再生混凝土粗骨料的质量分级优选评价

为了克服再生骨料比选中主观、随意性等因素带来的误差，并确保对其质量作出科学合理选择，基于组合权重-可拓学理论，建立了混凝土再生粗骨料质量评价模型，根据《混凝土用再生骨料标准》确定评价指标体系和分类等级界限，利用层次分析法和熵权理论确定各指标的主、客观权重；依据可拓学理论求解不同等级下各个指标的样本关联度，然后结合组合权重法计算样本在不同等级下的关联函数值；按照数值越大越优原则进行质量等级评价，最后结合实例检验了评价方法的科学合理性. 研究结果表明:组合权重-可拓学理论综合评价法既能遵循规范单一因素法的评估步骤，还可以详细排序比较各项指标不同等级下的结果；通过实例计算出5组样本的质量等级分别为Ⅱ级、Ⅰ级、Ⅰ级、Ⅱ级、Ⅰ级，这与前人模糊理论评估结果一致；3种权重方法不仅计算出7项再生粗骨料性能指标的具体权重值，而且也能体现出各指标的相对重要性. 通过对再生骨料的质量优选研究，可以为再生混凝土的工程应用提供理论参考. 

Optimization Evaluation of Quality Classification of Concrete with Recycled Coarse Aggregate

In order to overcome the errors caused by the subjective and discretionary factors of the recycled aggregate, select their quality scientifically and reasonably, a quality evaluation model for concrete with recycled coarse aggregate was established based on the combined weight-extension theory. According to the standard of concrete with recycled aggregate, the evaluation index system and limits of classification level were determined, the subjective and objective weights of each indexes were determined by the analytic hierarchy process (AHP) and entropy weight theory. The sample correlation degrees of each indexes under different levels were solved based on the extension theory, and then the correlation function values of the sample under different levels were calculated combined with the combination weight method. The quality grades were evaluated according to the principle that the bigger the number, the better the quality, finally, the scientificity of the evaluation method was tested by examples. The results show that: comprehensive evaluation method based on combined weight-extension theory not only follow the evaluation steps of the single factor method, but also can sort and compare the results under different levels of indicators; the quality grades of the five samples groups are calculated as II, I, I, II, and I, respectively, which are consistent with the evaluation results used by previous fuzzy theory; three weighting methods can not only calculate the specific weight values of seven performance indexes of the recycled coarse aggregate, but also can reflect the relative importance of each indexes. The study on the quality optimization of recycled coarse aggregate can provide a theoretical reference for the engineering application of recycled concrete.