Ca₂O₁₀Si₂TiV

Architectural potential

A titanium-vanadium-doped calcium silicate, fired at 1100 °C, carrying the solar-absorber chemistry of a V-doped titanate on a cement-register binder. At 50 MPa the compressive performance sits at the non-structural end of the binder range, which forbids load-bearing walls but opens up a specific placement: thermal-absorber surface panels for south-facing trombe walls, warm-toned cladding inserts on solar-gain façades, and screed-layer toppings for hypocaust-style floor slabs where the body is meant to absorb visible light into itself rather than reflect it. Against Portland cement the embodied CO₂ is nineteen per cent lower, and the visible-absorber chemistry shifts the role from binder to collector — a layer that pays for itself by taking solar gain into the thermal mass behind it rather than bouncing it into the room. The very low bulk density (0.348 g/cm³) is the tell: this is a foamed or aerated cast, not a dense pour, so its natural scale is the insulating-absorber panel, not the structural screed. The caveat is cost — €27.98 per 1 kg batch is high for a low-CO₂ cement substitute, and the absorber chemistry earns its specification only where the thermal argument is actually being made.

Material character

A warm white-grey body with a faintly greenish cast from the vanadium-titanate phase — distinct from the purely neutral calcium-silicate whites in the atlas. At 0.348 g/cm³ the 120×120×200 mm block is unexpectedly single-handed in the lift, close in hand-feel to a softwood offcut rather than a dense masonry unit — the aerated cast reads in the weight before it reads in the eye. Surface cold-pressed and chalky, with a gentle open porosity that catches raking light as a soft dusting. Edges slightly crumbling, powdery at the kerf. Against an ordinary calcium-silicate block the body is visibly lighter and the absorber tint shifts it warmer under full sun.