Rapid Repair of Road Surface with Magnesium Phosphate Cement: Case Study of Pavement Repair in Qingdao

To provide a new cold patch for asphalt pavement rehabilitation. In this study, emulsified asphalt (EA) was combined with Magnesium phosphate cement (MPC) to create an organic–inorganic composite repair material with rapid repair performance. The impact of material components on the performance of the MPC-EA was investigated, the ratio range to satisfy field construction performance requirements was optimized, and field tests were conducted on a section of Liaoyang East Road in Qingdao. The results showed that the borax retarder primarily functioned to regulate the setting time of the MPC-EA and enhanced its compressive strength under test conditions. Increasing borax from 6% to 12% increased the setting time of the MPC-EA by about 80% to 97% and had an increase of about 10% on the fluidity. However, increasing the content of EA considerably delayed the setting time of the MPC-EA, while reducing its fluidity and compressive strength. Increasing A/C from 0 to 0.2 increased the setting time of MPC-EA by about 80% to 135%, reduced the fluidity by about 14% to 25%, and reduced the compressive strength of the MPC-EA by about 60% to 65%. As ambient temperature significantly affects the setting time of the material, the ratio and performance should be adjusted based on climatic conditions, disease type, and restoration needs. This study introduces a novel organic–inorganic composite material with exceptional performance for the fast repair of asphalt pavement diseases. Additionally, it provides a valuable practical example of applying MPC materials in the realm of road rehabilitation.