| 摘要 |
<p>The invention relates to a process for producing a building material, according to which process a mixture is formed which contains - fly ash, which can, where appropriate, contain other power station ashes and finely divided industrial by products and waste, - a calcium-containing binding agent, such as cement and/or lime, - water, and - a pore-forming agent. The invention is characterised in that 50-99% by weight of ash or ash-containing mixture is mixed with 1-50% by weight of calcium-containing binding agent, after which 20-50% by weight of water and 0.01-1% by weight of pore forming agent, calculated on the dry powder mixture, is added, the mixing is continued in order to make the mass porous with an air content of 20-50% by volume, and the mixture is allowed to harden, after which it is crushed and, where appropriate, fractionated, or else the hardened mass is cut into building blocks. The invention also relates to use of the lightweight crushed ballast which has been produced, for example for manufacturing lime sand brick.</p> |
