The Influence of an Expansive Agent on the Performance of Cement-Stabilized Coral Sand

Using coral sand as an aggregate to build the base layer of pavement on islands and along coasts in China has the potential to not only reduce construction costs and time but also lessen carbon emissions during transportation. Due to coral sand’s fragility, porosity, and high water absorption, the amount of cement is higher than that of ordinary cement-stabilized gravel, which leads to the high strength but easy cracking of the base layer. The expansion agent is added to improve the shrinkage characteristics of cement-stabilized coral sand. To ensure the validity of our results, the mixing ratio of cement-stabilized coral sand was optimized according to its characteristics, and the effects of the cement content, the expansion agent type, and dosage on coral sand’s mechanical properties, dry shrinkage, and antiscour performance of cement-stabilized coral sand were studied using an orthogonal test. The results indicate that cement content is one of the most important factors affecting compressive strength, scouring, and dry shrinkage. The optimal mix ratio of cement-stabilized coral sand is 6% cement to 8% CAS expansion agent (accounting for cement), which is sufficient to meet the design criteria for heavy-duty traffic subbases.