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

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.

KEYWORDS:

• Magnesium phosphate cement
• repair material
• cement emulsified asphalt mortar
• rapid hardening
• pavement engineering

Acknowledgements

Thanks to all those who have provided guidance and assistance for this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was funded by the National Key Research and Development Program of China (No. 2021YFB2601000), National Natural Science Foundation of China (grant number 52178233). Shenzhen Science and Technology program (No. KQTD20180412181337494) and GDHVPS (2021, 2021QN02G957). This study was also funded by Shenzhen Science and Technology Program (GJHZ20210705141802009, JCYJ20220531101605012).