Production of porous concrete comprises mixing sand, fine lime, cement, gas former and optionally a sulfate or sulfate carrier and water form a slurry, pouring into molds, and leaving to solidify

摘要

Production of porous concrete comprises mixing sand, fine lime, cement, gas former and optionally a sulfate or sulfate carrier and water form a slurry; pouring into molds; and leaving to solidify. The grain distribution of the sand is adjusted to control the strength, E-modulus, density and/or heat conductivity of the hardened concrete so that a fine SiO 2-rich fraction is present and forms calcium silicate hydrate (CSH) phases, especially tobermorite, with the lime present. Preferred Features: A CaO/SiO 2ratio of 0.6-0.95 is produced. The sand component is ground quartz or ground quartz sand having a grain size of not more than 50 mu m with a distribution maximum of 5-30 mu m.