| With the renewal, transformation and construction of public and civil building, municipal facilities in urban areas, in the building process, a large number of old buildings were torn down, thus a lot of construction waste was produced which occupied 30~40% of the total waste. Now we always use two methods to dispose construction waste: one is burying them in the outskirt, the other is dumping them in the river. But the two also bring a certain negative impact, the former will bring occupation and plunder of agricultural land while the latter will affect flood season. In addition, we must pay transportation costs for refuse removal and pay disposal costs for using of farmland. If we replace natural and with recycled aggregate made by waste concrete to make concrete, then the waste concrete can be regarded as raw material to be used in the new building, then the aim of resource reuse is achieved and it also can resolve the issue of handling waste concrete fundamentally. Therefore, many scholars began to study waste concrete, but a lot of research was about the basic mechanical nature of it, few studied its frost resistance. Even someone studied the frost resistance, only freezing-thawing cycles was discussed, early frozen of newly shaped concrete and one-time frozen of hardened recycled concrete was not explored.On the base of the experiment done by my Fellow apprentices Zhang-Xuebing, this paper studied the frost resistance of recycled concrete through experiment. Including : the frost temperature of recycled concrete; the effect of procuring days on one-time freezing; the frost rule of recycled concrete with different strength grades; the effect of frost temperature on recycled concrete; the effect of freezing days on the strength of recycled concrete; Whether the recycled concrete does exist critical frozen strength ; the most feasible content of antifreeze in recycled concrete; the strength development of recycled concrete with antifreeze curing in standard condition; the strength development of recycled concrete mixed antifreeze maintaining under negative temperature; the strength of recycled concrete with antifreeze curing 28 days in standard condition after maintained under negative temperature; recycled concrete anti- thawing-freezing cycles ability; anti- frozen performance comparison between recycled concrete with antifreeze and recycled concrete without antifreeze; then, made comparison between ordinary concrete and... |
