardening magnesia-based cement emulsified asphalt mortar (MCAM) is prepared. The results show that high temperature or high-temperature water bath treatment reduces the stability of MCAM, and MCAM prepared from emulsified asphalt with high softening point and low water content has better high-temperature stability. Increasing the asphalt-cement (A/C) ratio decreases the dynamic stability and stiffness modulus of the MCAM-repaired asphalt mixture, but increases its failure strain, which is determined by the material properties of the asphalt and cement phases. The splitting tensile strength of MCAM-asphalt mixture specimens are all above 0.8 MPa, and the strength ratio before and after freezing and thawing is above 90%, which is significantly higher than that of traditional asphalt-based, epoxy-based and polyurethane-based pavement repair materials. When MCAM is used to repair dried surface of asphalt mixtures, its pull-out bonded strength is significantly higher than that after wet and aged treatments. In addition, the microstructure of MCAM also shows that the asphalt phase and the cement phase are mixed together, and the microstructure becomes loose as the A/C ratio increases.