Sustainability assessment of cements and concretes in the Indian context: Influence of supplementary cementitious materials

Considering that India is the second largest producer and consumer of cement in the world, it is understood that its production and use has a tremendous impact on the energy consumption and carbon dioxide emissions. More than 75% of cement in India is made by blending ground clinker with fly Ash, ground granulated blast furnace slag, limestone or other supplementary cementitious materials (SCMs). Further, there have been only limited studies on the sustainability assessment of cement and concrete that can give a clear picture of the impact and help mitigate it in future. The work presented here is based on realistic process maps made in cement plants and data collected from them. The concretes assessed are based on two typical strength grades obtained with blended cements, as well as only portland cement. The results highlight the importance of the SCMs in terms of total energy consumption and carbon dioxide emissions. The study also draws attention to the need to use high grades of concrete to better harness the benefits of the SCMs. Further, the need to generate more relevant data sets for the Indian context is recognized.