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1.
There is growing concern for corrosion damage in reinforced concrete structures with several decades’ service. Pullout tests
and beam tests were carried out to study the effect of reinforcement corrosion on the bond behavior and bending strength of
reinforced concrete beams. The bond strength of plain bars and concrete initially increases with increasing corrosion, then
declines. The turning point depends on the cracking of the concrete cover. The bond strength of deformed bars and concrete
increases with corrosion up to a certain amount, but with progressive increase in corrosion, the bond strength decreases,
and the cracking of the concrete cover seems to have no effect on the bond strength. On the basis of test data, the bond strength
coefficient recommended here, which, together with the bond strength of uncorroded steel bars and concrete, can be used to
easily calculate the bond strength of corroded steel bars and concrete. The bond strength coefficient proposed in this paper
can be used to study the bond stress-slip relationship of corroded steel bars and concrete. The bending strength of corroded
reinforced concrete beams declines with increasing reinforcement corrosion. Decreased bending strength of corroded RC beam
is due to reduction in steel bar cross section, reduction of yield strength of steel bar, and reduction of bond capacity between
steel bar and concrete.
Project supported by Cao Guanbiao Key Technology Development Founding of Zhejiang University and Construction Ministry of
China. 相似文献
2.
In order to research the bond properties between corroded reinforcement bars and concrete, reinforcement bars with different diameters and different types and concrete with different strength levels were treated specially with all soaking and impressed current method, and the bond properties were measured with the pull-out test. The comparative analysis of the bond properties of corroded reinforcement bars was carried out. The results showed that the types of reinforcement bars and concrete had great influence on the bond strength. The corrosion and volume expansion of reinforcement bars made concrete in tensile condition, which tended to produce cracks in parallel reinforced direction. The typical bond failure of plain reinforcement bars was pull-out, while the typical bond failure of ribbed reinforcement bars was split. The bond strength between corroded reinforcement bars and concrete increased with the increase of concrete strength. The bond strength of plain and ribbed reinforcement bars showed a decreasing trend after the first increase with the increase of the extent of corrosion. Through the test, the coefficients of the bond strength of plain and ribbed reinforcement bars were given, respectively. 相似文献
3.
采用Ansys有限元软件对8根不同锈蚀率的FRP片材加固钢筋混凝土梁的受弯性能进行数值分析,研究纵筋锈蚀率对FRP加固梁的裂纹开展、破坏模式、承载能力以及延性和变形能力的影响.研究结果表明:低钢筋锈蚀率的梁发生受压区混凝土压碎破坏;中等锈蚀率的梁钢筋屈服后,钢筋与混凝土界面发生黏结滑移,最后FRP剥离破坏;高锈蚀率的梁钢筋没有达到屈服强度便发生黏结滑移,最后发生受压区混凝土压碎破坏.钢筋锈蚀越严重,FRP加固钢筋混凝土梁的承载力降低得越多.试件RCB-1(锈蚀率为0)的承载力为115 kN,而试件RCB-7(锈蚀率为20%)的承载力仅为42 kN.与FRP加固未锈蚀的钢筋混凝土梁相比,FRP加固锈蚀钢筋混凝土梁的变形能力较高.试件RCB-1和试件RCB-7的最大跨中挠度分别为20 mm和35 mm,而试件RCB-5(锈蚀率为10%)的最大跨中挠度达到了60 mm. 相似文献
4.
简要说明了研究锈蚀钢筋混凝土构件结构性能的意义，阐述了锈蚀钢筋混凝土构件结构性能的研究状况．主要从混凝土构件中锈蚀钢筋的力学性能、锈蚀钢筋与混凝土间粘结性能和构件的承载能力等方面总结归纳了国内外的研究现状与成果。 相似文献
5.
通过对锈蚀钢筋混凝土构件的低周反复荷载试验，讨论了钢筋锈蚀对混凝土构件的滞回曲线、骨架曲线、刚度、延性、耗能能力、承栽力等不利影响，提出了锈蚀钢筋混凝土构件抗剪承栽力与抗弯承载力计算表达式。 相似文献
6.
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7.
Time-to-cracking of the concrete cover induced by the steel corrosion is one of the critical problems faced by engineers, operators and asset managers in making strategies for the maintenance and repairs of reinforced concrete (RC)structures affected by corrosion. In this paper, a theoretical model for predicting the time-to-cracking is derived by assuming the bond between the steel bar and the concrete as a linear combination of perfectly smooth and bonded. The model takes into account the characteristics of existing exiguous flaws and initial cracks in the concrete before the load acting on RC structures. The validity of the proposed model is preliminarily verified by comparing the obtained results with the available experimental results. A remarkable advantage of the proposed method is its application to the prediction of the service life of RC structures, made of the deformed steel bars as well as the round bars. By determining an experimental constant α, which is related to the interface bond state between the steel bar and the concrete, the service life of RC structures can be predicted using the proposed scheme. Analysis of major factors affecting the time-to-cracking demonstrates that the length of the initial crack affects the service life of RC structures significantly. Moreover, the larger cover thickness and the smaller diameter of the steel bar within a certain range are beneficial to prolonging the time-to-cracking. 相似文献
8.
9.
龙靖华 《安徽广播电视大学学报》1999,(4)
依据有关的试验结果,探讨了钢筋砼结构中砼表面裂缝和钢筋处裂缝宽度及钢筋锈蚀三者之间的关系,并分析了钢筋产生锈蚀的原因,认为以砼表面裂缝宽度作为钢筋锈蚀的度量标准不尽合理,控制钢筋处裂缝宽度防止钢筋的局部锈蚀较为有效 相似文献
10.
本文在利用有限元方法和ANSYS软件对钢筋混凝土植筋建模的基础上,对直径为20mm的Q235钢筋在C20型混凝土中进行数值模拟,得到混凝土的开裂图;又对混凝土植筋在横向力学作用下进行分析得出结论。 相似文献
11.
Seismic behavior of steel reinforced ultra high strength concrete column and reinforced concrete beam connection 总被引：1，自引：1，他引：0
To investigate the seismic behavior of connections composed of steel reinforced ultra high strength concrete （SRUHSC） column and reinforced concrete （RC） beam, six interior strong-column-weak-beam connection specimens were tested subjected to reversal cyclic load. Effects of applied axial load ratio and volumetric stirrup ratio on ductility, energy dissipation capacity, strength degradation and rigidity degradation were discussed. It was found that all connection specimens failed in bending in a ductile manner with a beam plastic hinge. The ductility and energy dissipation capacity increased with the decrease of applied axial load ratio or increase of volumetric stirrup ratio. The displacement ductility coefficient and equivalent damping coefficient lay between those of steel reinforced ordinary concrete connection and those of reinforced concrete connection. The applied axial load ratio and volumetric stirrup ratio had less influence on the strength degradation and more influence on the stiffness degradation. The stiffness degraded sharply with the decrease of volumetric stirrup ratio or increase of applied axial load ratio. The experimental results indicate that SRUHSC column and RC beam connection exhibited better seismic performance and can provide reference for engineering application. 相似文献
12.
钢筋混凝土受弯构件纵向配筋率ρ的取值，现行混凝土设计规范(GB50010—2002)允许的范围是比较大的，然而在实际工程中，钢筋混凝土受弯构件内纵向配筋率ρ的大小对建筑工程质量、耐久性、经济性等方面都有很大影响。该文仅从有屈服点钢筋在钢筋混凝土梁内纵向配筋率入手，通过理论分析、经济比较，研究确定钢筋混凝土受弯构件-梁的合理纵向配筋率。 相似文献
13.
退化钢筋混凝土桥梁概率耐久性评估方法 总被引：1，自引：0，他引：1
提出了考虑时间、空间变异特性的退化钢筋混凝土桥梁耐久性概率评估的随机有限元方法.首先,通过考虑钢筋与混凝土之间时变的粘结滑移关系及腐蚀钢筋的应力应变关系,采用弥散裂纹方法对退化钢筋混凝土桥梁进行有限元分析.然后,提出了退化钢筋混凝土桥梁耐久性概率评估的随机有限元分析方法,基于文献及现场调查的数据,采用蒙特卡罗仿真方法对... 相似文献
14.
基于ANSYS程序的钢筋混凝土梁非线性数值模拟 总被引：2，自引：0，他引：2
采用商用程序ANSYS对不同配筋率的钢筋混凝土梁进行非线性数值分析，以考察不同配筋率对钢筋混凝土梁受弯性能的影响。结合数值模拟分析过程，详细介绍了基于ANSYS程序的钢筋混凝土构件非线性数值分析的关键技术，分析了对不同配筋率的钢筋混凝土粱的刚度变化、破坏特征、截面应力分布、裂缝发展和钢筋、混凝土应力及应变发展过程。 相似文献
15.
冯依锋 《襄樊职业技术学院学报》2013,(3):26-28
详细介绍了钢筋内贴片中心拔出试件的制作方法。中心拔出试验是研究钢筋与混凝土间粘结性能的有效方法,通过钢筋内贴应变片可以测得锚固区内不同位置的钢筋应力,进而揭示钢筋与混凝土的粘结特点。 相似文献
16.
为了研究钢筋增强ECC梁受弯性能,进行了钢筋增强ECC梁和普通钢筋混凝土梁受弯的对比研究.结果表明,相比普通钢筋混凝土梁,钢筋增强ECC梁的受弯承载力和延性分别提高了24.8%和187.76%,并且在梁中用ECC代替混凝土可有效延缓裂缝的发展.此外,采用简化的ECC本构模型对钢筋增强ECC及混凝土梁的受弯性能进行了非线性有限元分析,模拟结果与试验结果吻合较好,在服役期间钢筋增强ECC梁的裂缝可以控制在0.4 mm以下.ECC材料的使用可明显提高梁的抗弯承载力、变形能力、延性等受弯性能. 相似文献
17.
采用ABAQUS有限元软件对各种强度等级下各龄期钢筋混凝土梁的受扭性能进行分析。各龄期混凝土的本构关系采用塑性损伤模型,受拉指标采用断裂能。有限元分析结果表明:各龄期混凝土的抗扭承载力随龄期的增长而增长,开裂前早龄期混凝土梁的抗扭承载力主要由混凝土承担,钢筋的贡献很小;前3d是混凝土扭矩增长最快的主要时间段,开裂扭矩和极限扭矩达到28 d的60%左右。最后,根据有限元参数分析结果,在现行规范的基础上提出了早龄期混凝土梁开裂扭矩和极限扭矩的修正公式。 相似文献
18.
Civil and Hydraulic Engineering Calculation of corrosion rate for reinforced concrete beams based on corrosive crack width简 总被引：1，自引：0，他引：1
This paper deals with a correction method for corrosive crack width caused by non-uniform corrosion. Considering the corrosion cracking characteristics of a reinforced concrete structure, a correction model of corrosive crack width involving the mutual impacts between adjacent measuring points is established. The calculation model for steel bar corrosion rate for single point is obtained through quantitative analysis and accelerated corrosion tests on more than 70 reinforced cubic members. Two methods are suggested by combining two models, the correction and the corrosion calculation ones. Electrolyte accelerated cor- rosion tests on seven beams are carried out to verify these methods. The experimental results show that the ratio between the maximum corrosion rate by the indirect method and the measured average value ranges from 1.4 to 2.4, and the indirect method is shown to be an effective method for calculating the maximum corrosion rate. 相似文献
19.
氯盐外侵和内掺引起的混凝土内钢筋锈蚀特征的比较研究 总被引：1，自引：0，他引：1
氯盐外侵和内掺氯盐是耐久性研究经常采用的两种加速试验方法．通过大量的构件破型发现：氯盐外侵试件中钢筋的锈蚀为靠近混凝土保护层一侧锈蚀比较严重,而背向一侧几乎没有发生;内掺氯盐试件中钢筋的锈蚀特征为钢筋四周均发生锈蚀,靠近混凝土保护层一侧的锈蚀较背向保护层的一侧严重．理论分析和试验研究结果表明混凝土内钢筋锈蚀特征取决于钢筋内外表面的活化状态及钢筋内外表面间宏观腐蚀电流Ig． 相似文献
20.
倒T型钢混凝土组合梁正截面抗弯承载力计算分析 总被引：1，自引：0，他引：1
由一般的非对称性工字型钢混凝土组合梁,采用变形协调模型推导总结不同情况下的型钢混凝土组合梁正截面抗弯承栽力计算公式,进而得到倒T型钢混凝土组合梁的正截面承载力。通过算例,采用推导的理论公式及ANSYS软件对等截面、等含钢量的两类组合梁的极限承栽力进行分析计算,表明倒T型钢混凝土组合梁正截面受力较工字型钢混凝土组合梁好及采用的理论公式是正确可行的。 相似文献