隧道结构防水抗渗混凝土优化配合比的正交试验分析  

Orthogonal Test Analysis of Optimal Mix Ratio of Waterproof and Impermeable Concrete for Tunnel Structure

作　　者：黄勇强 HUANG Yongqiang(China Railway 18^(th)Bureau Group Municipal Engineering Co.Ltd.,Tianjin 300222,China)

机构地区：[1]中铁十八局集团市政工程有限公司,天津300222

出　　处：《铁道建筑技术》2022年第11期110-115,共6页Railway Construction Technology

基　　金：中国铁建股份有限公司科技研发计划项目(2018-C02)。

摘　　要：针对混凝土渗透性能、防水性能较差等问题,通过室内试验研究混凝土最佳配合比,以此得到具有较好防水抗渗能力,且基材性能良好的混凝土材料。采用正交试验方法,通过力学试验、膨胀率测试、核磁共振试验和渗透试验确定粉煤灰、矿粉、纤维素纤维等材料最佳掺和比。研究表明:粉煤灰、矿粉、添加剂和纤维素纤维优化掺量分别在10%~20%、15%~20%、4%~6%和0.9~1.5 kg/m范围内;添加剂(膨胀剂)使混凝土密实度得到充分提升,有效预防混凝土出现收缩裂缝;粉煤灰、矿粉的加入,可以改变混凝土孔隙结构,提升其物理性质;而纤维素纤维使混凝土内部发生水化反应,提升混凝土抗渗性能;由此得出最优配比混凝土,其力学、防水抗渗性能得到全面提升。To address the problems of poor permeability and waterproof performance of concrete,the best concrete mix ratio was studied through indoor tests to obtain a concrete material with good waterproof and impermeability resistance and good performance of the base material.The best mixing ratio of fly ash,mineral powder and cellulose fiber was determined by mechanical test,swelling rate test,nuclear magnetic resonance test and permeability test using orthogonal test method.The study shows that the optimized blending ratios of fly ash,mineral powder,additives and cellulose fiber are in the range of 10%~20%,15%~20%,4%~6%and 0.9 kg/m to 1.5 kg/m,respectively.The additive(expander)makes the concrete denseness fully enhanced and effectively prevents shrinkage cracks in concrete.The addition of fly ash and mineral powder can change the pore structure of concrete and enhance its physical properties,while cellulose fibers make the internal hydration reaction of concrete and enhance the impermeability of concrete.The resulting optimally proportioned concrete has fully enhanced its mechanical,waterproof and impermeable properties.

关 键 词：混凝土 正交试验 力学性能 膨胀率 防水抗渗 

分 类 号：TU528.32[建筑科学—建筑技术科学] U454[建筑科学—桥梁与隧道工程]