Sarita Rai

Hydration of bagasse ash-blended portland cement

Hydration of bagasse ash (BA)-blended portland cement has been studied by employing a number of experimental techniques. It is found that in presence of BA setting times are increased and free lime is decreased. The compressive strength values increased with hydration time in the presence of BA and the values were found to be higher than that of control. The blended cement was found to be more resistant in an aggressive environment.

Effect of polyvinyl alcohol on the hydration of cement with rice husk ash

Effect of 3.0-wt.% polyvinyl alcohol (PVA) was studied on the hydration of ordinary Portland cement in the presence and absence of 10% rice husk ash (RHA) by employing different techniques. The results have shown that PVA increases the strength and decreases the porosity. The increase in strength is due to the interaction of PVA with cement, forming some new compounds that fill the pores or improve the bond between the cement. The two cements behave in a similar way, and hence, replacement of cement by 10-wt.% RHA is beneficial.

Effect of lignosulfonate, calcium chloride and their mixture on the hydration of RHA-blended portland cement

Abstract Hydration of 10 wt.% rice husk ash (RHA)-blended Portland cement has been studied in the presence of 2 wt.% CaCl 2 , 1 wt.% lignosulfonate (LS) and a mixture of the two admixtures by using different methods. Free lime determinations and differential thermal analysis have shown that CaCl 2 accelerates the pozzolanic reaction of Ca(OH) 2 and RHA. In the presence of mixture of two admixtures, lower amount of water is required for consistency of the paste. IR spectral studies have supported that the mixture of the two admixtures act as a strong accelerator for cement hydration. The compressive strength is highest in the presence of a mixture of the two admixtures at 28 days of hydration. The admixtures did not prevent the deterioration of the blended cement in corrosive atmosphere.

Hydration of composite cement

Abstract Hydration of OPC + GBFS + RHA composite cement has been studied by using consistency, setting time and compressive strength measurements. It is found that composite cement hydrated for 28 days has the highest strength.

Effect of Lomar-D on the Hydration of Portland Cement

The hydration of Portland cement in the presence and absence of a superplasticizer (Lomar-D) has been studied by using a number of experimental techniques. Compressive strengths are increased considerably in presence of 2.0 wt% Lomar-D at all the ages of hydration. Spectroscopic studies showed that Lomar-D is adsorbed at the surface of cement or hydration products. However, DTG/DTA studies have shown that Lomar-D interacts chemically with cement.

Hydraulic Behaviour of Ternary and Quaternary Blended Cements

Ternary and quaternary blends were made from Portland cement clinker, bag house dust, granulated blast furnace slag and gypsum. Hydration properties were studied by determining free lime, non-evaporable water contents, setting times, compressive strength etc. X-ray diffraction patterns of some of the hydrated samples were also recorded. The results have shown that in the presence of an appropriate amount of bag house dust and gypsum, the limitations of slag cements can be removed. The mechanism of hydration has been discussed.