TRC板碳化性能及锈蚀钢筋TRC叠合梁抗弯性能试验研究

发布时间：2018-04-27 00:02

本文选题：织物增强混凝土 + 耐久性　；参考：《江苏科技大学》2017年硕士论文

【摘要】：我国建筑工业化的蓬勃发展,势必带来建筑工程史上革命性的进步,本文研究的织物增强混凝土(TRC)永久性模板是采用不锈钢板网固定纤维织物网,并用高性能细骨料混凝土包裹预制成模板。一方面永久性模板对内部现浇混凝土可以起到保护作用,增强其耐久性。另一方面,永久性模板作为结构体的一部分参与结构受力,从而提高了结构的力学性能,而织物增强混凝土永久性模板的应用更需要应对耐久性的挑战。本文主要研究内容包括力与碳化作用耦合情况下TRC薄板的力学性能试验研究和力与氯盐侵蚀耦合作用下TRC叠合梁的抗弯性能试验研究,研究的主要内容有:(1)对若干TRC薄板和素混凝土薄板构件进行持荷加速碳化,并在正常气候环境下进行破坏加载试验,观测其破坏形态的变化和极限承载能力的退化,分析其破坏机理,并与素混凝土薄板碳化后力学性能的退化进行对比,研究表明:TRC薄板在弯曲性能以及剪切性能上相比普通混凝土薄板具有较大优势,承载力大幅度提升,变形能力得到增强,TRC薄板体现出延性破坏的特点,混凝土先出现裂缝,随后纤维织物网被拉断、剪断。而普通现浇混凝土薄板裂缝的出现预示着加载的基本结束,体现出脆性破坏的特点。随着碳化时间的不断增加,TRC薄板和普通混凝土薄板的承载力均有不同程度的提高。(2)对TRC薄板的开裂荷载和极限抗弯承载力进行了理论推导,得到了开裂荷载和极限抗弯承载力的计算公式,并通过本试验中的数据对计算公式进行了验证,得到了较为理想的计算效果。根据已有的碳化深度预测模型计算了普通混凝土薄板的碳化深度,并与TRC薄板的碳化深度进行对比,分析差异原因,研究表明:TRC薄板的碳化深度小于普通混凝土薄板。(3)制作TRC叠合梁构件,并采用电化学侵蚀方法,加速侵蚀,继而开展抗弯试验,试验制作了2根对比梁和5根TRC叠合梁,分析了氯盐侵蚀作用下因溶液浓度、持荷状态、锈蚀率三因素的不同对试件受弯性能的影响。研究表明:锈蚀状态下TRC叠合梁的力学性能退化情况优于普通梁;U型TRC梁模可以阻碍氯离子的渗入,延缓梁内钢筋锈蚀;在较小的锈蚀率下,TRC叠合梁的屈服荷载和极限荷载略有提升。而随着溶液浓度的提高,钢筋锈蚀率逐渐增大,TRC叠合梁的承载力体现出下降的趋势。(4)对锈蚀状态下TRC叠合梁的抗弯承载力进行理论分析,运用结构力学、材料力学以及数学的知识推导了力与氯盐侵蚀耦合作用下TRC叠合梁的抗弯承载力计算公式,经与实际试验值比较,发现计算值与试验值较为吻合。
[Abstract]:The vigorous development of construction industrialization in China is bound to bring about revolutionary progress in the history of building engineering. The permanent template of fabric reinforced concrete (TRCC) studied in this paper is to use stainless steel plate mesh to fix fiber fabric mesh. High performance fine aggregate concrete is prefabricated into a formwork. On the one hand, the permanent formwork can protect the inner cast-in-place concrete and enhance its durability. On the other hand, as a part of the structure, the permanent formwork takes part in the structural force, which improves the mechanical properties of the structure, while the application of the fabric reinforced concrete permanent template needs to meet the challenge of durability. In this paper, the mechanical properties of TRC thin plates under the coupling of force and carbonation and the bending behavior of TRC composite beams under the coupling of force and chloride corrosion are studied. The main contents of this study are: (1) accelerated carbonization of some TRC thin and plain concrete thin plate members, and the failure loading tests were carried out under normal climatic conditions. The change of failure patterns and the degradation of ultimate bearing capacity were observed. The failure mechanism is analyzed and compared with the degradation of mechanical properties of plain concrete thin plates after carbonization. The results show that the bending and shear properties of TRC / TRC thin plates are superior to those of ordinary concrete thin plates, and the bearing capacity of TRC thin plates is greatly enhanced. The reinforced TRC thin plate shows the characteristics of ductile failure. The concrete first appears cracks and then the fabric mesh is pulled and shearing. The crack of common cast-in-place concrete plate indicates the end of loading and shows the characteristic of brittle failure. With the increasing of carbonization time, the bearing capacity of TRC thin plate and ordinary concrete thin plate have been improved to some extent.) the cracking load and ultimate flexural capacity of TRC thin plate have been theoretically deduced. The calculation formulas of cracking load and ultimate flexural capacity are obtained, and the formula is verified by the data in this experiment, and a more ideal calculation result is obtained. According to the existing prediction model of carbonation depth, the carbonation depth of ordinary concrete thin plate is calculated, and compared with the carbonation depth of TRC thin plate, the reason of the difference is analyzed. The results show that the carbonation depth of the TRC thin plate is less than that of the ordinary concrete thin plate. (3) the TRC composite beam is fabricated, and the electrochemical erosion method is used to accelerate the erosion. Then the bending test is carried out. Two contrast beams and five TRC composite beams are made. The effects of different concentration of solution, loading state and corrosion rate on the bending properties of the specimens were analyzed. The results show that the degradation of mechanical properties of TRC composite beams under rusty condition is better than that of ordinary beams with U-type TRC Liang Mo, which can hinder the penetration of chloride ions and delay the corrosion of steel bars in the beams. The yield load and ultimate load of TRC composite beams are increased slightly under lower corrosion rate. However, with the increase of solution concentration, the corrosion rate of steel bars increases gradually. The bearing capacity of TRC composite beams shows a decreasing trend. The flexural bearing capacity of TRC composite beams under corroded condition is analyzed theoretically, and the structural mechanics is used. The calculation formula of flexural bearing capacity of TRC composite beam under the coupling of force and chloride erosion is derived by the knowledge of material mechanics and mathematics. By comparing with the actual test value, it is found that the calculated value is in good agreement with the experimental value.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU317

【参考文献】