摘要
为了研究工程用钢管微膨胀混凝土的多目标性能需求,采用正交试验的方法研究了膨胀剂、高吸水性树脂SAP、硅灰3种因素对C50钢管微膨胀混凝土工作性、力学性能和耐久性的影响。利用极差分析及方差分析方法分析了各因素对试验指标的主次顺序、显著性影响。基于正交试验综合平衡法分析得出C50钢管微膨胀混凝土在本试验条件下的最优配合比,并通过最优配合比设计参数对比分析,结果表明:该最优配合比的工作性、力学性能和耐久性能相对于基准组均有较大提升,证实了该配合比的混凝土满足所需的多目标综合性能需求。此外,通过压汞试验研究了最优配合比混凝土微观孔结构的变化情况,结果表明:SAP或SAP和硅灰的掺入使得钢管微膨胀混凝土最可几孔径有不同程度的减小且孔隙均向小孔方向发展,使其抗氯离子渗透性能提高;SAP和硅灰的复合掺入使得钢管微膨胀混凝土无害孔占比明显增加,有害孔和多害孔比例减少,孔径分布更合理,使其孔隙结构得到了明显的改善。因此,该研究对于复合型外掺料在钢管密封环境中的应用可提供参考。
In order to study the multi-objective performance requirements of steel tube micro-expansion concrete for engineering,the effects of expansion agent,super absorbent polymer(SAP)and silica fume on the workability,mechanical properties and durability of C50 steel tube micro-expansion concrete are studied by orthogonal test method.The influence of each factor on the primary and secondary order and the significance on the test indicator is analyzed by using range analysis and variance analysis.The optimal ratio of C50 steel tube micro-expansion concrete under our test condition is obtained by comprehensive equilibrium analysis of orthogonal test,and the optimum mix ratio design parameters are used for contrastive analysis.The result shows that the workability,mechanical properties and durability of the optimum mix ratio are improved obviously compared with those of the reference group,which proved that the concrete with this mix ratio meets the requirements of multi-objective comprehensive performance.In addition,the change of microhole structure of the concrete with the optimum mix ratio is studied by mercury injection test.The result shows that(1)the addition of SAP or SAP plus silica fume can reduce the most probable pore of the steel tube micro-expansion concrete in different degrees,and the pores are changed towards the small ones to improve its anti-chlorine permeability;(2)the addition of SAP plus silica fume makes the proportion of harmless pores of steel tube micro-expansion concrete increased obviously,the proportion of harmful pores and multiple harmful pores decreased,and the pore size distribution is more reasonable,which makes the pore structure improved obviously.Therefore,the research can provide a reference for the application of composite admixture in the sealing environment of steel pipe.
作者
黄国栋
张戎令
李华
郭海贞
郝兆峰
HUANG Guo-dong;ZHANG Rong-ling;LI Hua;GUO Hai-zhen;HAO Zhao-feng(Key Laboratory of Road&Bridge and Underground Engineering of Gansu Province,Lanzhou Jiaotong University,Lanzhou Gansu 730070,China;National and Provincial Joint Engineering Laboratory of Road&Bridge Disaster Prevention and Control,Lanzhou Jiaotong University,Lanzhou Gansu 730070,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2020年第6期68-78,96,共12页
Journal of Highway and Transportation Research and Development
基金
长江学者和创新团队发展计划滚动支持项目(IRT_15R29)。
关键词
桥梁工程
钢管微膨胀
正交试验
最优配合比
综合平衡法
多目标性能
bridge engineering
steel tube micro-expansion
orthogonal test
optimal mix ratio
comprehensive equilibrium method
multi-objective performance
