Investigation on the mechanical properties of CSA cement-based coating and its application

Due to the complexity and diversity of components, the performance of polymer-modified cement-based coating is restricted by many factors. In this study, silicone-modified polyacrylate (SPA) emulsion and calcium sulphoaluminate (CSA) cement are used as the main materials. Based on the pigment volume concentration (PVC) and the critical pigment volume concentration (CPVC), an appropriate value range of the polymer to cement ratio (p/c) is determined and the relationship between CPVC and p/c value is established. Besides, the effects of defoamer and film-forming additive on the coating are studied. The results show that the proper p/c value can significantly improve the performance of the coating. The polymer can form a continuous membrane structure, which can cover cement particles completely, so the comprehensive performance of the coating is optimized. And the optimal dosage of film-forming additive and defoamer is 3% and 0.14%, respectively. The application research shows that the performance of the prepared coating on the mortar surface is obviously better than the commercially available polymer-modified cement-based coating and organic coating.