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高性能饰面清水混凝土及其施工技术的研究
Research on High Performance Architectural Concrete and Technology for Construction
【作者】 陈晓芳;
【作者基本信息】 华南理工大学 , 交通运输工程, 2011, 硕士
【摘要】 高性能饰面清水混凝土是高性能混凝土与饰面清水混凝土的完美结合,在提高混凝土结构物外观质量的基础上,大大提高工程质量和使用寿命。本文研究高性能饰面清水混凝土在桥梁工程上的应用,对今后大型基础设施(桥梁墩柱、高层建筑)的建设具有一定指导意义。基于桥梁工程高性能饰面清水混凝土施工中所要求的高性能、高饰面效果及施工技术等方面,本文进行了以下研究:(1)通过对高性能饰面清水混凝土聚羧酸高效减水剂的研究,调整聚羧酸成品外加剂的气-固、气-液界面能,改善气泡质量(减少不稳定的大气泡,增加稳定的小气泡),得到最优聚羧酸系减水剂的复配方案为减水剂母液:消泡剂:引气剂=4:0.02:0.03,提高混凝土的工作性能、耐久性能,保证混凝土外观质量,满足高性能饰面清水混凝土的要求。(2)借鉴高密实配合比设计方法优化后的高性能饰面清水混凝土配合比,在胶凝材料用量为440kg/m3,水胶比为0.32,粉煤灰掺量从0~60%时:抗渗等级>P30;28d龄期碳化很微弱;抗冻性能试验质量损失均在1%之内,300次冻融循环后耐久性系数均大于0.8;抗硫酸盐侵蚀能力,经28次循环后,混凝土的质量损失在2%以内,强度损失小于10%;28d电通量小于1000C,混凝土渗透能力低,抗氯离子渗透能力好。用于施工的高性能饰面清水混凝土配合比在满足饰面清水混凝土外观要求的基础上,满足工程施工所需的工作性能、力学性能及耐久性能。(3)系统研究了清水混凝土模板处理工艺,首次提出采用亚克力板、PVC膜两种模板处理工艺。通过对混凝土用各种模板处理工艺的技术及经济性对比分析,优选出集经济性、施工可行性、操作简单、对模板损伤小、消泡作用显著,并能满足清水混凝土外观质量要求的清水混凝土模板施工工艺。(4)将高性能饰面清水混凝土成功应用于实际工程——珠岛一桥,形成系统的高性能饰面清水混凝土施工工艺。
【Abstract】 High-performance architectural concrete is perfect combination of the high-performance concrete and the architectural concrete, based on in improving the appearance quality of the concrete structures, greatly improving engineering quality and service life. This paper researches the application of high-performance architectural concrete in bridge engineering,having guiding significance for large large-scale infrastructure ( bridge pier, high-rise building )in the future. Based on the high-performance architectural concrete construction of the bridge engineering required in the high-performance, decorative effect and the construction technology and so on, this article has conducted the following study:(1) By the study of polycarboxylate superplasticizer used in high-performance architectural concrete, we adjust the gas-solid, gas-liquid interface of polycarboxylate admixture product ,and improve the quality of the bubble (to reduce the instability of large bubbles, increase stability small bubbles). The optimal compounding programs of superplasticizer are polycarboxylate liquor :defoaming agent :air entraining agent=4:0.02:0.03, proposed to improve workability, durability, appearance quality of concrete, which meets the performance requirements of architectural concrete.(2) Through high-density mix design methods to optimize the design of high-performance architectural concrete, when the amount of cementitious material reaches to 440kg/m3 ,the water-cement ratio is 0.32 and the content of fly ash form 0~60%, The results are as follows: anti-penetration level of concrete is higher than P30; 28d age carbonation is very weak; frost resistance test mass loss are within 1%, durability factor is greater than 0.8 after 300 freeze-thaw, mass loss of concrete is less than 2% by 28 cycles while testing resistance to sulfate attack capability; strength loss is less than 10%; 28d flux is less than 1000C. Concrete shows a low permeability and good resistance to chloride ion penetration.Proportion of mixture of high-performance architectural concrete used for the construction not only can meet the appearance requirements of architectural concrete, but also meet the engineering construction required working performance, mechanical properties and durability. (3) This paper studies the treatment process of architectural concrete formwork systematically, first proposed by acrylic plate and PVC film template process. Through technical and economic comparative analysis of a variety of templates treatment process, we optimize the treatment process of fair-faced concrete formwork , which is economic, feasible, simple operation, less damage to formwork, effective in anti-foaming, and the appearance of concrete to meet the quality requirements of architectural concrete.(4)The high-performance architectural concrete successfully used in actual engineering -- Zhudao Bridge, formed the system of high-performance architectural concrete construction technology.
【Key words】 architectural concrete; polycarboxylate superplasticizer; proportion of mixture; durability; template processing; construction technology;