| 摘要 |
In masonry bricks, the heat insulation can be increased by reducing the apparent density. However, this is at the expense of the strength of the blank. In order to obtain a reduced apparent density without impairing the strength of the blank, at least 1% by weight of cement, preferably fast-setting cement, is added to the raw mixture of sand, lime and water. In this modified mixture, strength-forming reactions of the cement are allowed to start by leaving the mixture to stand for, for example, 1 hour before compaction. Subsequently, the mass is compacted in a compacting device to give blanks, the pressures applied being low as compared with 150 kp/cm<2>. In this way, lime sand bricks can be obtained which have a proportion of more than 25% of voids and a strength of more than 1 kp/cm<2> and which can be handled without being damaged. |
