<p>A lightweight gas concrete containing siliceous concrete and limy material as the principal material and produced by steam curing under high-temperature and high-pressure conditions. The concrete further contains 0.1-1.0 wt.% of silicone oil and has a bulk specific gravity of 0.55 to 1.0, a porosity of 2.5 or above, and a water absorption percentage of 10-25 vol.%.</p>
