再生粗骨料的随机特性及分级方法研究

通过96个不同来源废旧混凝土再生粗骨料样本的试验,研究了再生粗骨料吸水率、堆积密度、饱和面干表观密度和压碎指标的概率分布特征。试验结果表明,四个指标均服从正态分布。根据相对方差和极差分析结果,确定了吸水率和压碎指标作为再生粗骨料品质分级的控制指标。然后对不同来源再生粗骨料混凝土进行抗压强度试验,得到了再生粗骨料吸水率和压碎指标的分级范围,从而提出了再生粗骨料品质的分级方法。最后利用其他研究者的试验数据,验证了该方法对再生粗骨料分级的合理性。

STUDY ON STOCHASTIC CHARACTERISTICS AND CLASSIFICATION CRITERIA OF RECYCLED COARSE AGGREGATE

The stochastic characteristics were investigated for the water absorption, packing density, apparent density and crushing index of 96 recycled coarse aggregate experiment samples from different demolition waste concretes. Experimental results show that these four indexes have a normal distribution. The water absorption and crushing index can be used as the index in the classification of recycled coarse aggregate based on a relative variance and a range analysis. Then, the compressive strength of concrete with recycled coarse aggregate from different demolition waste concretes was classified and the ranges of water absorption and crushing for the classification of recycled coarse aggregates were decided according to the strength grades of recycled coarse aggregate concrete, and the classification criteria was presented. At last, its validity was verified by the test data obtained by other researchers.