| 摘要 |
<p>22 In a method of casting different types of concrete products without the need of using a curing chamber or an autoclave the concrete, subsequent to mixing, is casted and externally and/or internally subjected to a vacuum treatment to have it de-watered and compacted. Then carbon-dioxide gas is supplied to the mass whilst maintaing a sub- or under-pressure in a manner such that the gas - as a result of the sub-pressure - diffuses into the capillaries formed in the concrete mass, to quickly harden the mass. In one embodiment - in which the mass is de-watered and compacted by means of a mat or plate placed thereupon and exposed to a sub-pressure via a pipe or a line - the carbondioxide gas is supplied via said mat or plate whilst using the under-pressure prevailing in the mass. In another embodiment the sub-pressure is applied from one or more sides of the mould to the interior of the element being cast, either by means of special inserts, by holes or cavities inside the element or via a porous material layer in the inner portion thereof. Then the carbondioxide gas is supplied correspondingly. These two main embodiments may in certain cases be combined in different ways. Further the concrete may at the same time or subsequently be subjected to another type of treatment such as impregnation by a suitable solution.</p> |
