灌浆不足对钢筋套筒连接力学性能影响试验

基于已有钢筋套筒灌浆连接的研究成果,通过人为控制灌浆料含量,模拟实际工程中灌浆不足的缺陷,进行套筒连接的静力下单向拉伸试验,研究不同灌浆料含量对静力下钢筋套筒灌浆连接的力学性能、变形性能的影响;进行滞回受力下的高应力反复拉压试验和大变形反复拉压试验,研究不同灌浆料含量对钢筋套筒灌浆连接抗震性能的影响.试验考虑灌浆料含量为影响因素,以钢筋上表面灌浆料的覆没厚度为变量反映水平连接的灌浆料含量,以上侧钢筋在灌浆料中的锚固长度为变量反映竖向连接的灌浆料含量.试验结果表明,钢筋套筒灌浆连接的破坏模式包括钢筋拔出和钢筋拉断,主要取决于钢筋与灌浆料间黏结承载力与钢筋抗拉承载力的相对大小,黏结承载力主要受灌浆料含量的影响.     

套筒约束灌浆料与钢筋黏结强度试验研究

为了对装配式混凝土结构中套筒灌浆连接接头钢筋与灌浆料的黏结性能进行研究,设计了30个灌浆套筒连接节点进行拉拔试验,研究了钢筋锚固长度、灌浆料抗压强度、灌浆料厚度和钢筋直径四个参数对黏结强度的影响.试验结果表明：随着锚固长度增加,钢筋与灌浆料之间的黏结强度降低;随着灌浆料抗压强度增加,钢筋与灌浆料之间的黏结强度增加;随着灌浆料厚度的增加,黏结强度降低,对于12 mm的钢筋,当灌浆料厚度在9 ~ 11 mm之间时,灌浆料厚度对黏结强度影响较小,当灌浆料厚度超过11 mm时,影响显著增加;黏结强度随着钢筋直径的增加而增大.根据试验量测的套筒应变和隔离体受力平衡模型,得到了黏结强度与约束应力、灌浆料抗压强度的关系式,可供工程实际中套筒灌浆连接节点锚固长度取值参考.     

半灌浆套筒连接件抗拉伸性能有限元研究

为了研究半灌浆套筒连接件的抗拉伸性能,采用数字建模方法建立半灌浆套筒有限元模型,研究了钢筋直径、灌浆料强度、钢筋锚固长度、钢筋偏置缺陷等参数的影响规律。研究结果表明,所建立有限元模型能很好地模拟半灌浆套筒连接件的拉伸全过程,且分析结果与试验结果较吻合;随着钢筋直径的增大,半灌浆套筒连接件的极限荷载值和极限位移值均增大;当钢筋锚固缺陷大于2 d时,灌浆料与混凝土间将产生粘结滑移,为防止灌浆料被压碎,建议灌浆料强度应大于100 MPa;钢筋偏置缺陷导致连接件强化阶段荷载值略微降低,沿钢筋受力方向的应力值增大。     

胶合木植筋节点黏结锚固可靠度分析与设计建议

在胶合木植筋节点拉拔试验研究的基础上,建立了胶合木植筋锚固极限状态方程。对胶合木植筋试件的黏结锚固强度、植筋屈服强度、试件的几何尺寸、计算模式的准确性等参数进行回归统计分析。采用一次二阶矩法(中心点法)对胶合木植筋节点黏结锚固性能进行了可靠度分析,得到了针对不同种类植筋的锚固长度的可靠度解,并提出了植筋锚固长度的抗震设计建议,为木结构植筋技术的推广应用提供了参考依据。     

梁铰区搭接节点抗震试验研究

通过对梁铰区采用纵向搭接的筋砼中节点的抗震性能试验研究。探讨了梁铰区搭接连接的可行性。重点分析了不同的搭接型式对梁铰区的弯曲延性、刚度退化，粘结锚固及耗能性能的影响，提出了此类节点最佳锚固型式及锚固长度的设计建设。     

数值模拟分析灌浆缺陷对灌浆套筒连接力学性能的影响

针对实际工程中灌浆料未能填满套筒内腔从而影响钢筋套筒灌浆连接这一现象,通过数值模拟和已知试验对比,采用有限元软件ABAQUS中的内聚力单元模拟钢筋与灌浆料间的粘结滑移,对连接的单调拉伸试验进行了数值模拟计算,模拟结果与现有试验数据比较吻合。同时给出了以钢筋拉断破坏为前提,灌浆料含量最小为优化目标,承载力达到最大的最少灌浆料含量,即竖向连接中上侧钢筋锚固长度取5.5d;横向连接中钢筋上表面覆盖厚度至少为7mm。     

钢筋新型代用材料FRP筋粘结锚固性能试验研究

对混凝土结构中的钢筋新型代用材料ＦＲＰ筋在周围不同环境介质中的粘结锚固性能进行了试验研究。通过对３６个ＦＲＰ筋混凝土和钢筋混凝土所进行的立方体试件中心拔出试验研究,得出了ＦＲＰ筋在混凝土、水泥浆和环氧树脂中的粘结锚固性能。试验结果表明：ＦＲＰ筋在周围不同介质中的粘结锚固性能与钢筋在相应介质中的粘结锚固性能相似;螺旋ＦＲＰ筋的粘结锚固性能要明显高于光面ＦＲＰ筋。     

一种新型化学锚栓的拉拔试验研究

介绍了一种新型化学锚栓,该化学锚栓的锚固剂由无机化学材料组成,具有优越的耐高温性能。通过在C30混凝土中进行M12新型化学锚栓的拉拔试验,对不同锚固长度下的破坏形态进行分析,得出M12新型化学锚栓在C30混凝土中的有效锚固长度,进一步得出M12新型化学锚栓的设计承载力,为新型化学锚栓的工程应用设计提供依据。     

低周反复荷载作用下无机锚固料后锚固受弯构件试验研究

以钢筋锚固深度（15D、200）和后锚固混凝土强度（C20、C30）为参数进行无机材料后锚固混凝土受弯构件低周反复荷载试验,分析研究4组无机锚固料后锚固受弯构件和1组整浇受弯构件在低周反复荷载下的破坏机理、钢筋锚固性能、承载能力、抗震性能．研究结果表明,锚固深度为15D、20D的无机后锚固受弯构件在低周反复荷载下的承载力、钢筋锚固性能及抗震性能均比整浇构件差;无机后锚固受弯构件抗震设计的最小锚固深度建议取为20D,且应考虑附加锚固措施来保证其抗震性能．     

新型预应力混凝土孔道高强灌浆料应用技术研究

对6种不同配合比的灌浆料分别进行了抗折强度、抗压强度、流动度和竖向膨胀率的试验研究,在试验研究的基础上,确定了灌浆料的配合比.配制的预应力混凝土孔道灌浆料具有早强,高强,微膨胀,自流性好等特点,从而增强孔道灌浆的密实度,达到提高预应力混凝土结构的安全度和耐久性的目的.通过实例对预应力混凝土孔道灌浆的应用技术进行了介绍,对工程施工有一定的借鉴意义.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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