Used concrete recycling - using immersion bath with medium to give hydrophobic action to encapsulate alkali etc. before further use

摘要

To recycle concrete fragments, they are immersed in a watery soln. of a medium to give a hydrophobic quality. The material is treated until pt. of the medium has been absorbed and the components of the concrete which have an adverse effect are encapsulated, esp. the alkalis, and prevented from reacting when producing concrete mixts. from the material. The soln. can also contain an agent to reduce surface tension. ADVANTAGE - The technique renders harmless any components in the broken concrete which would damage concrete mixtures when the used material is recycled. In an example, the concrete fragments are placed in a bath or vessel together with a 5-10% soln. of polydimethylsiloxane, together with a small amt. of an agent to reduce surface tension. The concrete can also be placed in a bath which is already filled with the soln. After the concrete has absorbed sufficient solution to encapsulate any damaging components, it is extracted by a drag chain and left to drip dry in air. The fragments can then be used as an additive for concrete mixts.