对再生混凝土骨料质量进行评估是评价其品质是否满足混凝土结构工程性能要求的关键所在。基于模糊综合评估理论,提出了再生混凝土粗骨料质量等级评估方法。采用表观密度、吸水率、洛杉矶损失值、吸附的水泥砂浆含量、氯化物含量与硫酸盐含量6个指标,将再生混凝土粗骨料划分为3个模糊质量等级,对应于优质、合格与不合格3个状态,给出了不同质量等级再生粗骨料的适用环境作用等级与适用工程。采用基于可信度矩阵与频数统计的CMFS法确定各指标的权重,用最优区间型隶属度函数确定各指标的隶属度以实现等级变化的连续性,采用加权平均模糊算子计算评判矩阵,对评判矩阵作归一化处理后以质量等级评分值作为等级评定的唯一标准。用matlab语言编制了评估程序并用大量的算例验证了评估方法的合理性。
Evaluating for quality of recycled concrete aggregates is crucial for appraising whether their performances accord with actural requirements from concrete structural engineering.A fuzzy synthesis method for evaluating quality class of recycled concrete coarse aggregate was proposed in this paper.Six indices,bulk specific density,water absorption,Los Angeles abrasion loss,attached mortar content,chlorid content and sulfate content were adopted to partition recycled concrete coarse aggregate quality into three fuzzy classes.And the three classes corresponded to excellent,eligible,and unqualified respectively.Farther,their practical environment action grades and corresponding engireenings were suggested.The CMFS method based on credibility matrix and frequency statistic was used to obtain indices weights,and optimum intervel membership function was chosen to decide the memberships of test indices.And synthetic membership score was considered as quality class judgment standard after judgment matrix was calculated by fuzzy weighted average operator.A computing program compiled in Matlab language was taken to calculate large numbers of engineering examples.Results show that the present evaluate method is objective and reliable.