Concrete
Environmental Benefits of Using Waste Glass as Pozzolana
Published
3 years agoon
By
admin
Dr SB Hedge, Professor, Jain University and Visiting Professor, Pennsylvania State University, United States of America, discusses the environmental benefits of using waste glass as Pozzolana in this concluding part of the article.
Pozzolanic properties of waste glass refer to its ability to react with calcium hydroxide in the presence of water to form cementitious compounds. This reaction, known as the pozzolanic reaction, contributes to the strength and durability of cementitious materials.
Findings based on the investigation on the Pozzolanic properties
Here are some details on the pozzolanic properties of waste glass and examples of its usage:
Amorphous Silica Content: Waste glass typically contains a significant amount of amorphous silica, which is a key factor in its pozzolanic activity. Amorphous silica has a high
surface area, allowing it to react readily
with calcium hydroxide and form additional cementitious compounds.
Reactivity and Fineness: The reactivity of waste glass depends on factors such as its chemical composition, particle size distribution, and surface area. To enhance its pozzolanic reactivity, waste glass is often ground to a fine powder. Increased fineness improves the contact between waste glass particles and calcium hydroxide, facilitating the pozzolanic reaction.
Pozzolanic Reaction Products: When waste glass reacts with calcium hydroxide in the presence of water, it forms additional cementitious compounds, such as calcium silicate hydrate (C-S-H) gel. The C-S-H gel contributes to the strength and binding properties of the
cementitious matrix.

Examples of Usage
Partial cement replacement: Waste glass can be used as a partial replacement for cement in concrete production. Typically, a portion of the cement is substituted with finely ground waste glass powder. This reduces the overall cement content while maintaining or improving the mechanical properties and durability of the concrete.
Glass powder addition in concrete mixes: Waste glass powder can be directly added to concrete mixes as an additional pozzolanic material. It acts as a supplementary cementitious material (SCM) alongside other pozzolanic materials like fly ash or silica fume. This combination enhances the reactivity and overall performance of the concrete.
Glass aggregate in concrete: In addition to using waste glass as a pozzolanic material, it can also be used as a fine or coarse aggregate in concrete production. By incorporating waste glass aggregates, both the pozzolanic and aggregate properties of the glass are utilised. This approach enhances the sustainability of concrete while maintaining structural integrity.
Glass fibre reinforcement: Waste glass fibres can be used as reinforcement in cementitious composites. The glass fibres provide tensile strength and improve the overall performance of the concrete. This application is particularly useful in construction elements requiring enhanced durability and crack resistance.
Glass as pozzolanic additive in mortars: Waste glass can be used as a pozzolanic additive in mortar mixes. Mortars containing waste glass exhibit improved workability, increased strength and reduced permeability. This makes them suitable for applications such as plastering, masonry and tile adhesives.
Waste glass possesses pozzolanic properties due to its high amorphous silica content. By utilising waste glass as a pozzolanic material, its environmental impact can be reduced while enhancing the performance and sustainability of cementitious materials.
The examples provided demonstrate the versatile usage of waste glass in cement and concrete applications, contributing to a more sustainable construction industry.

Environmental Benefits
The utilisation of waste glass as a pozzolanic material in cement production offers significant environmental benefits. Here is a detailed account of these benefits:
Waste reduction and recycling: Waste glass, if not properly managed, poses a significant environmental challenge. By using waste glass as a pozzolanic material, it is diverted from landfills or incineration, reducing the need for new disposal sites and minimising the environmental impact associated with glass waste. Recycling waste glass as a pozzolana promotes a circular economy by converting it into a valuable resource.
Conservation of natural resources: The incorporation of waste glass in cement production reduces the need for virgin raw materials, such as limestone or silica. By substituting a portion of cement with waste glass, natural resources are conserved, including the energy and water required for extraction and processing of raw materials. This conservation helps in preserving natural ecosystems and reducing the overall ecological footprint.
Energy savings and emissions reduction: The production of cement is energy-intensive and contributes to greenhouse gas emissions, primarily carbon dioxide (CO2). By using waste glass as a pozzolanic material, the cement content in concrete is reduced, resulting in lower energy consumption and CO2 emissions during cement manufacturing. This reduction in energy usage and emissions contributes to mitigating climate change and achieving sustainability goals.
Reduced landfill space and leachate generation: When waste glass is disposed of in landfills, it occupies valuable space and can contribute to environmental concerns. Glass waste in landfills may also produce leachate, potentially contaminating soil and groundwater. Utilising waste glass as a pozzolanic material reduces
the amount of glass waste sent to landfills, alleviating the pressure on waste management infrastructure and minimising the associated environmental risks.
Improved air quality: Cement production is associated with the release of pollutants, including dust, particulate matter, and potentially harmful gases. By replacing a portion of cement with waste glass, the production of cementitious materials can be optimised. The use of waste glass as a pozzolana reduces the overall emissions of particulate matter and improves air quality in and around cement plants, promoting a healthier environment for nearby communities.
Enhanced durability and reduced maintenance: Concrete incorporating waste glass as a pozzolanic material exhibits improved durability and reduced permeability. This translates into longer service life for concrete structures, reduced maintenance requirements, and decreased need for repairs or replacements. By extending the life of concrete, the environmental impact associated with new construction projects is minimised.
Waste Glass Addition
The addition of waste glass to concrete can significantly improve its performance in several ways. Here are the key ways in which waste glass enhances the performance of concrete:
- Increased strength and durability: The incorporation of waste glass as a pozzolanic material in concrete leads to the formation of additional cementitious compounds. These compounds, such as calcium silicate hydrate (C-S-H) gel, contribute to the strength and durability of the concrete. The pozzolanic reaction between waste glass and calcium hydroxide results in denser and more compact concrete, improving its compressive and flexural strength.
- Reduced permeability: Concrete containing waste glass exhibits reduced permeability to water and other potentially harmful substances. The pozzolanic reaction of waste glass results in the formation of a refined pore structure within the concrete matrix. This refined pore structure restricts the movement of water and other aggressive agents, enhancing the concrete’s resistance to moisture ingress, chemical attack, and freeze-thaw damage.
- Enhanced chemical resistance: The pozzolanic reaction of waste glass in concrete leads to the formation of calcium silicate hydrate (C-S-H) gel, which provides improved chemical resistance. This resistance makes the concrete less susceptible to chemical degradation caused by substances such as sulphates, chlorides and acids.
Concrete with waste glass as a pozzolanic material exhibits better long-term performance in aggressive environments. - Improved workability and cohesion: The addition of waste glass as a pozzolanic material can enhance the workability and cohesion of concrete. Due to the fine particle size and pozzolanic nature of waste glass, it acts as a filler material, improving the packing and lubrication of the concrete mixture. This improved workability allows for easier placement, consolidation, and finishing of
the concrete. - Mitigation of alkali-silica reaction: Alkali-Silica Reaction (ASR) is a chemical reaction that can occur between certain reactive silica minerals in aggregates and the alkalis present in cement. This reaction can lead to expansive cracking and deterioration of concrete. Waste glass, being an inert material, can act as a mitigating agent for ASR by replacing some of the reactive silica in the concrete mix.
- Sustainability and eco-friendliness: In addition to performance improvements, the utilisation of waste glass in concrete contributes to sustainability and eco-friendliness. By incorporating waste glass as a pozzolanic material, the consumption of cement is reduced, resulting in CO2 emissions associated with cement production. This reduction in CO2 emissions aligns with environmental goals and contributes to a more sustainable construction industry.
Challenges and Considerations
The utilisation of waste glass as a pozzolanic material in cement production does pose some challenges. Proper processing and grinding of waste glass to achieve optimal fineness is crucial to ensure its reactivity. The potential presence of impurities in the waste glass, such as metals or contaminants, requires careful selection and pre-treatment. Additionally, the impact of incorporating waste glass on the fresh and hardened properties of concrete should be evaluated to ensure compatibility with specific project requirements.
Research and Industry Initiatives
Ongoing research and industry initiatives are focused on optimising the use of waste glass as a pozzolanic material. Studies explore various methods of processing and grinding waste glass to enhance its reactivity and maximise its utilisation. Additionally, there is a scope to investigate the influence of waste glass characteristics, such as particle size, composition and treatment, on the properties of concrete. These efforts aim to develop guidelines and standards for incorporating waste glass in cement production.
Conclusion
The use of waste glass as a pozzolanic material in cement production offers a sustainable solution to address environmental concerns associated with both waste glass disposal and cement manufacturing. By harnessing the pozzolanic properties of waste glass, cement producers can reduce their carbon footprint, enhance concrete performance, and contribute to a more circular economy.
The addition of waste glass as a pozzolanic material significantly enhances the performance of concrete. The improvements include increased strength and durability, reduced permeability, enhanced chemical resistance, improved workability and cohesion, mitigation of alkali-silica reaction and sustainability benefits. By embracing waste glass in concrete production, the construction industry can create more resilient and eco-friendly structures while effectively utilising a valuable waste material.
Further research, collaboration and implementation efforts are essential to fully exploit the potential of waste glass as a valuable resource.
References
- Utilisation of Waste Glass Powder in Concrete by P. Manoj Kumar, K. Sreenivasulu, and M. Srinivasulu Reddy, International Journal of Innovative Research in Science, Engineering and Technology, 2013.
- Recycling of Waste Glass as a Partial Replacement for Fine Aggregate in Concrete Mix by W. A. Rahman, M. A. S. Al-gahtani, and M. A. K. El-Kourd, Journal of King Saud University – Engineering Sciences, 2010.
- Mechanical and Durability Properties of Concrete Containing Glass Powder as Partial Replacement of Cement by A. Shayan and R. Xu, Construction and Building Materials, 2004.
- Properties of Glass Concrete Containing Fine and Coarse Glass Aggregates by Z. Feng, S. Xie, and Y. Zhou, Journal of Materials in Civil Engineering, 2011.
You can find part one in the August issue of Indian Cement Review.
ABOUT THE AUTHOR
Dr SB Hegde is a Professor at Jain University and a Visiting Professor at the Pennsylvania State University, United States of America.
Concrete
CarbonStrong Raises Rs 125 Million To Scale Low Carbon Cement Tech
To build capacity of 100,000 tonnes a year
Published
2 days agoon
August 28, 2026By
admin
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.
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
2 days agoon
August 28, 2026By
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.
CarbonStrong Raises Rs 125 Million To Scale Low Carbon Cement Tech
Protect Your Margins
More Oversight Makes Cement Plants Less Safe
The biggest gap arises from inconsistent leadership
The Future of Vertical Material Handling
CarbonStrong Raises Rs 125 Million To Scale Low Carbon Cement Tech
Protect Your Margins
More Oversight Makes Cement Plants Less Safe
The biggest gap arises from inconsistent leadership

