Investigation on the Compatibility of Cement Paste with SNF and PCE based Superplasticizers

Background/Objectives: Cement particles disperse due to the flow character of the cement paste which also controls the quality of concrete. Cement particles also disperse due to the addition and action of Super-plasticizers (SPs) and this influences the high fluid paste behaviour. In the development of High Performance Concrete the Super-plasticizers and mineral admixtures such as fly ash plays an important role. SPs are normally adsorbed on the cement particles and sometimes the adsorption will not be even and slightly erratic. This is due to the clinker composition of cement and the type of SP used. Various combinations of materials including mineral admixtures affect the behaviour of the cement–based system and become incompatible like slump loss, delayed setting of concrete etc. Methods: In this study an attempt is made to explore maximum benefits of the compatibility between cement, Fly-ash and super-plasticizers (SP). The Flow table and marsh cone tests were conducted to determine the optimum dosage of the mixture. The different combination was tried in the cement mortar and the improvements in compressive strength were studied. Findings: Results show that the cement with 20% Fly-ash has the better compatibility with Poly carboxylate ether with optimum dosage of 0.9% by weight of cement. Improvement: The investigation shows that the polycarboxylate type superplasticizer has better compatibility with the different types of cement considered in this study.