Product · Materials Science
Product · InnDex 62 · Evidence provided · High specification risk
Cement-free concrete using slag and CO₂ carbonation curing instead of Portland cement.
CarbiCrete addresses concrete's largest carbon source—Portland cement calcination—by substituting blast-furnace slag and curing with captured industrial CO₂ in a pressurized chamber. CO₂ carbonates the slag matrix to form binding calcium carbonates, permanently sequestering the gas. Commercial production launched Q4 2023 at ~900k units/year; ASTM-verified EPD (Nov 2024) shows 20× lower GWP than conventional concrete.
CarbiCrete substitutes blast-furnace slag for Portland cement and cures the product under pressurised industrial CO₂, which reacts with the slag matrix to form calcium carbonates that permanently lock the gas into the solid — so the carbon is sequestered rather than stored. An ASTM-verified EPD from November 2024 shows a 20-times reduction in GWP against conventional concrete; commercial production of CMUs and pavers launched in Q4 2023 at roughly 900,000 units per year. That combination of verified EPD, third-party testing, and active production distinguishes this from many low-carbon concrete claims that exist primarily in lab or pilot form — one provided data point at inndex 62 is honest about scale, not a red flag about verifiability. The constraints are structural in both senses: the technology is confined to precast products (CMU, pavers) and has not been demonstrated for ready-mix or cast-in-place applications, which limits where it fits in a typical building programme; supply chain requires co-location of slag and industrial CO₂ off-gas, making it geography-dependent; and the pressurised curing chamber is a capital and operational commitment that does not sit inside a conventional concrete plant. Long-term durability data beyond the initial commercial period is accumulating but not yet available at the 50-year horizon that structural specifications demand. For wall masonry and paving on projects within reach of the supply chain, this is a credible near-term embodied-carbon lever with real commercial production behind it; confirm local supply, request the EPD, and treat durability over multi-decade timescales as a watch item requiring ongoing monitoring.
Manufacturing scale and EPD verification (Climate Earth, ASTM) are credible and recent (2024–2025). However: (1) CO2 source is industrial off-gas (e.g., steel mill tail gas), not DAC—this is an important carbon-accounting boundary that affects the climate story in scaled-out scenarios where off-gas becomes scarce or distributed. (2) Product range appears limited to precast masonry and pavers; no evidence of ready-mix, cast-in-place, or structural beam production yet. (3) Single operational facility limits generalizability. (4) No published data on long-term durability, carbonation resistance, freeze-thaw performance, or fire ratings. (5) Pressure curing process energy/cost not detailed in public materials. (6) Slag sourcing tied to steel industry cycles and geography—supply resilience unaddressed.
#decarbonization #concrete #industrial-symbiosis #carbon-utilization #slag-valorization