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李维安 《中国安全科学学报》2005,15(5):109-112
提出了一个利用碳纤维混凝土与普通混凝土进行复合,实现结构安全监测的技术方法。根据普通混凝土与碳纤维混凝土之间良好的亲和能力,将碳纤维混凝土浇铸在结构承载的薄弱部分,利用碳纤维混凝土的压敏特性,可以对该部分的服役状态进行监测,获得结构的变形情况;另一方面,利用碳纤维混凝土的基本特性,还可以适当改善结构的承载强度。笔者所提出的复合结构既具有普通混凝土结构的基本特征,又赋予了结构的自我监测功能,比较有效地克服了全碳纤维混凝土结构建造所面临的电阻率波动、骨料石子影响和建设成本等几个方面的技术问题。 相似文献
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In this study, black rice husk ash (BRHA) from a rice mill in Thailand was ground and used as a partial cement replacement. The durability of conventional concretes with high water–binder ratios was investigated including drying shrinkage, autogenous shrinkage, depth of carbonation, and weight loss of concretes exposed to hydrochloric (HCl) and sulfuric (H2SO4) acid attacks. Two different replacement percentages of cement by BRHA, 20% and 40%, and three different water–binder ratios (0.6, 0.7 and 0.8) were used. The ratios of paste volume to void content of the compacted aggregate (γ) were 1.2, 1.4, and 1.6. As a result, when increasing the percentage replacement of BRHA, the drying shrinkage and depth of carbonation reaction of concretes increased. However, the BRHA provides a positive effect on the autogenous shrinkage and weight loss of concretes exposed to hydrochloric and sulfuric acid attacks. In addition, the resistance to acid attack was directly varied with the (SiO2 + Al2O3 + Fe2O3)/CaO ratio. Results show that ground BRHA can be applied as a pozzolanic material and also improve the durability of concrete. 相似文献
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从理论和实践两方面提出用后浇带的方法,可以达到控制混凝土水池裂缝,取消或扩大永久伸缩缝间距的目的,同时介绍了后浇带的设计原则和施工方法,以及注意事项 相似文献
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Yoshiro Ono Hidehito Uemura Yoshinori Kanjo Osami Kawara Toshiki Ayano 《Journal of Material Cycles and Waste Management》2000,2(1):38-42
Construction waste such as road pavement and concrete is estimated to constitute about 50% of the total industrial waste in
Japan, and the recycling of such material has recently become a prominent topic among construction engineers. It has also
been suggested that various types of industrial waste be utilized as components of construction materials. This paper investigates
the environmental safety of certain materials in terms of the elutions and genotoxicities of these substances. The substances
extracted from some materials, such as emulsifier, ash, and sediment, were found to have genotoxic characteristics. The dose-related
responses of the various materials and their genotoxic strengths are shown.
Received: June 16, 1998 / Accepted: September 7, 1999 相似文献
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Due to ever increasing quantities of waste materials and industrial by-products, solid waste management is the prime concern in the world. Scarcity of land-filling space and because of its ever increasing cost, recycling and utilization of industrial by-products and waste materials has become an attractive proposition to disposal. There are several types of industrial by-products and waste materials. The utilization of such materials in concrete not only makes it economical, but also helps in reducing disposal concerns. One such industrial by-product is waste foundry sand (SFS). Waste foundry sand is a by-product of ferrous and nonferrous metal casting industries. Foundries successfully recycle and reuse the sand many times in a foundry. When the sand can no longer be reused in the foundry, it is removed from the foundry and is termed as waste foundry sand.Published literature has shown that WFS could be used in manufacturing Controlled Low-Strength Materials (CLSM) and concrete. This paper presents an overview of some of the research published on the use of WFS in concrete. Effect of WFS on concrete properties such as compressive strength, splitting tensile strength, modulus of elasticity, freezing-thawing resistance, and shrinkage are presented. 相似文献
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较大含湿量是试验用混凝土结构的一个主要特点。根据火灾试验的特点,在大量调研的基础上,结合作者在试验中的经验教训,对含湿量对混凝土结构抗火性能试验的影响做了阐述,这些影响有关于材料性能的,有关于温度场分布的,有关于混凝土爆裂的,有关于结构变形的,有关于结构耐火极限的。重点分析了含湿量对结构变形的影响,讨论了一些有价值的建议和研究方向,对今后混凝土结构抗火性能试验有较大的借鉴意义。 相似文献
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复杂地基重力坝深层抗滑稳定非线性有限元分析 总被引:7,自引:1,他引:7
重力坝的深层抗滑稳定是保证大坝安全的一个重要条件。针对《混凝土重力坝设计规范》(DL5 10 8—1999)中关于复杂地基重力坝的稳定性需进行有限元分析的新规定,笔者结合某重力坝稳定问题实例,用非线性有限元方法进行了分析计算,并与刚体极限平衡法及结构可靠度分析方法的成果进行了对比。对有限元法的适用性,岩体侧面阻滑力的影响及抗滑稳定安全度的表达方法等问题进行了探讨 相似文献
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The paper provides a model for the cutting of reinforced concrete members with stream-line cutting tools. The model is an extended version of the energy model originally developed by Momber and Kovacevic (1995) for hydro-abrasive machining. The model allows the stepwise calculation of the energy absorbed during the cutting of the two parts of the compound - steel bar and matrix material. Hydro-abrasive cutting tests on different cementitious composites are performed in order to verify the numerical results. It is shown that the cutting process can be subdivided into four cutting stages whose locations depended on the energy locally available at the erosion site. 相似文献