Green concrete under normal and heat curing with fly ash from China and India

India and China currently lead the world in economic growth, infrastructure development, cement production, coal combustion in thermal power production as well as the generation of the fly ash as a by-product. While cement production generates 7% of the world’s carbon generation, disposal of fly ash continues to be a problem around the world including China and India. Green concrete with 80% cement replaced by fly ash has been recently developed to achieve target characteristic compressive strength of 45 MPa under normal curing with fly ash from China and 30 MPa under heat curing with a fly ash from India. Such concrete mixes are not only cheaper in cost but also have substantially lower energy and carbon footprint. In addition, they have substantial advantages in terms of long term durability and strength gain over normal concrete without fly ash. In order to adopt such materials in routine concrete works in countries like India and China, research is required to develop a simple mix design procedure that takes into account the variability of the fly ash and its unique characteristics such as particle size distribution, calcium content and amorphous phase that have important impact on reactivity and strength development. This paper reports an overview of recent research developments on green concrete made with high-volume fly ash and the recent experimental work undertaken using particular fly ash from China and India. Mechanical properties at 7-day and 28-day ages were recorded, and the material cost and environmental impact of different mixes were quantitatively evaluated. The green concrete shows encouraging prospects for the sustainable development with positive environmental implications.