Preparation and Performance of Cement-Stabilized Base External Curing Agent in a Desert Environment

Abstract

To explore and deal with the difficulty in curing cement-stabilized bases in desert environments, curing agents were prepared to enhance the curing effect on the base in this research. The composite curing agent was prepared through orthogonal experiments and the durability of the curing agent coating were studied by simulating a desert environment. Subsequently, the curing effect on the performance of bases was analyzed. Finally, the hydration degree of cement was studied via scanning electron microscope (SEM), thermogravimetric analysis (TG), and X-ray diffraction analysis (XRD), and the curing mechanism of the curing agent was explored. The results show that the composite (paraffin emulsion is the main component of the film, vinyl acetate-ethylene copolymer dosage is 20%, ethanol ester-12 dosage is 10%, and sodium silicate dosage is 18%) could effectively improve the water-retention performance (water-loss ratio: 2.36%) and mechanical properties of the specimen (7 d compressive strength: 7.48 MPa; 7 d indirect tensile strength: 0.70 MPa). The dry shrinkage coefficient of the specimen with composite curing agent was reduced by 116.26% at 28 days. The compressive strength of dry and wet freeze could reach 7.48 MPa and 6.88 MPa, respectively. The durability of the curing agent-coated base met the requirements of pavement performance in desert areas. The results of XRD, TG, and SEM indicated that the curing agent promoted hydration. In addition, the number of C-S-H gel and AFt crystals significantly increased. The curing difficulty of road bases in desert areas could be reduced effectively through the application presented in this study, which contributes to the conservation of natural and human resources.