共查询到19条相似文献，搜索用时 247 毫秒
1.
为探究ECC材料受弯性能,对受弯钢筋增强ECC双筋梁正截面进行了理论和试验研究.首先基于平截面假定和材料本构模型,得到各阶段承载力计算方法.然后,通过试验结果与理论结果对比,验证所提出的梁承载力计算方法正确性.最后,基于所提出的理论公式,对ECC材料的抗压强度和抗压应变、抗拉强度和配筋率进行分析,探究其对钢筋增强ECC双筋梁正截面受弯性能的影响.理论分析结果与试验结果吻合良好,说明理论分析模型能够用于预测钢筋增强ECC梁的弯矩-曲率关系.参数分析结果表明:提高ECC抗压强度将大幅改进梁受弯性能;提高ECC极限受压应变可大幅提高梁极限曲率和延性,但对受弯承载力影甚微;ECC抗拉强度对梁受弯性能影响微弱;配筋率的增大可大幅提高梁受弯承载力和刚度,但会降低梁的延性.所提出的理论计算模型和参数分析结果对于钢筋增强ECC梁受弯性能的设计研究具有指导意义. 相似文献
2.
《石家庄铁路职业技术学院学报》2017,(4)
本文以重庆西站东站房预应力混凝土结构为工程背景,对预应力结构的长期监测方法进行了研究。采用的方法为,通过锚索计监测预应力钢筋的内力变化,利用钢筋计和混凝土表面应变计测量普通钢筋应力和混凝土的表面应变,通过静力水准仪监测预应力混凝土梁的竖向变形——挠度。通过分析现场量测结果发现,本文方法可实时监测预应力混凝土梁的安全状态,了解梁的健康状况。 相似文献
3.
对无粘结预应力钢筋性能进行了分析．本文通过用实验数据验算理论计算结果的途径,建立了计算刚度综合系数的公式,并对其中的一些系数等加以比较,以探求一个尽可能符合实际的通用的短期刚度计算方法。 相似文献
4.
通过制作1根普通混凝土深梁和8根沙漠砂混凝土深梁来研究沙漠砂掺量、剪跨比、箍筋配筋率和混凝土强度等级对沙漠砂混凝土深梁挠度和短期刚度的影响,并采用中国混凝土结构设计规范和有效惯性矩法对深梁试件短期刚度进行理论值计算.结果表明:沙漠砂混凝土深梁试件跨中挠度随剪跨比和箍筋配筋率的增大而增大,随混凝土强度等级的增大而减小,随... 相似文献
5.
云南某预应力混凝土简支T梁桥主梁竖向开裂,对该桥采用张拉体外预应力钢绞线进行加固.为验证加固效果,对6#跨在加固前、后进行静载试验,试验结果表明:加固前,L/2截面梁底应力及挠度校验系数均大于1,判断该桥承载能力不满足公路Ⅱ级(JTG D60-2015)荷载要求.加固后,L/2截面梁底应力及挠度校验系数均小于1,T梁抗裂性及刚度显著提升,在试验荷载作用下,体外钢绞线与T梁能够共同协调受力,桥梁承载能力满足设计荷载要求.荷载试验结果显示该桥加固效果良好. 相似文献
6.
《实验室研究与探索》2013,(12):48-53
借助有限元软件ANSYS,对钢筋混凝土简支梁在单调竖向荷载作用下进行受力全过程非线性计算,对超筋梁和适筋梁,提出分别以混凝土的极限压应变达到εcu和受拉钢筋的极限拉应变达到0.01作为达到极限承载力的判别标准;分析钢筋混凝土梁完整的破坏过程、力学特征,研究受压钢筋、配筋率和材料强度对梁极限承载力的影响,数值分析得出应用高强、高性能钢筋能提高资源利用效率,即截面承载力显著提高的同时,钢筋混凝土构件的延性并未降低等结论。 相似文献
7.
冉康 《淮南职业技术学院学报》2004,4(1):53-55
通过11根无粘结部分预应力高强混凝土梁，研究了影响裂缝闭合的主要因素；预应力筋配筋率、非预应力筋配筋率、跨高比、荷载作用方式，用无粘结配筋指标βpe和换算配筋率αpp这两个参数来反映对裂缝闭合弯矩的影响，应用名义拉应力建立了闭合弯矩计算公式；计算结果与试验结果吻合较好。 相似文献
8.
通过分析高强预应力混凝土板桩截面的抗弯系数的3种不同计算方法,探讨了板桩截面形状、尺寸与抗弯系数之间的关系。与现有的其它类似板桩产品相比,新研发的高强预应力槽形板桩有效提升了截面抗弯系数,提高了混凝土板桩的抗弯弯矩和抗裂弯矩。研究成果将对高性能预应力混凝土板桩优化设计和施工具有指导意义。 相似文献
9.
为研究预应力混凝土连续箱梁桥的承载能力及实际工作状况,通过实际桥梁的静载试验,测得桥梁在各个工况下控制截面的应变、挠度随荷载增加能保持良好的线性关系,并判断实测残余变形与实测总变形比值小于0.2,同时采用桥梁专用有限元计算分析软件MIDAS/Civil建立试验跨模型,与静载试验实测数据进行对比分析,得到桥梁的应变校验系数和挠度校验系数,综合判断桥梁的承载能力能满足要求。 相似文献
10.
后张法预应力混凝土构件具有抗裂度强、刚度大、混凝土梁剪力小、自重轻等优点,但是比较复杂、质量要求高。因而,本文从模板安装、绑扎钢筋、钢绞线波纹管施工、浇筑混凝土以及压浆等方面对后张法预应力混凝土现浇箱梁施工质量进行探讨。 相似文献
11.
Through the experiments of 7 T-section composite beams, steel fiber reinforced self-stressing concrete （SFRSC） as the composite beam in the composite layer was studied under the hogging bending. The tests simulated composite layer tensile strain under the hogging bending of inverted loading composite beams, giving the relationship under the different fatigue stress ratios between fatigue cycles and steel bar’s stress range, crack width, stiffness loss and damage, etc., in composite layer. This article established fatigue life equation, and analyzed SFRSC reinforced mechanism to crack width and stiffness loss. The results show that SFRSC as the composite beam concrete has excellent properties of crack resistance and tensile, can reinforce the fatigue crack width and stiffness loss of composite beams, and improve the durability and in normal use of composite beams in the hogging bending zone. 相似文献
12.
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
13.
EFFECT OF CORROSION ON BOND BEHAVIOR AND BENDING STRENGTH OF REINFORCED CONCRETE BEAMS 总被引：1，自引：0，他引：1
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅｉｓｇｒｏｗｉｎｇｃｏｎｃｅｒｎｆｏｒｃｏｒｒｏｓｉｏｎｄａｍ ａｇｅｉｎｒｅｉｎｆｏｒｃｅｄｃｏｎｃｒｅｔｅ (ＲＣ)ｓｔｒｕｃｔｕｒｅｓｗｉｔｈｓｅｖｅｒａｌｄｅｃａｄｅｓ’ｓｅｒｖｉｃｅ.Ｔｈｅｒｅｉｎｆｏｒｃｅｍｅｎｔｃｏｒ ｒｏｓｉｏｎｏｆＲＣｃｏｎｓｔｒｕｃｔｉｏｎｓｐｒｏｂａｂｌｙｉｓｔｈｅｍｏｓｔｓｉｇｎｉｆｉｃａｎｔｐｒｏｂｌｅｍａｎｄｏｕｔｗｅｉｇｈｓｏｔｈｅｒｆｏｒｍｓｏｆｄｅｔｅｒｉｏｒａｔｉｏｎ .ＳｔｕｄｉｅｓｂｙＰｅａｔｔｉｅｅｔａｌ.( 1 9… 相似文献
14.
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
15.
Anti-seismic behavior of HRB400 reinforced steel bars 总被引：1，自引：0，他引：1
秦斌 《重庆大学学报(英文版)》2005,4(1):23-27
1 Introduction Steel bar is one of the most important constructional materials ensuring the safety of buildings, and sufficient anti-seismic strength is required when it is applied to buildings in the region where an earthquake might occur. HRB335 steel bars are being used in China while 400 MPa steel bars are wildly used in Europe [1]. To ensure the security of buildings, 400 MPa steel bars have been developed in China. Before these steel bars being wildly used, a full-scale survey of the… 相似文献
16.
A three-dimensional finite element model was established for a large span concrete filled steel tubular (CFST) arch bridge which is currently under construction. The arch rib, the spandrel columns, the prestressed concrete box-beam, the cast-in-situ concrete plate of bridge deck, the steel box-beam and the crossbeams connecting the two pieces of arch ribs, were modeled by three-dimensional Timoshenko beam elements (3DTBE). The suspenders were modeled by three-dimensional cable elements (3DCE). Both geometric nonlinearity and prestress effect could be included in each kind of element. At the same time a second finite element model with the same geometric and material properties excepted for the sectional dimension of arch rib was set up. Static dynamic analyses were performed to determine the corresponding characteristics of the structure. The results showed that the arch rib's axial rigidity could be determined by static analysis. The stability and vibration of this system could be separated into in-plane modes, out-of-plane modes and coupled modes. The in-plane stability and dynamic characteristics are determined by the arch rib's vertical stiffness and that of out-of-plane is determined by the crossbeams' stiffness and arch rib's lateral stiffness mainly. The in-plane stiffness is much greater than that of out-of-plane for this kind of bridge . The effect of geometric nonlinearity and prestress effect on bridge behavior is insignificant. 相似文献
17.
大跨预应力混凝土连续刚构桥墩梁结合部位受力复杂,且布置数量较多的预应力钢束,是刚构桥中的关键部位。结合昆明市城市三环路东段工程预应力混凝土连续刚构桥的设计方案,利用有限元分析软件ANSYS对墩梁固接区进行精细有限元局部分析,得到施工阶段及运营阶段墩梁固结区的应力分布。结果表明该结构预应力配束合理,施工阶段及运营阶段应力均满足设计规范要求。 相似文献
18.
We proposed a bilinearity constitutive curve model of fiber reinforced polymer （FRP） confined concrete which includes a parabola in the first stage and a straight line in the second stage. The FRP-confined concrete has powerful confinement status and weak confinement status leading to different equations of parabola. We analyzed the impacts of factors such as confinement ratio and restrain stiffness on confined concrete compressive strength, ultimate strain and other control parameters through finite element analysis. The results show that the confinement ratio determines the confinement status, and the increase of the confinement ratio has a limited capacity to increase the compressive strength, The deformation of confined concrete is influenced by restrain stiffness. The stronger the restrain stiffness is, the less the lateral deformation is and the greater ultimate axial strain will be. The consideration of equivalent section coefficient kse is needed in the non-circular section confined concrete. We analyzed the results and proposed boundary values of strong and weak confinement styles, a peak/inflection point stress and strain model, and a compressive strength and ultimate strain model. 相似文献
19.
建立了T形配钢型钢混凝土偏压构件力学性能分析的有限元模型,计算结果得到以往实验结果的验证。在此基础上,分析了不同阶段材料应力状态和各参数对偏压构件力学性能的影响。结果表明:T形配钢型钢混凝土构件在不同加载角下的性能有所不同,加载角为180°时极限承载力大于其他角度情况;混凝土抗压强度、型钢含钢率、配筋率、荷载偏心率、长细比对构件荷载-变形曲线的影响较大,随着混凝土强度、型钢含钢率、配筋率的增加,极限承载力和刚度增加;随着荷载偏心率的增加,极限承载力和刚度下降;随着构件长细比的增加,构件承载力总体呈现线性下降趋势,刚度下降明显。 相似文献