Statistical study of cement additives with and without chloride on performance modification of Portland cement

The effectiveness of cement additives with and without chloride on the fluidity and the strength development of Portland cement was compared by using statistical full factorial design. The experimental results show that the cement additive containing CaCl2 and Ca(NO3)2 can enhance early strength of cement significantly. However, Ca(NO3)2 is less effective than CaCl2 even if it is combined with other organic chemicals such as alkanolamine and saccharide. No significant difference is found between CaCl2 and Ca(NO3)2 influencing the fluidity and 28 d strength of cement. The fluidity is determined by saccharide and its interaction with triisopropanolamine. The 28 d strength enhancement is determined by triisopropanolamine. The fluidity as well as the mechanical performance of treated cement can be significantly improved by combining Ca(NO3)2 with TIPA and saccharide.