Concrete

Reducing Carbon Emissions with SCMs

Published

3 years ago

August 21, 2023

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Jens Mose and John Terembula, Product Line Management, FLSmidth A/S, introduce the type and availability of supplementary cementitious materials (SCMs) in this first part of a three-part article about the potential to increase the use of SCMs to reduce carbon emissions from cement manufacture. You will find parts two and three in the September and October issues of Indian Cement Review.

While much has been done to reduce emissions from cement production, the calcination of limestone is still a major contributor of harmful pollutants and must be addressed if cement manufacturers are to meet their sustainability targets. Fortunately, a number of supplementary cementitious materials (SCM) are available, which enable cement manufacturers to replace clinker and thus reduce CO2 emissions. However, adoption of these SCMs varies widely on a regional basis. In India and Brazil, for example, it is common to use fly ash and slag to reduce the clinker factor to as little as 65 per cent. In the US, however, the clinker factor remains high at around 95 per cent.
Worldwide, according to the Climate Technology Centre and Network, the ‘average clinker/cement ratio is about 0.81, with the balance comprising gypsum and additives such as blast furnace slag, fly ash, and natural pozzolana.’ The UNEP-sponsored white paper ‘Eco-efficient cements: Potential economically viable solutions for a low-CO2 cement-based materials industry’ suggests a reasonable worldwide average of 0.60 is achievable by 2050.
But how do we get to this figure? With many decades’ experience grinding a wide range of different materials in vertical roller mills, ball mills and hydraulic roller presses, FLSmidth is in a position to share our knowhow to help the industry make strides in reducing its carbon footprint.

Types of SCMs
SCMs include both naturally occurring materials and byproducts of other industrial processes. The Global Cement and Concrete Association (GCCA) groups SCMs according to how they harden : hydraulic SCMs harden in the presence of water (like Portland cement) and include granulated blast furnace slag (GBFS) and burnt shale oil. Pozzolanic materials require the additional presence of dissolved calcium hydroxide (Ca(OH)2) – a byproduct of the hydration of Portland cement – in order to harden. These include fly ash, silica fume, calcined clays, burnt rice husk and natural pozzolans. Hydraulic cements have a higher early age strength, while pozzolans continue to gain strength for a longer period, giving a higher long-term concrete strength. Both have been proven in construction applications. Limestone is not classified as either hydraulic or pozzolanic but also contributes to the hardening of concrete, putting it in an SCM category all of its own.

Table 1: Common types of SCMs

Find parts two and three of this article in the September and October issues of Indian Cement Review:
Part 2: Equipment selection for SCM grinding, Indian Cement Review, September 2023
Part 3: Expanding SCM use in the future, Indian Cement Review, October 2023

1 https://www.ctc-n.org/technologies/clinker-replacement
2 https://wedocs.unep.org/bitstream/handle/20.500.11822/25281/eco_efficient_cements.pdf
3 https://gccassociation.org/sustainability-innovation/health-safety-cement-innovation/clinker-substitutes/

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UltraTech Cement FY26 PAT Crosses Rs 80 bn

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19 hours ago

April 29, 2026

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UltraTech Cement reported record financial performance for Q4 and FY26, supported by strong volumes, higher profitability and improved cost efficiency. Consolidated net sales for Q4 FY26 rose 12 per cent year-on-year to Rs 254.67 billion, while PBIDT increased 20 per cent to Rs 56.88 billion. PAT, excluding exceptional items, grew 21 per cent to Rs 30.11 billion.

For FY26, consolidated net sales stood at Rs 873.84 billion, up 17 per cent from Rs 749.36 billion in FY25. PBIDT rose 32 per cent to Rs 175.98 billion, while PAT increased 36 per cent to Rs 83.05 billion, crossing the Rs 80 billion mark for the first time.

India grey cement volumes reached 42.41 million tonnes in Q4 FY26, up 9.3 per cent year-on-year, with capacity utilisation at 89 per cent. Full-year India grey cement volumes stood at 145 million tonnes. Energy costs declined 3 per cent, aided by a higher green power mix of 43 per cent in Q4.

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Concrete

Towards Mega Batching

Optimised batching can drive overall efficiencies in large projects.

Published

2 days ago

April 28, 2026

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India’s pace of infrastructure development is pushing the construction sector to work at a significantly higher scale than previously. Tight deadlines necessitate eliminating concreting delays, especially in large and mega projects, which, in turn, imply installing the right batching plant and ensuring batching is efficient. CW explores these steps as well as the gaps in India’s batching plant market.

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Large-scale infrastructure and building projects typically involve concrete consumption exceeding 30,000-50,000 cum per annum or demand continuous, high-volume pours within compressed timelines, according to Rahul R Wadhai, DGM – Quality, Tata Projects.

Considering the daily need for concrete, “large-scale concreting involves pouring more than 1,000–2,000 cum per day while mega projects involve more than 3,000 cum per day,” says Satish R Vachhani, Advanced Concrete & Construction Consultant…

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Concrete

Andhra Offers Discom Licences To Private Firms Outside Power Sector

Policy allows firms over 300 MW to seek distribution licences

Published

3 days ago

April 27, 2026

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The Andhra Pradesh government will allow private firms that require more than 300 megawatt (MW) of power to apply for distribution licences, making the state the first to extend such licences beyond the power sector. The policy targets information technology, pharmaceuticals, steel and data centres and aims to reduce reliance on state utilities as demand rises for artificial intelligence infrastructure.

Approved applicants will be able to procure electricity directly from generators through power purchase agreements, a change officials said will create more competitive tariffs and reduce supply risk. Licence holders will use the Andhra Pradesh Transmission Company (APTRANSCO) network on payment of charges and will not need a separate distribution network initially.

Licences will be granted under the Electricity Act, 2003 framework, with the Central and State electricity regulators retaining authority over terms and approvals. The recent Electricity (Amendment) Bill, 2025 sought to lower entry barriers, enable network sharing and encourage competition, while the state commission will set floor and ceiling tariffs where multiple discoms operate.

Industry players and original equipment manufacturers welcomed the policy, saying competitive supply is vital for large data centre investments. Major projects and partnerships such as those involving Adani and Google, Brookfield and Reliance, and Meta and Sify Technologies are expected to benefit as capacity expands in the state.

Analysts noted India’s data centre capacity is forecast to reach 10 gigawatts (GW) by 2030 and cited International Energy Agency estimates that global data centre electricity consumption could approach 945 terawatt hours by the same year. A one GW data centre needs an equivalent power allocation and one point five times the water, which authorities equated to 150 billion litres (150 bn litres).

Advisers warned that distribution licences will require close regulation and monitoring to prevent misuse and to ensure tariffs and supply obligations are met. Officials said the policy aims to balance investor requirements with regulatory oversight and could serve as a model for other states.