In an industry striving to significantly lower its carbon footprint, the concrete sector faces substantial challenges in aligning with the 2030 and 2050 climate-action goals. Cement, the key ingredient in concrete, is a major contributor to global carbon dioxide (CO2) emissions, accounting for as much as 8% of the total emissions.
CarbonCure Technologies is at the forefront of addressing these environmental concerns through innovative technology. Their core technology injects captured CO2 into fresh concrete, which increases cement hydration efficiency via mineralization. The mineralization process allows producers to achieve equivalent strengths with reduced cement content, meaning their concrete designs are less carbon intensive than typical mixes. However, CarbonCure’s quest to answer the call for sustainable solutions doesn’t stop there.
CarbonCure has developed a method to treat reclaimed water—a byproduct of concrete production that is typically dumped—with CO2, further enhancing sustainability of a mix. To validate the performance of this emerging technology, CarbonCure worked together with CTLGroup, leveraging their expertise in third-party testing.
Reclaimed water, produced from cleaning concrete trucks and mixers, is typically seen as a waste product. This water contains fine particles of sand and suspended solids from cement hydration, which traditionally limit its reuse in new concrete due to variability in chemistry and properties. Reusing this water in concrete production has been limited because of the negative impacts on material performance, which intensify with increasing concentrations of suspended solids and their varying ages.
Injected CO2 transforms the cement in reclaimed water slurry into a predictable resource, reducing the virgin cement and water requirements in new concrete mixes. Preliminary data indicate that producers can enable the savings of up to 10-25lb of carbon per cubic yard of concrete.
To confirm these findings, CarbonCure Technologies retained CTLGroup who, with their extensive R&D experience and ASTM/AASHTO accreditations, was able to deliver reliable data to validate CarbonCure’s innovative approach. Given the lack of standardized specifications for emerging technologies in the concrete industry, it was important to select a collaborator that stayed on the forefront of materials technology.
CTLGroup utilized the ASTM C1709 guide, which provides a framework for evaluating the performance of new concrete technologies. CTLGroup developed a comprehensive testing matrix to compare various test mixtures to control mixtures, meticulously planning and executing physical tests in their laboratories.
The results from CTLGroup’s testing were promising. Test mixtures incorporating reclaimed water and captured CO2 demonstrated an increase in concrete strength by 5% to 14% while reducing the cement content by up to 10%.
These findings showcased the potential of CarbonCure’s technology to enhance sustainability in concrete production. Alex Hanmore, Director of Technical Customer Solutions at CarbonCure, praised CTLGroup’s professionalism and attention to detail, stating, “Our experience with CTLGroup has been very positive. We felt that their service was well worth the investment, and data was managed carefully, effectively, and thoroughly.”
The teamwork between CarbonCure and CTLGroup demonstrates how industry collaborations can drive technological innovation and environmental stewardship. The successful validation of their reclaimed water technology paves the way for broader adoption, supporting the industry’s transition towards more sustainable practices.
Photos provided by CarbonCure Technologies