The main components of cement are C3S, C2S, C3A, and C4AF. The adsorption activity sequence of these mineralized components is generally believed to be C3A>C4AF>C3S>C2S, among which C3A has the highest adsorption capacity for water reducing agents. Therefore, when the dosage of water reducing agents is constant, the fluidity of concrete decreases with the increase of C3A content. The loss rate of slump over time also increases. This is mainly due to the fact that most of the water reducing agents added will be adsorbed by C3A, while the main mineralized component C3S does not have enough water reducing agents to adsorb and disperse, resulting in a decrease in the fluidity of cement slurry. Multiple experiments have shown that if the C3A content in cement exceeds 8%, it will have an adverse effect on the fluidity of concrete.
Experiments have shown that supplementing SO3 in cement slurry with a high sulfate content water reducing agent has a certain effect. The addition of a certain amount of hydroxycarboxylate retarder can also inhibit the adsorption hydration of C3A, while the use of polyols and other retarders has no significant effect. Low priced water reducing agents can also be used and the dosage can be appropriately increased to meet the adsorption of C3A and have more remaining water reducing agents to improve the fluidity of mineralized components such as C3S. Due to the low price of such water reducing agents, they will not increase the cost of use.