Cement, a fundamental component of modern infrastructure, is responsible for a significant portion of global carbon dioxide emissions.
However, there are existing solutions to mitigate this issue over the coming decades. This article explores the projected decline in cement demand and the rise of alternative materials through 2100.
Declining Demand and Shifting Dynamics
The demand for cement, which has historically grown alongside global development, is expected to decline. This is primarily due to China, the largest consumer of cement, approaching the end of its massive infrastructure and urban development phase.
As China’s demand decreases, the rest of the developing world will see increased demand as they build infrastructure. However, this growth will be slower and more spread out over time compared to China’s rapid expansion.
Replacing Portland Cement with Sustainable Alternatives
The use of Portland cement is not due to its exceptional qualities but rather its affordability and the abundance of limestone.
As carbon pricing and regulations increase the cost of cement, alternatives like engineered timber become more attractive.
Engineered timber offers comparable structural strength to reinforced concrete with a fraction of the mass, making it a carbon-negative option.
By diverting a portion of wood and paper products to engineered timber, a significant amount of cement can be displaced without increasing wood harvesting.
This approach also helps prevent anthropogenic biomethane from entering waste streams. The developed world’s forestry industries and the developing world’s vast forests can contribute to a sustainable forestry model that expands forest cover and sequesters carbon dioxide.
Cement displacement and decarbonization through 2100 by Michael Barnard, Chief Strategist, TFIE Strategy Inc.
Cement displacement and decarbonization through 2100 by Michael Barnard, Chief Strategist, TFIE Strategy Inc.
Geopolymers and Epoxies: Emerging Alternatives
Geopolymers and epoxies are other promising alternatives to traditional cement. These materials, derived from industrial and agricultural waste streams, offer comparable strength and durability.
While they still require reinforcement, their use can significantly reduce the demand for cement.
Finite element analysis software and generative architecture tools enable more efficient and material-saving designs.
These technologies, accessible worldwide, will play a crucial role in reducing the amount of cement used in construction projects, particularly in the developing world.
Advanced Materials: Fiberglass and Carbon Fiber
Fiberglass and carbon fiber offer additional avenues for reducing cement demand. Fiberglass can replace steel mesh in reinforced concrete, leading to lighter structures and smaller foundations.
Carbon fiber can further reduce the need for both steel and concrete in structural components. These materials, coupled with advanced software, present significant opportunities for material savings and decarbonization.
Repurposing existing buildings instead of demolishing them is another crucial lever in reducing cement demand. In the developed world and China, many existing buildings can be renovated and reused for different purposes.
Additionally, technologies are emerging to extract and reactivate cement from recycled concrete, offering a potential solution for reducing the need for new cement production.
Carbon Capture and Sequestration: A Limited Role
While carbon capture and sequestration (CCS) may be economically viable for the cement industry, it is unlikely to be a major solution compared to the alternatives mentioned above.
The geographic mismatch between CCS facilities and cement production sites, as well as the long-term economic challenges of creating and maintaining waste streams, limit the potential of CCS in this sector.
The future of cement decarbonization lies in a combination of reduced demand, the adoption of sustainable alternatives like engineered timber and geopolymers, and the optimization of construction processes through software and advanced materials.
While challenges remain, the growing momentum behind these solutions offers a promising path towards a more sustainable and low-carbon construction industry.