为了解兰州地区商品混凝土用骨料的各项性能指标，对从兰州12家商品混凝土拌合站抽取的细骨料进行了颗粒级配、细度模数、含泥量、泥块含量和快速碱—硅酸反应等试验，对粗骨料进行了含泥量、泥块含量、针片状颗粒含量、快速碱—硅酸反应等试验。结果表明：兰州地区商品混凝土所用细骨料中粗颗粒所占比例偏大，颗粒级配不符合规范要求，含泥量较高，有明显的潜在碱—硅酸反应危害；而粗骨料泥块含量较高，发生碱—硅酸反应危害的概率较细骨料低。分析了问题产生的原因，并给出了优化建议。%T o study the performance parameters of commercial concrete aggregate in Lanzhou province,the paper takes the fine and coarse aggregates of 12 commercial concrete mixing centers in Lanzhou. Fine aggregates samples are put under tests for grain gradation,fineness modulus,silt content,silt-lump content and rapid AAR performance, while coarse aggregates samples are tested for silt content,silt lump content,elongated grain content and rapid AAR performance. T he results indicate that fine aggregate tend to be high in coarse particle ratio,concrete content and possibility of AAR risk,which does not comply with the regulation concerned. At the same time,the coarse aggregate displays a high silt-lump ratio,yet its potential for AAR risk is relatively low compared with fine aggregate. On this basis,the paper looks into the cause behind and offers countermeasures accordingly.
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