不同锚具锚固高强钢绞线性能的分析

随着钢绞线与钢绞线网加固在实际工程中的应用,为了锚固住钢绞线,该工程领域出现了多种类型的锚固构件。本文通过试验分析不同锚固构件对钢绞线锚固性能的影响,筛选出较优的锚固构件,为钢绞线及钢绞线网加固的进一步推广和研究提供参考依据。试验数据的分析结果表明,八字型铝扣的力—力矩曲线最为稳定,U型玛钢卡扣表现最差;再依据锚具性能的分析结果,选用八字型铝扣制作试件进行模拟施工张拉实验,通过分析力与伸长值、力与力矩之间的变化关系,推导出张拉钢绞线的力—伸长值、力—力矩计算公式。     

砌块专用砂浆与钢筋黏结性能试验研究

通过12组试件的拉拔试验,建立黏结应力与滑移(τ S)关系曲线,确定了锚固钢筋受力破坏的各个阶段(微滑移、内裂滑移、劈裂、下降和残余五个阶段),综合分析了砂浆强度、锚固长度和钢筋直径对黏结锚固性能的影响·试验结果表明:在给定的l/d的条件下,黏结强度随砂浆强度增加而提高,随相对锚固长度和钢筋直径的增大而降低·最后,考虑砂浆的劈拉强度和相对锚长,利用最小二乘法,通过统计回归提出了黏结特征强度的统计公式·     

CFRP筋粘结式楔型锚具锚固性能分析

为研究CFRP筋粘结式楔型锚具锚固性能及其影响因素,对12套CFRP筋粘结式楔型锚具进行静载试验,以锚具内倾角和锚固长度为变化参数,获取锚具试件荷载—滑移全过程曲线,推出锚具内部CFRP筋与环氧树脂砂浆界面粘结—滑移本构模型。研究表明:增大锚具内倾角和锚固长度可提高锚具极限荷载,平均粘结强度随锚具内倾角的增大呈增大趋势,临界锚固长度随试件锚具内倾角的增大呈减小趋势,采用回归公式计算的平均粘结强度值与试验实测值比较接近;锚固长度是影响界面粘结剪切刚度的主要因素;锚固长度和锚具内倾角可一定程度提高界面抗滑移能力,损伤发展后期,锚固长度越大,损伤速率越慢;推导出的锚具内CFRP筋与环氧树脂砂浆的粘结—滑移本构关系模型适用性较好。     

套筒内锈蚀钢筋与灌浆料黏结性能试验研究

为了研究钢筋锈蚀对灌浆套筒接头连接性能的影响,通过对 20个进行人工锈蚀的试件开展拉拔试验,获得灌浆套筒内不同直径的钢筋在不同锈蚀率情况下的破坏形态、锚固内部钢筋应变和荷载滑移曲线. 对比分析不同直径钢筋在不同锈蚀率情况下的黏结应力分布曲线、相对滑移曲线和不同锚固位置处的黏结滑移曲线. 通过试验结果和理论分析,发现随着...     

含FRP约束环钢筋锚固性能试验

目的研究含FRP约束环的钢筋锚固连接性能,为后续此种套筒连接的钢筋搭接试验研究做准备.方法对66个试件进行静力拉伸试验,试验中主要考虑钢筋直径、约束环直径、约束环壁厚、混凝土强度以及锚固长度等参数的影响,对试验构件的破坏形态以及应力应变曲线进行分析.结果钢筋最小锚固长度为0. 8倍钢筋基本锚固长度时,仍然可以保证钢筋的锚固性能; FRP约束环与内部灌浆料及外围混凝土之间未发生相互滑移及局部破坏的现象.结论含FRP约束环的灌浆钢筋连接技术是一种连接性能可靠、工艺简单、经济效益突出,适合于建筑工业化的预制装配式混凝土结构钢筋连接技术.     

钢丝绳搭接锚固和孔道注胶锚固的性能试验

提出预应力钢丝绳加固钢筋混凝土框架节点的加固方法,通过绳扣进行钢丝绳搭接锚固性能试验及钢丝绳孔道注胶搭接锚固的拉拔试验,验证搭接锚固方法的可行性.由试验结果分析可知,采用两端分别拧紧绳扣的方法可实现对已完成预应力张拉的钢丝绳的临时搭接锚固;采用密封孔道水平压力注胶的施工方法可保证胶体充满孔道确保施工质量;试验中采用的植筋胶对钢丝绳具有较好的锚固效果,可在较小锚固长度的情况下保证钢丝绳拉断而无明显滑移.     

并筋黏结锚固性能试验研究

针对并筋后钢筋与混凝土之间的有效接触面积减小、黏结性能相对变差的问题,通过57个拉拔试件和6个半梁式试件的并筋黏结锚固试验,研究了并筋的黏结锚固性能.试验中考虑了并筋根数、钢筋直径、混凝土强度、锚固长度等因素对并筋黏结滑移性能的影响.试验结果表明:并筋根数越多,名义黏结强度降低;试验方式、锚固长度、钢筋直径、混凝土强度、钢筋位置等因素对并筋黏结强度的影响与这些因素对单根钢筋黏结强度的影响相似,可以引用单根钢筋的试验研究结果分析并筋的黏结锚固性能.基于各国规范黏结强度经验公式和本文的试验数据分析,建议二并筋、三并筋的等效钢筋直径分别取值1.41和1.73.当保护层厚度减小时,可适当延长并筋的锚固长度.     

废弃玻璃集料混凝土与钢筋粘结性能试验

为揭示玻璃混凝土与钢筋的粘结锚固规律,采用中心拉拔试验方法,研究分别使用粗玻璃和细玻璃取代混凝土中粗骨料和细骨料对混凝土与钢筋的粘结强度的影响.试验结果表明:废弃玻璃粗骨料混凝土试件与普通骨料混凝土试件的极限粘结强度相当;废弃玻璃细骨料混凝土试件的极限粘结应力较普通混凝土试件的极限粘结应力有很大的提高;废弃玻璃骨料钢筋混凝土具有较好的锚固延性;废弃玻璃细骨料混凝土试件中,钢筋与混凝土达到极限粘结应力时发生的相对滑移与普通骨料混凝土相近;废弃玻璃粗骨料混凝土试件中,钢筋与混凝土达到极限粘结应力时发生的相对滑移大于普通骨料混凝土.     

高温后植筋黏结滑移力学性能试验

对在不同受热温度和不同加载制度下混凝土构件中2种锚固长度植筋的黏结滑移力学性能进行了试验.植筋的锚固长度分别为7倍和15倍植筋直径,受热温度分别为50℃,80℃,150℃和200℃.加载制度考虑单向拉拔和反复加载.分析了加载制度、锚固长度和加热温度对植筋试件的极限黏结应力和极限滑移的影响.结果表明,不同条件对植筋试件的黏结滑移力学性能有显著影响.根据试验结果给出了高温后植筋试件黏结应力的计算方法.     

钢丝网砂浆层和附加肋提升嵌入式复材筋锚固性能试验研究

为提高嵌入式加固法中复材筋的锚固性能,避免嵌筋处剥离破坏的过早发生,提出了对结构构件端部锚固区联合运用外覆钢丝网砂浆防护层和设置复材筋附加肋的增强锚固方法.通过20个构件的直接拉拔试验,分析了钢丝网砂浆防护层厚度、复材筋附加肋数量、槽道黏结剂材料类型和复材筋种类等主要参数对嵌入式复材筋锚固性能的影响.试验结果表明,附加肋与钢丝网砂浆防护层联合增强锚固的方法可显著提升嵌入式复材筋的锚固性能,且对表面刚度和横向抗剪强度较高的CFRP筋试件的提升效果较BFRP筋试件更显著,对原有黏结性能较弱的砂浆槽道黏结剂试件的提升幅度较树脂黏结剂试件更大.钢丝网砂浆防护层的锚固方法对锚固承载力的贡献较附加肋锚固方法更大,该方法可改变试件的破坏形态,有效地避免复材筋剥离破坏的发生.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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-