In the tropical climatic conditions that prevail in the Indian subcontinent, blended cements are reported to be an appropriate option for durable structures. The market acceptability of these cements is also on the increase.
The USP’s of the blended cements are primarily attributable to the decreased availability of the calcium hydroxide and the much compacted, less pervious hydrated cement paste matrix achieved on hydration. These aspects are however a function of the nature, fineness and pozzolanicity of the blending component viz.: flyash , GGBS etc used in the blended cement.
At the authors laboratory substantial work has been carried out to assess the efficacy of the different blending components to produce desirable hydration characteristics of the blended cement. The paper presents a comparison of the hydration characteristics of OPC and blended cements with different blending components through evaluation of the cement pastes at different ages of hydration.
The authors have made an attempt to relate the calcium hydroxide content, mineralogy and microstructure of the hydrated cement pastes at different ages of hydration to the efficacy of the different blending components to achieve properties amenable for a more durable concrete .