Improvements in the production of concrete

摘要

663,568. Porous concrete. BESSEY, G. E. Dec. 5, 1949 [Dec. 3, 1948], No. 31367/48. Classes 22 and 70 The aggregate of a light-weight concrete is partly or wholly composed of pulverized fuel ash. The aggregate need not be entirely finely divided, and the pulverized fuel ash need not comprise the whole of that part which is finely divided, in which latter case sand is used. The set concrete is hardened by steam at high pressure. To render the concrete porous a framing agent is used.