Aftercement

At 573 °C the quartz in concrete undergoes a phase transition and changes volume — the matrix destroys itself from within. That is why THERM-D contains no quartz aggregate. Potassium silicate chemistry and non-quartz fillers: the matrix keeps working where concrete has already cracked.

Application

Refractory linings, chimneys and flues, structural fire protection, metallurgy.

Hardened Portland cement paste is built from calcium hydroxide and C-S-H phases — both dissolve in acid. Below pH 6 the matrix starts to leach away, quite literally grain by grain. A geopolymer is an aluminosilicate network with no free calcium hydroxide: there is nothing left to carry off. CHEM-D works across the entire pH 2–13 range.

Application

Chemical, mining and food industry — tanks, bunding, foundations. Wherever concrete is replaced every two to four years.

EN 206 covers chemical attack up to class XA3 — roughly 6,000 mg/l of sulfates. Above that the standard simply has no answer. In a sewer, sulfate-reducing bacteria convert hydrogen sulfide into sulfuric acid at the crown; it attacks the portlandite and forms ettringite, which expands the matrix from within. No portlandite, no ettringite — in HYDRO-D the mechanism of destruction is absent altogether.

Application

Treatment plants, sewers, reservoirs. Biogenic sulfuric corrosion — the most expensive enemy of water infrastructure.

A floor does not wear down in depth, it wears at the surface. In C30/37 the cement paste around the aggregate is the softer component: it abrades first, the grains are exposed and break out, and the forklift route turns into a rut. UHPC-D builds a dense matrix above 60 MPa in which binder and aggregate wear at the same rate — the surface stays flat.

Application

Industrial floors under heavy traffic, wear-resistant screeds, machine foundations.