Concrete is responsible for 8% of global CO2 emissions, and CarbonStrong is raising $1.3M to chip away at that footprint. The seed round, backed by IAN Angel Fund, Rainmatter, Social Alpha, Spectrum Impact, and Full Circle Ventures, funds a technology that swaps out carbon-intensive cement for industrial byproducts like fly ash and steel slag.
The company’s proprietary activation process lets it replace 40–50% of cement in concrete mixes without sacrificing strength-actually making the material more durable and economical, per the startup. That pitch is aimed squarely at concrete producers and builders chasing net-zero targets, giving them a lower-carbon path that doesn’t require a complete overhaul of how they work.
