Built Environment
Problem Overview: High usage of clinker in Indian cement industry
About 60% of cement CO₂ emissions comes from the calcination of limestone - the chemical decomposition of CaCO₃ into CaO (clinker) and CO₂. This reaction is endothermic and unavoidable within conventional Portland cement chemistry. Today, India’s average clinker factor is already comparable to global standards (~0.7), but has the potential to move towards ~ 0.5 through next-generation cement pathways.
While blended cement (blending SCMs like fly ash and GGBS in cement) now makes up over 70% of India's output, dominated by Portland Pozzolana Cement (PPC), there is a structural ceiling to this. Developers and structural engineers mainly steer towards OPC 53 grade (high clinker factor) for most high-cycle, high-load applications that represent the fastest-growing segment of India's construction market. Growth in high-performance structural applications could increase India’s clinker intensity.
Core Bottlenecks: Performance constraints and cost/infrastructure challenges for novel solutions
Several scaling challenges exist in solutions being explored today:
1. Compressive Strength Gain
Blended cements like PPC and PSC are already cost-effective, but take longer to gain compressive strength. Cycle time is essential for high-rise construction.
2. Quality Constraints
Variability in substitutes is quite wide. Blending creates performance constraints limiting usage (eg. 35% limits of fly ash in codes).
3. Lack of Standards
No BIS code for geopolymer concrete as a structural material. No codified design basis.
4. Retrofitting Needs
Novel solutions like LC3 need retrofitting and upfront capex investments.
Existing Approaches and Technology Readiness
Existing SCMs 2 heat pumps
Fly ash (limited substitution) & GGBS (limited supply)
Limestone calcined clay (LC3)
Blended cement reducing clinker with low-grade clays and limestone
Silicate based approach
Calcium silicates to replace limestone (~75% lower emissions)
Electrochemical
Replacing combustion kiln with electrochemical process
Where is the white-space for innovation?
The technologies and solutions above, which if implemented at scale, can enable wider replacement of clinker/cement across urban and rural housing and infrastructure like roads. There is a need for innovation on three fronts:
Science Breakthrough
Creating novel SCMs/ geopolymers/ blended cements which can give high performance including workability, setting time, strength, etc. Current activators also need to be made safer & eco-friendly for mainstream site use.
Engineering Innovation
Building modular infrastructure and bringing down the cost of production for these solutions.
Business model / Financial
Specifically for LC3: retrofitting, clay quality variation, lack of standardised testing and confidence are issues which need to be solved.
How we identify climate innovation opportunities?
- Decarbonization Roadmap for the Indian Cement Sector, TERI and GCCA India
- Tracking cement, IEA
- Guynn, J., & Kline, J. (2015, April). Maximizing SCM content of blended cements. In 2015 IEEE-IAS/PCA Cement Industry Conference.. IEEE.
- IPCC Cement Emissions Publication
- Calculated based on cost saved in cement production in India (blended vs ordinary cement)
- Calculated based on cost saved in cement production globally (blended vs ordinary cement)
- Calculated based on 15% clinker abatement in 2025, 20% clinker abatement in 2030
Last Updated On: June 5, 2026
Economic Potential
- India, 20258,300Mn USD[5]
- India, 203011,750Mn USD
- Global, 2025292,000Mn USD[6]
Impact Potential
- India, 202579 Mn Mt CO2e[7]
- India, 2030163 Mn Mt CO2e
- Global, 2025753 Mn Mt CO2e[8]
Waste
Air Pollution
p-ARL Score
9/12
Regulatory Outlook
Implemented
Spotlight for innovation in India
Research
IIT Madras and IITDelhi: Brought LC3 from lab to market
IIT Indore: Alkali-activated cement systems
Engineered SCM to enhance performance
Cement free geopolymers
Carbon-negative building blocks from crop residues & industrial waste