AutoclavedAeratedConcrete(AAC)
Known as AAC or Gasbeton. Extremely light mineral material composed 80% of trapped air in a siliceous mineral matrix. Combines the load-bearing properties of masonry with the thermal performance of pure insulation.
The millimetric calibration of blocks allows the use of infinitely thin adhesives, improving thermal and structural homogeneity of the wall.
Autoclaved Aerated Concrete (AAC) overturns the concept of heavy masonry. It is a monolithic material that simultaneously performs the functions of load-bearing structure and excellent thermal insulation, without the aid of additional insulation layers.
The mix is composed of siliceous sand, cement, lime and water. The secret lies in the addition of aluminium powder, which reacts alkalinically, developing hydrogen gas and doubling the volume of the mixture. After cutting, the blocks are cured in a saturated-steam autoclave (190 degrees C at 12 bar). This process chemically transforms the binders into tobermorite, a silicate mineral that confers absolute dimensional stability. The final product has virtually zero post-production shrinkage, unlike traditional fired bricks.
The closed-pore structure makes AAC an excellent thermal insulator. Laying is done with adhesive mortar applied with a notched trowel (2-3 mm thick): this eliminates the thermal bridge typical of the thick mortar joint of traditional brickwork. A 40 cm block alone achieves thermal transmittance U values below 0.20 W/m2K, satisfying nZEB regulations without additional layers.
Standards
European and international references applicable.
Physical properties
Usage environment
Dedicated fixings (long plugs specific for AAC or chemical anchors) are mandatory. Protect the base from capillary moisture: always install a damp-proof course at foundation level.
Documented applications
TAV. DSingle-layer cladding
External envelope achieving nearly-zero energy (nZEB) without additional external insulation.
Partitions and dividers
Internal walls in thin blocks (8-10 cm), fast to lay, flat and highly sound-absorbing.
Thermal bridge correction
Special pieces, lintels and U-blocks to thermally break R.C. columns and slab edges.
Fire-rated walls (REI)
Compartmentalisation of factories and warehouses thanks to the totally inorganic and non-combustible nature.
Thermal Conductivity Lambda (W/mK) — shorter bar = better insulation
TAV. EThermal conductivity lambda (W/mK): the lower the bar, the less heat is transmitted. A single 40 cm AAC block achieves a U-value below 0.20 W/m2K, satisfying the most stringent nZEB requirements without any additional cladding layer.
Used in these systems
TAV. SOperational documents from this sheet
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