基于改进集对分析的混凝土再生粗骨料质量评价方法

为科学合理地评价再生混凝土粗骨料整体质量等级,提出了基于改进集对分析的再生粗骨料质量等级评价模型。首先参考《混凝土可再生粗骨料标准》(GB/T 25177—2010),选取表观密度等7项因子建立再生粗骨料质量分级的评价指标体系,并确定指标分级标准。然后利用原创联系度可展性对传统集对分析同异反联系度进行修正,构建基于改进集对分析的数学模型,计算单指标优劣等级的同异反联系度的优化值;再结合模糊综合评价理论,以及由熵权法与超标倍数法所确定的指标综合权重,实现对再生粗骨料整体质量的优劣趋同程度进行评价。最后,以某文献中5批再生粗骨料样本为例,运用改进集对分析法进行综合评价。结果表明改进集对分析方法不仅能在初步界定各再生粗骨料样本隶属于2个等级区间范围的基础上,进一步地反映出更偏向某一侧,而且不同等级间的联系度差异效果明显。

A Method of Assessing Recycled Coarse Aggregate for Concrete Based on Improved Set Pair Analysis

A model of assessing the quality grade of recycled coarse aggregate based on improved set pair analysis was proposed. Firstly, the assessment index system composing seven factors inclusive of apparent density was established by referring to the Standard for Renewable Coarse Aggregate of Concrete (GB/T25177-2010) and the criteria for the rating of indexes were determined. Meanwhile, the connection degree identical discrepancy contrary in traditional set pair analysis was modified using developability of connection degree. The mathematical model based on the improved set pair analysis was constructed to calculate the optimal value of identical discrepancy contrary of single index. Moreover, the index weights were determined by using the entropy weight method and the multiple super-scale weighting method; on such basis, the degree of quality convergence of recycled coarse aggregate was assessed based on the fuzzy comprehensive evaluation theory. The proposed method was applied to comprehensively assess the quality grades of five groups of recycled coarse aggregate samples. Results revealed that the proposed modified set pair analysis method could preliminarily define the range of intervals of each grade, and further reflected the inclination towards which grade. Difference in the degree of connection between different grades was also obvious.