The California Construction & Industrial Materials Association (CalCIMA), a trade organization representing the lion's share of concrete production in California, has unveiled a roadmap for achieving net-zero concrete by 2045. This roadmap, though primarily focusing on California, seamlessly aligns with broader national and international efforts to decarbonize the concrete industry.

In this short article, we summarize CalCIMA’s roadmap and the policy recommendations introduced in its report. We also highlight the areas where CarbonCure’s technologies intersect with and support the decarbonization pathways outlined by CalCIMA.

About CalCIMA

CalCIMA is a trade association for the construction and industrial material industries in California, which includes aggregate, industrial mineral, ready mixed concrete, and asphalt producers. It represents about 70 producer member companies that include over 250 production sites in every county of California and over 70 suppliers and service providers to the industry.

In June 2023, CalCIMA released a report intended to help inform policymakers and the public about the opportunities for California concrete producers to achieve net zero carbon concrete. It assesses what opportunities are most achievable, which ones have the most impact, and the time frame for achieving them.

Decarbonizing the Concrete Industry

To attain net zero concrete in California, CalCIMA recognizes that a flexible strategy is essential, considering challenges like existing regulations, limited raw material supplies, and the unique dynamics of the industry. 

CalCIMA also acknowledges there is no silver bullet to decarbonizing the concrete industry. Like CarbonCure, CalCIMA believes that the solution doesn't lie in a single magic fix. Instead, a multifaceted approach that actively involves all players in the cement-concrete-construction value chain is crucial. Five pathways to decarbonization have been identified.

1. Performance-Based Specifications

Prescriptive-based specifications for concrete are restrictive, often hindering the use of mixes with lower carbon footprints. 

By moving towards performance-based specifications, concrete producers gain the flexibility to innovate and produce low-carbon products. CarbonCure’s technology, which aims to lower the carbon footprint without compromising performance, is evidence of the potential of this pathway.

CarbonCure Supports Performance-Based SpecificationsConcrete specifiers — architects, engineers, consultants — play the most important role in embodied carbon reduction and removal: encouraging the inclusion of low carbon technologies like CarbonCure in their specifications. Learn More

2. Use Less GHG Intense Raw Materials 

Most of concrete's carbon footprint can be attributed to its ingredients, primarily cement. The two-pronged pathway recommended here involves expanding the use of lower carbon cement and incorporating Supplementary Cementitious Materials (SCMs). 

Biggest Impact to GHG Emissions is Cement ReductionIn typical mixes listed by the NRMCA industry-standard EPD, cement contributes about 80% of the total GWP score.   The most significant contribution we can make to decrease the Global Warming Potential (GWP) of concrete lies in minimizing its cement content. This can be achieved by optimizing the mixture composition, incorporating alternative binders, and leveraging sustainable additives and innovative solutions like CarbonCure.

3. Optimize Design, Waste Reduction, and Circularity

A significant reduction in emissions can be achieved by optimizing concrete use, curbing waste, and championing recycling initiatives. 

CarbonCure Reclaimed Water technology is an exciting development in this space. It revitalizes the cementitious content and water in a concrete producer’s slurry tank and turns them into valuable upcycled resources that can be reused in high-quality concrete. 

Stephen Hay, General Manager at Trio Ready-Mix on Vancouver Island shared his experience, “For over 30 years, the concrete industry has been challenged to find an effective solution for reclaimed water. Because CarbonCure standardizes and stabilizes the cementitious fines in the reclaimed water, we get repeatable, consistent results that allow us to gain maximum value from the cementitious fines in terms of strength. It almost acts as a supplementary cementitious material.”

Other innovations mentioned by CalCIMA include smart crushing technology, which separates unused cement stone from the concrete rubble during the crushing process so it can be used again in fresh concrete.

4. Increasing the GHG Efficiency of Concrete Operations

Manufacturing and transportation account for approximately 10% of total embodied emissions in concrete. By automating manufacturing processes and reducing transportation emissions, the industry can further its decarbonization goals. 

5. Increase the Recarbonation — or CO2 Uptake — Potential of Concrete

Recarbonation, wherein CO₂ is absorbed by concrete structures, offers a unique opportunity to absorb CO₂ over time but requires development of standards to ensure safety and durability as well as methods for measuring the amount of CO₂ captured in the concrete over time.

Unlike typical atmospheric recarbonation, CarbonCure injects CO₂ into fresh concrete which not only reduces the carbon footprint but also enhances the concrete's compressive strength, so less cement is required in the mix design.

Read concrete producers’ experiences with CarbonCure’s technologies.

Source: CalCIMA

9 Policy Recommendations from CalCIMA

At the end of the report, CalCIMA highlights nine key policy recommendations, underscoring the importance of adapting to new technologies and fostering innovation. 

Notably, among the recommendations is a call to make way for innovative technologies like CarbonCure that can help speed up the transition to low-carbon concrete solutions. 

1. Advocate for performance-based concrete specifications, allowing producers the flexibility to innovate with new technologies and create low carbon mix designs.
2. Introduce incentives to lower the costs of new low-carbon concrete technologies like CarbonCure.
3. Offer public support for industry investments in decarbonizing production infrastructure.
4. Boost market demand for low carbon concrete with high Supplementary Cementitious Materials (SCMs) or other technologies like CarbonCure through incentives and education.
5. Support infrastructure upgrades at batch plants to facilitate greater use of low carbon innovations.
6. Develop partnerships to form circular supply chains incorporating demolished concrete or recycled material from washwater, enhancing recarbonation.
7. Adjust construction regulations to maximize concrete's recarbonation potential.
8. Establish public-private research and development collaborations for sourcing alternative raw materials.
9. Strengthen collaboration between concrete producers and stakeholders to optimize projects' environmental impact.

Overall, the objective is clear: to create a conducive environment for industry stakeholders to adapt to decarbonization, form circular supply chains, and collaborate on reducing the environmental impact of projects. 

Read our comprehensive summary of the CalCIMA report in our short white paper or download the full report from CalCIMA.

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