Anhydritbaserade

Anhydritbaserade refers to materials or products that use anhydrite as their primary binding agent. Anhydrite is a mineral composed of calcium sulfate, CaSO4, which is anhydrous, meaning it contains no water. This is in contrast to gypsum, which is a hydrated form of calcium sulfate with the chemical formula CaSO4·2H2O.

Anhydrite-based binders are produced by heating gypsum at temperatures typically between 150-180°C. This process drives off most, but not all, of the water of crystallization, resulting in a material that can rehydrate and harden when mixed with water. The resulting anhydrite binder is often referred to as "natural anhydrite" or "plaster of Paris" depending on the purity and processing.

Anhydrite-based materials are known for their rapid setting times and high early strength development. They also exhibit low shrinkage compared to cement-based materials, which can lead to more stable constructions. Due to their solubility in water, anhydrite-based products are generally not suitable for exterior applications or areas exposed to prolonged moisture. They find common use in interior construction, such as self-leveling floor screeds, plasters, and precast elements where rapid hardening and good dimensional stability are desired. The term "anhydritbaserade" is often used in technical contexts, particularly in European languages, to describe these specific types of calcium sulfate-based construction materials.