超早强纤维混凝土加固柱抗震与耐火性能研究

发布时间：2018-08-09 14:26

【摘要】：超早强纤维混凝土材料以具有高耗能、耐火、高粘结应力、微膨胀等良好性能近年来在加固钢筋混凝土结构中深受重视,在施工过程中具有快捷方便,影响较小的优点,在加固中得到广泛应用,由于超早强纤维混凝土材料起步较晚,许多方面还不成熟需进一步研究。多重灾害容易对钢筋混凝土柱的抗剪性能产生明显损伤,甚至使柱产生剪切破坏,钢筋混凝土结构在遭受多重灾害损伤后,材料的力学性能将产生大幅度下降,导致整体结构安全性能降低。由于目前国内对多重灾害后钢筋混凝土柱残余抗剪承载力性能的研究相对较少,而对于地震区多重灾害后钢筋混凝土结构的损伤评定和加固修复建议无疑是最重要的。本文以钢筋混凝土柱为研究对象,从材料试验、结构试验、损伤分析三个方面对此结构的抗剪及其抗震性能展开系统研究。本文主要工作如下：(1)进行了4组火灾高温后不同配合比的超早强纤维混凝土材料立方体试件的试验,考察了碳纤维掺量、粗骨料、聚丙烯纤维掺量、铝酸盐水泥与普通硅酸盐水泥质量比等因素在不同温度下试件受压承载力的影响情况。试验结果表明：1)高温后试件的受压承载力随温度升高逐渐降低,当试件在200℃、400℃、600℃、800℃后峰值荷载相比常温下分别下降了9.8%、28.2%、42.2%、55.6%；2)颜色深度随温度升高逐渐增大,随温度的升高,试件的颜色由灰色,变为暗红,最后变为灰白；3)裂缝宽度与深度随温度的升高不断增大。(2)进行了6根超早强纤维混凝土材料柱和2根超早强纤维混凝土材料加固C30混凝土柱的抗震试验,考察了轴压比、粗骨料、碳纤维掺量等因素对混凝土柱的抗剪承载力、滞回耗能能力、延性的影响情况。试验结果表明：1)轴压比是影响钢筋混凝土柱抗剪承载能力的重要指标；2)纤维掺量在一定范围内对提高抗剪承载能力起促进作用。(3)进行了4根超早强纤维混凝土材料柱、5根超早强纤维混凝土材料加固C30混凝土柱和1根C30混凝土柱在多重灾害后的抗震性能试验,考察了不同温度、不同时间等因素对混凝土柱的抗剪承载力、滞回耗能能力、延性的影响情况。试验结果表明：1)裂缝宽度与数量随温度的升高逐渐增大；2)试件表面颜色深度随升温时间增加逐渐减小。
[Abstract]:Ultra-early strength fiber reinforced concrete materials with good properties such as high energy consumption, fire resistance, high bond stress and micro-expansion have been attached great importance in the reinforcement of reinforced concrete structures in recent years, and have the advantages of quick, convenient and less influence in the construction process. It has been widely used in reinforcement. Due to the late start of ultra-early strength fiber reinforced concrete materials, many aspects need to be further studied. Multiple disasters can easily damage the shear behavior of reinforced concrete columns, and even cause shear damage to the columns. The mechanical properties of reinforced concrete structures will be greatly reduced after they are damaged by multiple disasters. The safety performance of the whole structure is reduced. At present, there are few researches on the residual shear bearing capacity of reinforced concrete columns after multiple disasters, but it is undoubtedly the most important to evaluate the damage of reinforced concrete structures after multiple disasters and to strengthen and repair them. In this paper, the shear resistance and seismic behavior of reinforced concrete columns are systematically studied from three aspects: material test, structural test and damage analysis. The main work of this paper is as follows: (1) four groups of cubes of ultra-early strength fiber concrete material with different mix ratio after fire high temperature were tested, and the content of carbon fiber, coarse aggregate and polypropylene fiber were investigated. The influence of the mass ratio of aluminate cement to ordinary Portland cement on the compressive capacity of specimens at different temperatures. The results show that the compressive capacity of the specimen decreases gradually with the increase of temperature after high temperature, and the peak load of the specimen decreases by 9.828.2 / 42.2and 55.6% with the increase of temperature when the peak load of the specimen at 200 鈩，

本文编号：2174368