Interactions between coral sand and polycarboxylate superplasticizer and their effects on rheological properties of cement-based materials —— A review

Coral sand owns high porosity and water absorption, which has a strong adsorption effect on polycarboxylate superplasticizer (PCEs) in cement-based materials and will significantly decrease the dispersion ability of PCEs. This paper gives an overall review about the properties of coral sand and its effects on the fluidity and rheological properties of cement-based materials. The interactions between coral sand and PCEs, and the methods to reduce the adsorption of coral sand to PCEs are analyzed and discussed. The adsorption of PCEs by coral sand requires cations as the intermediate medium, as well as affected by the competitive adsorption of anions. Compound sacrificial agent may be a more promising scheme to improve the adaptability of PCEs in coral aggregate cement-based materials (CCMs) compare with the PCEs molecular modification. This paper can provide ideas for the development of high-performance CCMs and the research about the adaptation of PCEs.