Kevytbetoni

Kevytbetoni, or lightweight concrete, is a cementitious material that contains a network of air voids. The air voids markedly reduce density and thermal conductivity compared with normal concrete. It is commonly produced by incorporating a foaming agent and/or aluminium powder into the cementitious mix, which creates countless tiny air bubbles. The fresh mix can be cast into blocks, panels, or sprayed and then cured to form a solid but lightweight material.

Two main production routes exist: autoclaved aerated concrete (AAC) and non-autoclaved foam concretes. AAC is formed into blocks or panels and then steam-cured under pressure in an autoclave to achieve strength and stability. Non-autoclaved foams cure at ambient temperature or with steam without the autoclave, yielding slightly different properties and densities.

Kevytbetoni has lower density than ordinary concrete, with good fire resistance and sound insulation, and high thermal insulation, contributing to energy-efficient buildings. It can be cut and drilled similarly to other masonry materials. However, its strength is lower than dense concrete, so it is typically used for non-loadbearing walls or as a cladding or partition material combined with structural elements. It is widely used in residential and commercial construction for walls, floors, and roof panels, and is often supplied as blocks or precast panels.

Care and installation require appropriate sealants for joints, and moisture management is important since the material is porous. Finishes and bonding systems should be compatible with its porosity.

Standards and sustainability: Kevytbetoni is produced under European and regional standards for aerated concrete masonry units and is valued for its low weight and insulating properties, contributing to lighter structures and energy-efficient buildings.