Carbon-cured concrete refers to precast or ready-mix concrete cured by exposure to CO2 in a controlled chamber rather than by conventional water hydration, which chemically fixes CO2 into the material while accelerating strength gain. The patent record here is narrower than the broader CO2 mineralization research field: it is concentrated almost entirely in the C04B cement/ceramics IPC class and centred on curing equipment and process claims rather than on novel binder chemistry. Most of the highest-cited records describe curing chambers and dosing equipment, meaning the commercially proven claim territory is process and hardware, with formulation chemistry trailing behind.

Filing activity is concentrated among a small group of assignees, with several Japanese firms showing the strongest co-filing relationships in the dataset — the largest co-assignee pair shares 15 families together. That said, recent-year momentum for these leading assignees has dropped to zero filings with year-over-year declines around -100%, suggesting the core curing-equipment claim space is now largely settled rather than actively being expanded. Newer entrants, including university-affiliated filers, are more visible in adjacent formulation work rather than in the core equipment cluster.

The trend data shows filings rising from zero in 2017 to a peak of 28 in 2024, with a midpoint of 17 in 2022, and no further growth visible through the 2025–2026 window in the dataset. Because patent publication lags actual filing by roughly 18 months, the most recent one to two years in any dataset will always look artificially quiet, so a flat or falling count for 2025–2026 should not yet be read as declining inventive activity. A clearer read on whether the field is still growing will only be available once those recent filings finish publishing.

The core curing-chamber and cement-formulation claims are dense, but adjacent IPC areas remain thin: separation-process integration (7 families), catalytic acceleration (4 families), general mixing equipment (3 families) and pavement-specific applications (2 families) are all represented but far from saturated compared with the 134-family core in C04B. That thinness points to open claim territory in tying specific CO2 capture or waste-feedstock streams directly to a curing process, rather than claiming the chamber or the base concrete mix on their own. Waste-stream-specific formulations, such as calcium carbide residue blends, also show only isolated precedent so far.

US11713279B1, assigned to United Arab Emirates University, claims a system and method combining calcium carbide residue (CCR) as a cement replacement with an accelerated carbonation curing chamber step. It blocks that specific pairing — CCR-OPC blended concrete fed into a carbonation chamber as an integrated system — but it does not block carbonation curing generally, since that space is already covered by older, more heavily cited Japanese and Korean equipment patents. Developers using a different cement-replacement feedstock through the same or a different carbonation process would likely sit outside this claim's scope, though they should still check the older equipment-patent cluster for overlap.