Concrete

Material Benefits

Published

4 years ago

June 13, 2022

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Supplementary cementitious materials are changing the way and the speed at which cement manufacturing is moving on the spectrum of environment sustainability. With large stakes on the line for achieving net zero targets, how is the Indian cement industry rising up to the challenge, finds out ICR.

Across the globe, cement is one of the most consumed and important materials for building all infrastructure. From homes, to factories, roadways or tunnels, everything would require cement in one form or the other. India especially is moving towards becoming infrastructurally strong with new projects in the works across the sub-continent. All infrastructural projects demand the consumption of concrete and cement, which has led to the rise of concrete requirement, thus, increasing the production of cement.

India’s cement production is expected to reach 381 million tonnes by 2021-22, while the consumption is likely to be
around 379 million tonnes in light of the country’s renewed focus on big infrastructure projects. Source: RBI Reports

India is the second largest producer of cement. Limestone is at the core of its production as it is the prime raw material used for production. The process of making cement involves extraction of this limestone from its quarries, crushing and processing it at the cement plant under extreme temperatures for calcination to form what is called a clinker (a mixture of raw materials like limestone, silica, iron ore, fly ash etc.). This clinker is then cooled down and is ground to a fine powder and mixed with gypsum or other additives to make the final product, cement.
Limestone is a sedimentary rock composed typically of calcium carbonate (calcite) or the double carbonate of calcium and magnesium (dolomite). It is commonly composed of tiny fossils, shell fragments and other fossilised debris. This sediment is usually available in grey, but it may also be white, yellow or brown. It is a soft rock and is easily scratched. It will effervesce readily in any common acid. This naturally occurring deposit, when used in large volumes for the cement making process is also depleting from the environment. Its extraction is the cause of dust pollution as well as some erosion in the nearby areas.
The process of calcination while manufacturing cement is the major contributor to carbon emission in the environment. This gives rise to the need of using alternative raw materials to the cement making process. The industry is advancing in its production swiftly to meet the needs of development happening across the nation.

Aligning Sustainability Goals
In one of its recent bulletins, owing to India’s announcement at the Glasgow Climate summit to reach net-zero by 2070, the RBI noted that with India aiming to reach half of its energy requirements from renewables and reduce the economy’s carbon intensity by 45 per cent by 2030, it ‘necessitates a policy relook across sectors, especially where carbon emission is high’ and ‘cement industry is one of them.’ However, it said, recent developments in green technologies, particularly related to reverse calcination, offer ‘exciting opportunities’ for the cement sector.
The RBI report noted that India’s cement production is expected to reach 381 million tonnes by 2021-22 while the consumption is likely to be around 379 million tonnes, in the light of the country’s renewed focus on big infrastructure projects like the National Infrastructure Pipeline, low-cost housing (Pradhan Mantri Awas Yojana), and the government’s push for the Smart Cities mission is likely to drive demand for the cement in future. On similar lines, according to the Eco-Business news portal report of April 2022, the India Energy Outlook 2021, which notes that most of the buildings that will exist in India in 2040 are yet to be built. Their projection suggests that urbanisation in the near future will demand an increase in infrastructure, which will ultimately lead to increase in the cement consumption.
With these forecasts in mind, RBI has recommended that there is a need to align India’s economic goal with its climate commitments by implementing emerging green tech solutions. It has also recommended an increase in finance towards green sustainable solutions through subsidised interest loans, proactive engagement with the leading research institutes and countries involved with green tech-related innovation in the cement industry.
“When clinker is blended with other supplementary cementitious materials like fly ash, slag or both, products are called Portland Pozzolana Cement (PPC), Portland Slag Cement (PSC) and composite cement (CC) respectively. Blended cement products have a much lower carbon footprint than OPC. Since clinker manufacturing is the phase where most thermal energy is consumed and CO2 is emitted, reducing clinker factor in cement not only results in lowering the process CO2 but also the thermal energy and electrical energy requirements,’’ says Manoj Kumar Rustagi, Chief Sustainability and Innovation Office (CSIO), JSW Cement.

Increased cement plant capacity, reduced fuel consumption
and lower greenhouse gas emissions are some of the
advantages of blended cement.

Alternative Raw Materials
Alternative cementitious materials are finely divided materials that replace or supplement the use of portland cement. Their use reduces the cost and/or improves one or more technical properties of concrete. These materials include fly ash, ground granulated blast furnace slag, condensed silica fume, limestone dust, cement kiln dust, and natural or manufactured pozzolans.
“Each material has its own composition and behaves differently during the burning process. In order to maintain the consistent clinker quality and stable clinkerisation process, we need to analyse these materials with respect to quality (during raw mix design) and also impact on the environment (if any harmful gases are released). There are certain materials which come in both ARM and cement additives like Ashes from coal fired thermal plants and slag from steel plants that have to be looked at from various angles,” says Gulshan Bajaj, Vice President (Technical), HeidelbergCement India.
The use of these cementitious materials in blended cements offers advantages such as increased cement plant capacity, reduced fuel consumption, lower greenhouse gas emissions, control of alkali-silica reactivity, or improved durability. These advantages vary with the type of alternative cementitious material.
Cement manufacturers are moving towards incorporating these supplementary cementitious materials in their raw material:
Fly Ash: Containing a substantial amount of silicone dioxide and calcium oxide, fly ash is a fine, light, glassy residue generated during ground or powdered coal combustion.
Ground Granulated Blast-furnace Slag (GGBS): It is a by-product of the iron and steel industry. In the blast furnace, slag floats to the top of the iron and is removed. GGBS is produced through quenching the molten slag in water and then grinding it into a fine powder. Chemically it is similar to, but less reactive than, Portland cement.
Silica Fume: It is a by-product from the manufacture of silicon. It is an extremely fine powder (as fine as smoke) and therefore it is used in concrete production in either a densified or slurry form.
Slag: It is a by-product of the production of iron and steel in blast furnaces. The benefits of the partial substitution of slag for cement are improved durability, reduction of life-cycle costs, lower maintenance costs, and greater concrete sustainability. The molten slag is cooled in water and then ground into a fine powder.
Limestone Fines: These can be added in a proportion of 6 to 10 per cent as a constituent to produce cement. The advantages of using these fines are reduced energy consumption and reduced CO2 emissions.
Gypsum: A useful binding material, commonly known as the Plaster of Paris (POP), it requires a temperature of about 150OC to convert itself into a binding material. Retarded plaster of Paris can be used on its own or mixed with up to three parts of clean, sharp sand. Hydrated lime can be added to increase its strength and water resistance.
Cement Kiln Dust: Kilns are the location where clinkerisation takes place. It leaves behind dust that contains raw feed, partially calcined feed and clinker dust, free lime, alkali sulphate salts, and other volatile compounds. After the alkalis are removed, the cement kiln dust can be blended with clinker to produce acceptable cement.
Pozzolanas: These materials are not necessarily cementitious. However, they can combine chemically with lime in the presence of water to form a strong cementing material. They can include – volcanic ash, power station fly ash, burnt clays, ash from burnt plant materials or siliceous earth materials.
Dr Sujit Ghosh, Executive Director – New Product and R&D, Dalmia Cement (Bharat), says, “Blended cements made using supplementary raw materials, have ‘additional’ activated silica (SiO2) and/or activated lime (CaO), which when co-processed with cement clinker, provide ‘additional’ cementitious gel paste (complex calcium-silica-oxide-hydrates) when mixed with water, that renders improved strength and durability to the cement-concrete structure.”
He adds, “With specialised processing and with the use of performance enhancers, blended cements using supplementary raw materials, provide acceptable rate of strength gains, comparable to pure-clinker cement and top-class long-term durability, with lower carbon footprints and at the same time effectively finding value-solution to other industry wastes!”
Besides having the advantage of lower emissions and better environmental conditions, use of supplementary cementitious materials also has a cost benefit. “Cost of production depends on the plant location, limestone and raw material quality. The source of alternative raw materials for some plants are significant and in some instances because of high logistic cost economics do not work out. For example, if a cement plant is located near the industry where chemical gypsum is generated, there will be a significant gain to that particular cement plant,” says Rajpal Singh Shekhawat Senior General Manager (Production and QC), JK Lakshmi Cement.

Bio Solutions
Researchers at the Indian Institute of Technology, Madras, are finding ways to use bacteria to develop bio-friendly cement and reduce carbon dioxide emission, as per a report in The Hindu earlier this year.

Use of other industrial waste will make way for a circular economy and reduce ocean pollution and landfills

Professor GK Suraishkumar and assistant professor Nirav Bhatt in the Department of Biotechnology and Subasree Sridhar, a research scholar, are conducting the research. They have developed a mathematical model to produce an alternative to current cementation process. They have suggested the use of bacteria like S Pasteurii, which will microbially-induced calcite precipitation.
This bio cement will require temperatures in the range of 30 to 40 degrees as opposed to the traditional process that would require over 900 degrees for the calcination process. The emitted carbon dioxide will be negligible in this case and industrial waste like lactose mother liquor and corn steep liquor can be used as the raw materials for the bacteria, thus making the manufacturing of this cement more economical.
One of the most important ways of reducing carbon emission in cement manufacturing is the use of alternative raw materials from various other industries. This gives way to a circular economy, utilising waste from other industries and bettering the environment with reduced emission of harmful gases, especially carbon dioxide. It also helps the avoidance of landfills or ocean pollution, as waste of industries is utilised in manufacturing cement. Overall, new compositions of cement are the future.

-Kanika Mathur

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Concrete

CarbonStrong Raises Rs 125 Million To Scale Low Carbon Cement Tech

To build capacity of 100,000 tonnes a year

Published

3 days ago

August 28, 2026

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CarbonStrong has raised Rs 125 million (125 mn) to scale a low carbon cement technology and build commercial production capacity. The startup was founded in 2022 by Harsh Jain and Vikramaditya Singh and has moved from customer trials to plans for industrial supply. The company said its material replaces up to 50 per cent of cement in concrete while reducing costs and improving durability.

CarbonStrong states the product is around 30 per cent cheaper than cement and compatible with existing concrete plants, reducing the need for new equipment and operational disruption. Trials and paid pilots have been conducted in Bengaluru, Hyderabad and Chennai with demonstration projects involving ready-mix firms and precast manufacturers. Compatibility with current workflows forms a central part of the commercial strategy, aiming to ease adoption by builders and contractors.

The funding will support construction of a facility with capacity of up to 100,000 tonnes (100,000 t) a year over the next two years to supply early customers commercially. The firm is also developing materials from steel slag, copper slag and mine tailings to expand its feedstock base, while noting the technical challenge of homogenising different waste streams. Recognition by HCL ClimaForce in 2026 and by the Avaana-Startup India-NITI Aayog AIM Grand Challenge in 2025 has underscored progress.

Industry adoption remains the principal test and will require consistent material performance, supply reliability and competitive economics. CarbonStrong projects the Indian market for cement substitutes could reach Rs 250 billion (250 bn) by 2030 and has set an ambition to produce 10 million tonnes a year by 2035 (10 mn t), a target far above its near term capacity. Moving from pilots to production demands capital, manufacturing discipline and customers willing to specify the material beyond demonstrations. The recent Rs 125 million raise is intended to fund the next phase of scale and to demonstrate that industrial waste can become a dependable input for lower carbon construction.

Concrete

Protect Your Margins

Published

3 days ago

August 28, 2026

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In a research-backed article, Dr SB Hegde examines why carbon-adjusted profitability and LC3 will decide the next set of winners in cement manufacturing.

The Indian cement industry has achieved world-class operational efficiency through lower specific energy consumption, high plant utilisation and a reduced average clinker factor of approximately 67.5 per cent. These traditional measures of operational excellence remain essential. However, they are no longer sufficient. Carbon now carries a measurable financial cost under India’s Carbon Credit Trading Scheme (CCTS) and under European carbon markets. Future leadership will be defined by carbon-adjusted profitability, the ability to generate strong returns while systematically lowering the carbon intensity of every ton sold.
Limestone calcined clay cement (LC3) offers a practical, scalable pathway to achieve this dual objective. By replacing up to 50 per cent of clinker with calcined clay and limestone, LC3 can reduce CO2 emissions by 30–40 per cent while delivering comparable or superior durability performance.
This article examines the technical foundations of LC3, European industrial practices, the emerging Indian carbon market and a concrete roadmap for Indian companies to embed carbon-adjusted metrics and LC3 into daily operations, incentives and commercial strategy.

Limits of traditional operational excellence
For many years, plant performance has been judged primarily by five indicators: specific heat consumption, specific power consumption, kiln and mill utilisation, clinker factor and overall equipment effectiveness. These metrics drove continuous improvement and helped the industry reduce energy use and increase the share of blended cement. Three structural changes have rendered them incomplete as sole measures of success.
First, carbon now carries a real or opportunity cost. Plants that improve volume or lower cash cost while raising or stagnating emissions intensity create a hidden liability that will surface as CCTS trading matures and as green procurement expands.
Second, lower-carbon products such as LC3 and high-performance blended cements are creating differentiated market segments. Customers in infrastructure, real estate and export-oriented construction are beginning to specify embodied-carbon limits.
Third, investors and lenders increasingly treat carbon intensity as a financial risk factor. Traditional KPIs can mask the divergence between short-term cash profit and long-term carbon-adjusted value.

What is carbon-adjusted profitability?
Carbon-adjusted profitability evaluates normal profit after explicit adjustment for carbon performance. A practical expression is:
Carbon-Adjusted EBITDA = Conventional EBITDA – Carbon Cost + Green Premium Income
Carbon cost may be an internal carbon price, the actual cost of purchasing Carbon Credit Certificates under CCTS, or the opportunity cost of high emissions relative to peers. Green premium income arises when customers pay more for verified lower-carbon cement or when the company sells surplus credits. Tracking both conventional and carbon-adjusted profit side-by-side gives management a clearer picture of value creation under evolving market rules.

Table 1. Traditional KPIs versus Carbon-Adjusted Leadership Metrics
Traditional Focus New Leadership Metric Why It Matters
Specific energy consumption Emissions intensity (kg CO2/t cement) Directly linked to future CCTS and CBAM costs
Kiln utilisation Carbon-adjusted contribution margin Reveals true value of incremental volume
Clinker factor Share of lower-carbon products sold (incl. LC3) Measures commercial success of the transition
Power cost per tonne Effective carbon cost per tonne sold Expose hidden liabilities
Absolute EBITDA Carbon-adjusted EBITDA + green premium Aligning profit with future market reality

LC3: Technical foundations and performance advantages
LC3 is a ternary blended cement that typically combines approximately 50 per cent clinker, 30 per cent calcined clay, 15 per cent limestone and 5 per cent gypsum (the classic LC3-50 formulation). The decisive technical advantage is that clay is calcined at 700–850 °C, far below the 1,450 °C required for clinker production. This lower temperature, together with the substantial reduction in clinker content, delivers CO2 reductions of 30–40 per cent relative to ordinary Portland cement (OPC).
Chemistry is synergistic. Calcined kaolinitic clay (metakaolin) reacts with calcium hydroxide from clinker hydration and with limestone to form additional C-A-S-H gel and carboaluminate phases. These phases densify the microstructure, reduce porosity and improve durability.
Field experience shows superior resistance to chloride ingress, sulphate attack and alkali–silica reaction. Early-age strength can match OPC with high-reactivity clays; later-age strengths routinely meet 42.5 and 52.5 grade requirements.
Importantly, LC3 does not require high-purity kaolin. Clays with 40 per cent or even lower kaolinite content can be activated successfully, expanding raw-material availability across India. Calcination can use adapted rotary kilns or dedicated flash calciners, making the technology compatible with existing plant infrastructure and far less capital-intensive than carbon capture.
Economic analyses show that LC3 can be produced at equal or lower cost than OPC in many locations because of reduced energy demand and cheaper clay. Life-cycle assessments consistently report 30–40 per cent lower embodied CO2 per tonne of cement.
Table 2. Comparative profile: OPC versus LC3-50
Parameter OPC LC3-50
Typical clinker content ~95 per cent ~50 per cent
CO2 emissions (relative) Baseline (≈0.85 t CO2/t cement process + fuel) 30–40 per cent lower
Clay calcination temperature Not applicable 700–850 °C
Key hydration products C-S-H, portlandite, ettringite C-A-S-H + carboaluminates
Chloride & sulphate resistance Good Superior
Production cost potential Baseline Equal or lower in most locations
Infrastructure compatibility Existing High (minor adaptations)

In India, commercial adoption has begun in earnest. JK Cement commenced the first commercial production of LC3 in the Indian subcontinent at its Mangrol plant in Rajasthan in 2025 under BIS standard IS 18189.
By early 2026, approximately 2,000 tonnes had been produced and sold, avoiding an estimated 500 tonnes of CO2. JK Lakshmi Cement followed with commercial launch of its Green PRO LC3 grade from the Jaykaypuram plant. As of mid-2026, two producers are supplying LC3 to the market. The first large-scale infrastructure application is the Noida International Airport (Jewar), where LC3 was used in the runway and a building complex, demonstrating full constructability and performance under demanding conditions. These early volumes are still small relative to national cement demand, but they mark the critical transition from pilot to commercial reality. Companies that scale capacity now will be positioned to capture both CCTS credits and emerging green-procurement demand.

Why the shift is accelerating
According to the World Bank’s State and Trends of Carbon Pricing 2026, direct carbon pricing now covers nearly 30 per cent of global greenhouse-gas emissions and generated more than US$107 billion in public revenue in 2025. The average global carbon price stands at approximately US$21 per tonne, although regional prices vary widely.
In Europe, the EU ETS price has traded near €80–85 per tonen in mid-2026. Free allocation for cement is being withdrawn in parallel with CBAM. European producers therefore face a clear signal: every tonne of avoided CO2 improves both compliance and competitiveness. Holcim has scaled calcined-clay production, including Europe’s first dedicated line at Saint-Pierre-la-Cour (France) and a second line in the Czech Republic (2026). Heidelberg Materials, Cementir (FUTURECEM) and others have commercialised low-clinker calcined-clay blends across multiple markets, showing that carbon-adjusted profitability is already reshaping capital allocation in the world’s most mature carbon market.India’s CCTS is now operational. Binding emission intensity targets apply to 186 cement facilities for FY 2025–26 and FY 2026–27. Average required reductions for integrated plants are modest (around 2.7 per cent by FY 2027), yet the direction is clear.
Trading of Carbon Credit Certificates is expected in the second half of 2026, with early prices likely in the `800–1,500 per tonne range. Plants that outperform targets can sell credits; those that underperform must buy them or face compensation. Cement is well positioned to be a net supplier of credits if clinker factor continues to fall through LC3 and other low-clinker systems.

Way forward for India
India starts from a strong baseline, world-class energy efficiency and a clinker factor already lower than the global average. The next competitive frontier is the deliberate reduction of process emissions through clinker substitution at scale. LC3 is uniquely suited to Indian conditions because suitable clays are widely distributed, the technology fits existing kiln and grinding infrastructure, and the resulting product can meet the performance demands of both infrastructure and building construction.
A practical national pathway contains five interlocking elements:

Standards and acceptance: Accelerated finalisation and promotion of BIS specifications for calcined-clay and limestone–calcined-clay cements will remove a key barrier to commercial uptake. Alignment with European practice (EN 197-5) can facilitate knowledge transfer and export readiness.
Supply-chain development: Investment in flash calcination capacity and systematic characterisation of regional clay deposits will secure reliable, low-cost feedstock. Existing rotary kilns can be adapted for initial volumes while dedicated calciners are built.
Incentive alignment: Part of variable compensation for plant managers, sales teams and senior leadership should be linked to emissions intensity reduction and to the volume of lower-carbon products (including LC3) sold. Without this link, traditional volume and cost targets will continue to dominate behaviour.
Product-level carbon accounting: Reliable measurement of emissions intensity at the individual cement grade level, supported by third-party verification where required, is essential for both CCTS compliance and credible green claims.
Demand-side pull: Green public procurement policies that specify maximum embodied-carbon thresholds for major infrastructure projects will create a predictable market for LC3 and other low-carbon cements, accelerating scale and cost reduction.
Companies that treat LC3 as a strategic product line rather than a niche offering will be better positioned to generate surplus Carbon Credit Certificates, capture any emerging green premium, and protect margins as carbon costs rise.

Organisational changes required
Technical capability alone is insufficient. Three organisational shifts are required.
Daily management: Emissions intensity must appear on the same daily and monthly dashboards as heat consumption, power consumption and utilization. Plant reviews should examine both conventional and carbon-adjusted results.
Incentives: A meaningful portion of bonuses for plant heads, technical teams and sales leadership should be tied to lower emissions intensity and successful commercialisation of LC3 and other low-carbon grades.
Commercial approach: Sales teams need clear volume and pricing targets for lower-carbon products, supported by technical service that helps customers specify and place the material correctly. Without commercial pull, excellent technical performance remains under-utilised.

Table 3. Three-stage roadmap to carbon-adjusted profitability
Time Horizon Priority Actions Expected Outcome
Next 12 months Add emissions intensity to plant dashboards; establish internal carbon price; initiate LC3 pilot production and customer trials Visibility and early organisational learning
12–24 months Revise incentive systems; scale LC3 and other low-carbon grades to key accounts; secure third-party verification capability People and sales aligned with carbon goals
24–36 months Embed carbon-adjusted metrics in board reporting and capital allocation; expand calcined-clay capacity Full system integration and competitive advantage

Questions senior leaders should ask
Boards can accelerate the transition by insisting on answers to a short list of questions:
• Is our carbon-adjusted profit improving, stable or declining relative to conventional EBITDA?
• Did recent volume growth improve or worsen our emissions intensity?
• What share of sales already comes from lower-carbon products, including LC3, and what is the trajectory?
• How exposed is our capital expenditure plan to rising carbon costs under CCTS and potential CBAM-related requirements?
• Do our incentive systems still reward only volume and cost, or have they been updated to include carbon performance?
Treating carbon with the same seriousness as energy cost or kiln utilization does not diminish operational excellence; it expands the definition of excellence to match the new competitive reality.

Looking ahead
By 2030 the gap between leading and lagging cement companies will not be decided by who records the lowest specific heat consumption. It will be decided by who delivers the strongest carbon-adjusted profits.
Absolute emissions may still rise as national production grows. That is not the issue. Companies that reduce intensity year after year and successfully sell cleaner products will pull ahead in both domestic and export markets. Those that do not will fall behind, even if their traditional efficiency numbers look strong.
Operational excellence built the Indian cement industry. It remains the foundation. It is no longer the complete picture. Carbon-adjusted profitability is the clearer measure of success.
LC3 is not a distant technology. It is available now. It cuts CO3 by 30–40 per cent, works with existing plants, and is already in commercial production in India. Companies that treat it as a strategic product, not a pilot, will protect their margins and generate tradable credits.
Leaders who act now will place carbon metrics on daily dashboards, link incentives to intensity reduction and LC3 sales, invest in calcined-clay capacity, and build commercial capability to sell lower-carbon products. They will shape the next chapter of the industry.

References

World Bank. (2026). State and Trends of Carbon Pricing 2026. Washington, DC: World Bank Group.
International Carbon Action Partnership (ICAP). (2026). India Carbon Credit Trading Scheme – Status and Coverage. Berlin: ICAP.
Ministry of Environment, Forest and Climate Change / Bureau of Energy Efficiency. (2025). Greenhouse Gases Emission Intensity Target Rules, 2025. New Delhi: Government of India.
Scrivener, K., Martirena, F., Bishnoi, S., & Maity, S. (2018). Calcined clay limestone cements (LC3). Cement and Concrete Research, 114, 49–56.
RMI. (2024). The Business Case for LC3. Rocky Mountain Institute.
European Commission. (2026). EU Emissions Trading System – Allowance Price Data and Free Allocation Phase-out Schedule. Brussels.
Holcim. (2025–2026). Scaling Calcined Clay for Sustainable Building – Corporate Updates on European and Latin American Capacity. Zurich: Holcim Ltd.
LC3 Project / EPFL. (2026). LC3 – A Guide to Best Practices for Scalable, Affordable and Sustainable Low-Carbon Building. Lausanne: École Polytechnique Fédérale de Lausanne.
Business Today / Industry Reports. (2026). First Large-Scale LC3 Application at Noida International Airport, Jewar. New Delhi.
NITI Aayog / Industry Analyses. (2026). Roadmap and Baseline Performance Indicators for the Indian Cement Sector. New Delhi.
Springer / Innovative Infrastructure Solutions. (2026). LC3 Systems: A Review of Chemistry, Performance, Durability and Sustainability toward Market Adoption.
Cementir Holding / Industry Sources. (2025–2026). FUTURECEM and Related Low-Clinker Technologies in Europe.
Climate Risk Horizons & Independent Analyses. (2026). Assessment of Emission Intensity Targets under India’s CCTS for Cement and Other Hard-to-Abate Sectors.
GCCA / TERI. (Various years). Decarbonization Roadmaps for the Indian Cement Industry.
EN 197-5:2021. Cement – Part 5: Portland-composite cement CEM II/C-M and Composite cement CEM VI. European Committee for Standardization.

Concrete

More Oversight Makes Cement Plants Less Safe

Published

3 days ago

August 28, 2026

admin

Dijam Panigrahi makes a counterintuitive but data-backed argument that routing every sensor alert through human approval does not make cement plants safer.

India’s cement industry has spent the last two years wiring kilns, mills and coolers with sensors and automated control systems, and the safety case for doing so is strong on paper. Contract workers still make up the majority of the industry’s workforce, and fatal accidents remain a recurring problem. The Indian National Cement Workers Federation has noted that around 83 per cent of workers in the sector hold precarious positions, a fact that resurfaced after an oxygen cylinder explosion killed three contract workers at a plant in Chhattisgarh.
Industry tallies compiled by IndustriALL found cement plants recorded at least seventeen accidents in one year with 21 workers killed, and ten accidents the following year with nine killed, most of them contract staff. Automated monitoring, in theory, closes that gap. A sensor never gets complacent and never skips a check because a shift is short staffed.
However, plants that respond by routing every anomaly reading to a person for approval are quietly building a system that fails the same way understaffing does. When operators receive dozens of flagged deviations a shift, most of them minor, they learn a simple lesson: the fastest way through the queue is to approve without reading closely. The safety benefit disappears, not because the technology failed, but because the humans supervising it adapted to the volume.

Why alerts get ignored
A study cited by manufacturing technology publisher Applied SmartFactory found more than 95 per cent of alarms in a semiconductor fab were low priority, and only about 4 per cent ever triggered an action, with just 100 out of 5,000 alarms accounting for 70 per cent of all alarm activity. The mechanism is the same whether the trigger is a vibration sensor or an AI model flagging a kiln temperature swing. Once the ratio of noise to signal crosses a threshold, workers stop treating the system as a decision aid and start treating it as a formality to clear.
The scale of AI deployment underway makes this more than a theoretical risk. Stanford’s 2026 AI Index Report found organisational adoption of AI has reached 88 per cent, even as documented AI incidents rose to 362 in 2025, up sharply from 233 the year before, according to analysis of the report. The Index also found only about a third of organisations have adopted a formal governance framework, with NIST’s AI Risk Management Framework cited by 33 per cent and ISO/IEC 42001 cited by 36 per cent.
Most manufacturers are deploying monitoring systems faster than they are building the judgment for when a flagged event actually needs a person’s attention. In India, plants run by JK Cement have begun pairing CCTV feeds with AI to define safe zones around heavy machinery, a promising direction that still depends on operators trusting and reading the alerts the system generates.

A three-tier model for cement plant
The fix is not less monitoring or more monitoring. It is classifying decisions by risk and by novelty, rather than treating human oversight as a single switch that is either on or off. A workable model sorts factory floor events into three tiers.
The first tier, proceed, covers deviations the plant has seen before that fall within known safe bounds, such as a kiln feed rate adjustment within an established range. These should run without a stop for approval, because routing them to a person only trains that person to click through.
The second tier, pause, covers events that are unusual but not yet dangerous, such as a vibration reading trending toward a limit or a fuel blend shifting outside its typical mix. These warrant a brief human check before the system proceeds, giving an operator the chance to apply judgment the model does not yet have.
The third tier, escalate, covers events that are both high risk and unfamiliar, such as a pressure reading combined with a temperature spike that has no close precedent in the plant’s history. These should stop the process entirely and require a decision from someone with the authority to shut down a line.

Who should set the threshold
Where these tiers get drawn matters as much as the framework itself. Threshold setting is frequently handed to the vendor supplying the monitoring software or to a plant’s IT department, both of which understand the technology but not the specific tolerances of a given kiln, mill or line. Operations staff, who know that a particular grinding unit runs hotter under monsoon humidity or that a calciner behaves differently after a refractory reline, are better positioned to calibrate what counts as routine on their own equipment.
Handing threshold ownership to operations does not remove IT or vendors from the process, but it puts the calibration decision closest to the people who live with its consequences on the floor.

Signals that oversight is actually working
A few concrete indicators reveal whether a monitoring setup is functioning as intended or simply providing the appearance of safety. The escalation rate over time is the first: a rate that stays flat or climbs slowly as operations mature is healthy, while one that spikes and then falls sharply often means operators have started overriding the system rather than engaging with it. Time to resolution is the second: escalations that take progressively longer to close suggest fatigue or confusion about ownership, not diligence. The third, and most telling, is how accurate the system’s own uncertainty estimates turn out to be, meaning whether events flagged as high risk actually correlated with real incidents, and whether events waved through stayed incident free. A system whose escalations do not track with actual outcomes trains operators toward the same complacency that unmonitored equipment produces.
None of this argues against automation in Indian cement manufacturing, where a labor structure built on contract work and a track record of serious accidents make better monitoring an urgent need. It argues for treating human oversight as a design problem with three distinct settings, rather than a single
dial turned up whenever a plant wants to look safer on paper.

About the author:
Dijam Panigrahi, Co-founder and COO, GridRaster, is a spatial computing platform for industrial enterprises and manufacturers.