基于NSGA-Ⅱ与熵权TOPSIS法的混杂纤维再生混凝土配合比多目标优化

Multi-Objective Optimization of Mix Proportion of Hybrid Fiber Recycled Aggregate Concrete Based on NSGA-Ⅱ and Entropy Weight TOPSIS Method

制备以钢纤维(SF)、塑钢纤维(MPPF)为骨料的高性能道面混杂纤维再生混凝土(HFRAC),研究改善再生混凝土(RAC)强度及耐磨性能,采用响应面法(RSM)中Box-Behnken试验设计方法,以SF体积掺量、MPPF体积掺量和砂率为因素,以HFRAC抗折强度、抗压强度和磨损量为评价指标,建立各评价指标的预测模型,分析各因素对评价指标的影响,并构建基于NSGA-Ⅱ耦合熵权TOPSIS法的HFRAC配合比优选模型,确定综合性能最优时的配合比方案。结果表明:在试验范围内各评价指标的响应面模型拟合效果良好,预测精度高;各评价指标不仅受单因素影响,而且受因素间交互作用影响,SF体积掺量与MPPF体积掺量交互作用对抗折强度、抗压强度影响极显著,对磨损量影响显著,MPPF体积掺量与砂率交互作用对抗折强度影响显著;当SF体积掺量为1.39%、MPPF体积掺量为0.97%、砂率为36.10%时,HFRAC综合性能最优。该方法能够实现HFRAC性能的综合改善,可为HFRAC在道路工程中的推广应用提供一定理论依据和技术支撑。

Steel fiber(SF) and macro-polypropylene fiber(MPPF) were used as aggregate to prepare hybrid fiber recycled aggregate concrete(HFRAC) suitable for pavement in order to improve the strength and wear resistance of recycled aggregate concrete(RAC). The Box-Behnken experimental design method was adopted, with the volume content of SF, volume content of MPPF and sand ratio as factors, and the flexural strength, compressive strength and wear amount of HFRAC as evaluation indicators. The prediction model of each evaluation index was established, the influence of each factor on evaluation index was analyzed, and the optimal model of the mix proportion of HFRAC based on NSGA-Ⅱ coupled entropy weight TOPSIS method was constructed to determine the mix proportion scheme when the comprehensive performance was optimal. The results show that the response surface model of each evaluation index has good fitting effect and high prediction accuracy within the test range. Each evaluation index is not only affected by a single factor, but also affected by the interaction between factors. The interaction between the volume content of SF and the volume content of MPPF has a extremely significant effect on flexural strength and compressive strength, and has a significant effect on wear amount. The interaction between the volume content of MPPF and the sand ratio has a significant effect on flexural strength. The optimal mix proportion of HFRAC is obtained. When the volume content of SF is 1.39%, the volume content of MPPF is 0.97%, and the sand ratio is 36.10%, the comprehensive performance of HFRAC is the best. This method can realize the comprehensive improvement of HFRAC performance, and provide a certain theoretical basis and technical support for the popularization and application of HFRAC in road engineering.