氯盐侵蚀环境下TRC加固小偏心RC柱受压性能的研究

发布时间：2018-06-23 14:45

本文选题：纤维编织网增强混凝土(TRC) + 氯盐干湿循环　；参考：《中国矿业大学》2017年硕士论文

【摘要】：纤维编织网增强混凝土(Textile Reinforced Concrete,简称TRC)是一种由纤维编织网和高性能混凝土结合而成的新型复合材料。TRC加固不仅有FRP加固的一些优点,而且还具有如下优势:其一,采用的高性能混凝土能提高加固层与混凝土基底之间的协调性,同时可抵抗火灾等高温环境的危害;其次,高性能混凝土的密实性、抗离析性、高流动性等,能较好地修复受损结构表面的裂缝,且能给构件中的钢筋再添一层抗腐蚀保护层。本文基于中国矿业大学学科前沿科学研究专项资助项目“海洋干湿环境下持载作用的TRC加固RC偏压柱退化机理研究”,进行了氯盐干湿循环环境下TRC加固钢筋混凝土(RC)小偏心柱受压性能的试验研究,具体研究如下:(1)在研究TRC加固小偏心RC柱的受压性能中,考虑了纤维编织网层数、长细比、配筋率、PVA短切纤维掺量、氯盐干湿循环次数、荷载与氯盐环境耦合作用等因素对加固柱受压性能的影响。结果表明:在氯盐干湿环境中,TRC对小偏心柱的加固效果较好;随着TRC加固层数增加,其加固效果提高,但加固层增加到4层时,加固效果增加变缓;长细比的降低有助于加固柱承载力的改善;配筋率以及PVA短切纤维量一定程度的增加,均有助于提高TRC的加固效果;随着氯盐干湿次数循环次数增多,TRC的加固效果有降低的趋势;荷载与氯盐环境耦合作用对TRC加固柱受压性能的损伤较明显,随着持续荷载的增加,损伤进一步加大。(2)对于TRC加固小偏心锈蚀RC柱的受压性能研究中,考虑了不同纤维编织网层数的影响以及与未锈蚀加固柱的对比情况。结果表明:相比未锈蚀柱,通电锈蚀柱的脆性特征更强,采用TRC加固具有较好的效果,为加固柱提供了良好的抗氯盐侵蚀能力和约束效果;锈蚀柱经加固一层TRC后,承载力有明显的提高,但加固层数继续增加,承载力提高幅度变缓;TRC加固层增加到3层时,锈蚀柱的破坏形态发生了改变,破坏位置从柱中上部移到了柱中部区域。(3)在现有小偏心受压柱正截面承载力计算模型基础上,考虑氯盐干湿循环作用以及TRC约束作用等影响,给出了氯盐干湿循环环境下TRC加固小偏心柱正截面承载力计算模型,理论计算值与试验实际值差别较小。
[Abstract]:Textile reinforced concrete (TRC) is a new type of composite material. TRC, which is composed of fiber woven net and high performance concrete, not only has some advantages of FRP reinforcement, but also has the following advantages: first, The high performance concrete can improve the coordination between the strengthened layer and the concrete base, and can resist the harm of high temperature environment such as fire. Secondly, the density, anti-segregation, high fluidity of the high performance concrete, etc. It can repair the cracks on the surface of the damaged structure and add a layer of corrosion resistant protective layer to the steel bar. In this paper, the degradation mechanism of RC eccentric columns strengthened by TRC in dry and wet environment is studied, based on the special project of frontier scientific research of China University of Mining and Technology. The compressive behavior of small eccentric RC columns strengthened with TRC under dry and wet chloride cycle is studied. The results are as follows: (1) in the study of the compressive performance of small eccentric RC columns strengthened by TRC, the number of fiber woven mesh layers and the ratio of length to slenderness are taken into account in the study of the compressive performance of small eccentric RC columns strengthened by TRC. The influence of the ratio of reinforcement and the content of PVA staple fiber, the number of dry and wet cycles of chlorine salt, the coupling effect of load and chloride environment on the compressive properties of strengthened columns are discussed. The results show that the strengthening effect of TRC on small eccentric columns is better in the dry and wet environment of chlorine salt, and the reinforcement effect increases with the increase of the number of TRC layers, but the increase of the reinforcement effect becomes slower when the strengthening layer is increased to 4 layers. The reduction of slenderness ratio helps to improve the bearing capacity of strengthening columns, and the reinforcement ratio and the amount of PVA short cut fibers increase to a certain extent, which can help to improve the strengthening effect of TRC. With the increase of cycle times of chlorine salt drying and wetting, the strengthening effect of TRC is decreasing, and the damage to the compressive performance of TRC strengthened column is obvious by the coupling action of load and chlorine salt environment, and with the increase of continuous load, (2) in the study of the compressive performance of small eccentric corroded RC columns strengthened by TRC, the effect of different fiber woven mesh layers and the comparison with non-corroded columns are considered. The results show that the brittleness of the corroded column is stronger than that of the non-corroded column, and the TRC reinforcement has a better effect, which provides a good resistance to chlorine salt erosion and restraint effect, and the corroded column is strengthened with a layer of TRC. The bearing capacity is obviously increased, but the number of strengthened layers continues to increase. When the increasing range of TRC reinforcement layer increases to 3 layers, the failure pattern of the corroded column changes. The failure position is moved from the middle and upper part of the column to the middle part of the column. (3) based on the existing calculation model of the normal section bearing capacity of the small eccentrically compressed column, the effects of chlorine salt dry-wet cycle and TRC constraint are considered. The calculation model of normal section bearing capacity of small eccentric column strengthened by TRC under chlorine salt dry-wet cycle environment is presented. The difference between the theoretical calculation value and the experimental value is small.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU375.3

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