M C Limbachiya(1) and C A Fudge(2)
(1) Kingston University- London, UK
(2)Aircrete Products Association, UK

Currently in the UK, aircrete (autoclaved aerated concrete) masonry units are usually produced with a minimum declared compressive strength of 2.9N/mm2 (measured to EN772-1) and a minimum density of 400kg/m3. The minimum values were based historically on the limits given in product standards and those within structural design documents supporting building regulations. With the growing demand for buildings with low CO2 emissions, a new breed of block is required with an enhanced thermal conductivity.
This paper reports part of an extensive research project carried out by the Kingston University’s Concrete and Masonry Research to establish the performance characteristics of aircrete masonry units with a density of 350kg/m3.Masonry units were tested in combination with both traditional and thin layer mortars to ascertain the fundamental characteristics for designers. Key physical properties (strength, density, dimension, moisture content, absorption and movement) and thecharacteristic flexural strength of low density Aircrete wallettes are examined and discussed.
Key words
Autoclaved aerated concrete, Low density aircrete, Moisture properties, Masonry construction