| 摘要 |
A synthetic resin bonded concrete comprises as aggregate, coarse grains of a porous mineral material cemented together by a synthetic resin characterized in that the grains of the porous mineral material have a tight smooth surface and the spaces between the grains are filled up by a rigid expanded synthetic resin having closed pores. The grains may have a diameter of at least 5 mm. The porous mineral may be: lightweight concrete, crushed foamed glass, pumice stone, expanded vermiculite and perlite, or expanded clay. The synthetic resin may be: polystyrene, polyurethane, polyvinyl chloride, polyvinyl acetate or a phenolic resin or urea resin. In Examples (1) a mixture of hydroxyl group-containing polyesters, toluene diisocyanate and trichlorofluoromethane was added to expanded clay in a mixer, agitated and cast into a mould, (3) pre-expanded polystyrene obtained by steam treatment of polystyrene grains containing petroleum ester is added to crushed lightweight concrete in a perforated wall mould provided with means for closing it. The pre-expanded polystyrene is caused to expand further under excess pressure and completely fill up the spaces between the lightweight concrete particles. |
