India's production of ordinary Portland cement (OPC) continues to fall as the manufacture of blended cements, such as Portland pozzolana cement (PPC), Portland slag cement (PSC) and composite cements based on granulated blastfurnace slag and fly ash, increase on the back of strong demand.
Blended cements currently account for 73 per cent of total cement production in India, compared to 27 per cent for OPC, according to the recent GCCA India report, ‘Blended cement - green, durable & sustainable.’ So pioneering is India in the area of blended cements that other formulations, including Portland limestone cement (PLC) and limestone calcined clay cement, are also at varying stages of development in the country.
The lead driver in the use of blended cements is their ability to reduce CO2 emissions. India has been working hard to lower its greenhouse gas emissions through the use not only of blended cements but also increased usage of alternative fuels and reducing the clinker factor. Today, direct CO2 emissions for OPC are around 740kg of CO2/t cement. PPC can reduce this by 31 per cent to 507kg, composite cements by 53 per cent to 351kg, and PSC by 59 per cent to 312kg. By broadening the raw material base of its cement production, India is also helping to conserve its natural resources, particularly limestone.
The GCCA report also states that India's production potential is significantly expanded through the use of blended cements. If the domestic production base produces 100 per cent OPC, the capacity is 267Mta, whereas under a 100 per cent blended cement scenario, capacity would be extended to 350Mta of production capacity.
With the global blended cement industry valued at US$295.4bn in 2017 and expected to rise by over seven per cent in 2019-25, standards are evolving worldwide to accommodate the growing range of blended cement products. Since its introduction to the US in 2005, more than 6Mt of PLC has been used across the country with a total of 44 states now approving its use for transportation and concrete applications.
In Europe, the new standard EN-195-5-2021 for Portland composite cement CEM II/C-M, containing at least 50 per cent clinker, was introduced in May 2021. This allows for up to 50 per cent natural calcined pozzolana and covers calcined clays, laying the foundation for the market penetration of LC3 cements and other new formulations.
According to the GCCA India report, cements using limestone as a filler currently represent 25-30 per cent of global cement production, a share that is expected to increase by up to 48 per cent by 2050. Meanwhile, cements based on calcined clay and ground limestone are expected to reach 27 per cent of global cement production by 2050.
Such is the demand for low-carbon products, cement companies around the world are focusing their efforts on ambitious emissions targets and developing low-carbon cement and concrete products. Cemex, for example, is aiming for its Vertua low carbon products to account for more than half of its total cement and concrete sales by 2025. In the opening quarter of 2022, Vertua cement and concrete made up 34 and 31 per cent of total sales, respectively, almost double that seen in the prior year.