土木工程外文文献及翻译

Original Article

Impact of crack width on bond: confined and unconfine

d rebar

David https://www.sodocs.net/doc/1012610495.html,w1, Denglei Tang2, Thoma

s K. C.Molyneaux3 and Rebecca Gravina3

(1)School of the Built Environment, Heriot Watt University, Edinburgh, EH14

4AS, UK

(2)VicRoads, Melbourne, VIC,

Australia

(3)School of Civil, Environmental and Chemical Engineering, RMIT

University, Melbourne, VIC, 3000, Australia

David W. Law

Email:

https://www.sodocs.net/doc/1012610495.html,w@https://www.sodocs.net/doc/1012610495.html,

Received: 14January2010Accepted: 14Decemb er2010Published online: 23December2010 Abstract

This paper reports the results of a research project comp aring the effect of surface crack width and degree of corrosi on on the bond strength of confined and unconfined deforme d 12 and 16mm mild steel reinforcing bars. The corrosion was induced by chloride contamination of the concrete and

an applied DC current. The principal parameters investigated were confinement of the reinforcement, the cover depth, bar diameter, degree of corrosion and the surface crack width. T he results indicated that potential relationship between the cra ck width and the bond strength. The results also showed an increase in bond strength at the point where initial surface cr acking was observed for bars with confining stirrups. No suc h increase was observed with unconfined specimens.

Keywords:bond;corrosion;rebar;cove

r;crack width;concrete

1 Introduction

The corrosion of steel reinforcement is a major cause of the deterioration of reinforced concrete structures throughout

the world. In uncorroded structures the bond between the st eel reinforcement and the concrete ensures that reinforced co ncrete acts in a composite manner. However, when corrosion of the steel occurs this composite performance is adversely affected. This is due to the formation of corrosion products on the steel surface, which affect the bond between the steel and the concrete.

2 Experimental investigation

2.1 Specimens

Fig.1Beam end specimen

Deformed rebar of 12 and 16mm diameter with cover of three times bar diameter were investigated. Duplicate sets of confined and unconfined specimens were tested. The con fined specimens had three sets of 6mm stainless steel stirr ups equally spaced from the plastic tube, at 75mm centres.

This represents four groups of specimens with a combin ation of different bar diameter and with/without confinement. The specimens were selected in order to investigate the infl uence of bar size, confinement and crack width on bond stre ngth.

2.2 Materials

Materi al Cement w/c Sand

10 mm

washed

aggrega

te

7 mm

washed

aggrega

te

Salt Slump

Quantit y 381 kg/

m3

0.4

9

517 kg/

m3

463 kg/

m3

463 kg/

m3

18.84 kg/

m3

140 ± 25 mm

(1)

where is the bond strength for grade 40 concrete, τexptl is the experimental bond strength and f c is the experi mental compressive strength.

The tensile strength of the Φ12 and Φ16mm steel ba rs was nominally 500MPa, which equates to a failure load of 56.5 and 100.5kN, respectively.

2.3 Experiment methodology

Fig.2Accelerated corrosion system

When the required crack width was achieved for a parti cular bar, the impressed current was discontinued for that ba

r. The specimen was removed for pullout testing when all fo ur locations exhibited the target crack width. Average surface crack widths of 0.05, 0.5, 1 and 1.5mm were adopted as the target crack widths. The surface crack width was measu red at 20mm intervals along the length of the bar, beginni ng 20mm from the end of the (plastic tube) bond breaker using an optical microscope. The level of accuracy in the m easurements was ±0.02mm. Measurements of crack width were taken on the surface normal to the bar direction regardl ess of the actual crack orientation at that location.

Fig.3Pull-out test, 16mm bar unconfined

Fig.4Schematic of loading. Note: only test bar show n for clarity

3 Experimental results and discussion

3.1 Visual inspection

While each specimen had a mean target crack width for each bar, variations in this crack width were observed prior to pull out testing. This is due to corrosion and cracking b eing a dynamic process with cracks propagating at different r ates. Thus, while individual bars were disconnected, once the target crack width had been achieved, corrosion and crack p ropagation continued (to some extent) until all bars had achi eved the target crack width and pull out tests conducted. Thi s resulted in a range of data for the maximum and mean cr ack widths for the pull out tests.

Fig.5Typical crack patterns

Fig.6Longitudinal cracking after pull-out

Fig.7Diagonal cracking after pull-out

The bars were initially (precasting) cleaned with a 12% hydrochloric acid solution, then washed in distilled water and neutralized by a calcium hydroxide solution before being w ashed in distilled water again. Following the pull-out tests, th e corroded bars were cleaned in the same way and weighed again.

The corrosion degree was determined using the followin g equation

where G 0 is the initial weight of the steel bar before corrosion, G is the final weight of the steel bar after remova l of the post-test corrosion products, g 0 is the weight per u nit length of the steel bar (0.888 and 1.58g/mm for Φ12 and Φ16mm bars, respectively), l is the embedded bond length.

3.2 Bond stress and crack width

Fig.10Mean crack width versus bond stress for 16 mm bars

Fig.11Mean crack width versus bond stress for 1

2mm bars

Fig.12Maximum crack width versus bond stress for 16mm bars

Fig.13Maximum crack width versus bond stress for 12mm bars

Table2Best fit parameters, crack width versus bond

There was also a significantly better fit for the unconfin ed specimens than the confined specimens. This is consistent with the observation that in the unconfined specimens the b ond strength will be related to the bond between the bars an d the concrete, which will be affected by the level of corros ion present, which itself will influence the crack width. In c onfined specimens the confining steel will impact upon both the bond and the cracking.

3.3 Corrosion degree and bond stress

Fig.14Bond stress versus corrosion degree, 12mm bars, unconfined specimen

Significantly larger crack widths were observed for the unconfined specimens, compared to the confined specimens with similar levels of corrosion and mass lost. The largest o bserved crack for unconfined specimens was 2.5mm compa red to 1.4mm for the confined specimens. This is as expe cted and is a direct result of the confinement which limits t he degree of cracking.

3.4 Effect of confinement

The data is perhaps unexpected as it could be anticipate d that the corrosion products would lead to an increase in b ond due to the increase in internal pressures, caused by the corrosion products increasing the confinement and mechanical interlocking around the bar, coupled with increased roughnes s of the bar resulting in a greater friction between the bar a nd the surrounding concrete. However, these pressures would then relieved by the subsequent cracking of the concrete, w hich would contribute to the decrease in the bond strength a s crack widths increase. A possible hypothesis is that due to the level of cover, three times bar diameter, the effect of c onfinement by the stirrups is reduced, such that it has little i

mpact on the bond stress in uncracked concrete. However, o nce cracking has taken place the confinement does have a b eneficial effect on the bond.

It may also be that the compressive strength of the con crete combined with the cover will have an effect on the bo nd stresses for uncorroded specimens. The data presented her e has a cover of three times bar diameter and a strength of 40MPa, other research ranges from 1.5 to four times cover with compressive strengths from 40 to 77MPa.

3.5 Comparison of 12 and 16mm rebar

The maximum bond stress for 16mm unconfined bars was measured at 8.06MPa and for the 12mm bars it w as 8.43MPa. These both corresponded to the control speci mens with no corrosion. The unconfined specimens for both the 12 and 16mm bars showed no increase in bond stress due to corrosion. For the confined specimens the maximum bond stress for the control specimens were 7.29MPa for t he 12mm bars and 6.34MPa for the 16mm bars. The maximum bond stress for both sets of confined specimens c orresponded to point of the initial cracking. The maximum b ond stresses were observed at a mean crack width of 0.0

1mm for the 12mm bars and 0.28mm for the 16m m bars. The corresponding bond stresses were, 8.45 and 7.2 0MPa. Overall the 12mm bars displayed higher bond str

esses compared to the 16mm bars at all crack widths. Thi s is attributed to a different failure mode. The 16mm spec imens demonstrate splitting failure while the 12mm bars b ond failure.

3.6 Effect of casting position

Fig.15Bond stress versus mean crack width for 1

2mm bars, top and bottom cast positions, confined specime n

4 Conclusions

A relationship was observed between crack width and b ond stress. The correlation was better for maximum crack wi dth and bond stress than for mean crack width and bond str ess.

Confined bars displayed a higher bond stress at the poin t of initial cracking than where no corrosion had occurred. As crack width increase the bond stress reduced significantly.

Unconfined bars displayed a decrease in bond stress at i nitial cracking, followed by a further decrease as cracking in creased.

Top cast bars displayed a higher bond stress in specime ns with no corrosion. Once cracking had occurred no variati on between top and bottom cast bars was observed.

The 12mm bars displayed higher bond stress values th an 16mm with no corrosion, control specimens, and at sim ilar crack widths.

A good correlation was observed between bond stress an d degree of corrosion was observed at low levels of corrosio n (less than 5%). However, at higher levels of corrosion no correlation was discerned.

Overall the results indicated a potential relationship betw een the maximum crack width and the bond. Results shown herein should be interpreted with caution as this variation ma y be not only due to variations between accelerated corrosio n and natural corrosion but also due to the complexity of th e cracking mechanism in reality.

中文译文：

约束和无约束的钢筋对裂缝宽度的阻碍

收稿日期：2010年1月14 纳稿日期：2010年12月14日线上发表时刻：2010年1月23日

摘要

本报告公布了局限约束和自由的变形对粘结强度12、16毫米钢筋的表面腐蚀程度和裂纹阻碍的比较结果。腐蚀是氯化物污染的混凝土的诱导和外加直流电流的引起的。调查的要紧参数有钢筋剥离，爱护层厚度，钢筋直径，腐蚀程度和表面裂

缝宽度。结果表明了裂缝宽度和粘结强度之间的潜在关系。同时还发觉在围箍筋处发觉表面裂纹的地点粘结强度增加，而无侧限的样本中没有观看到粘结强度增加。

关键词：粘结；腐蚀；螺纹钢；爱护层；裂缝宽度；混凝土

引言

在世界各地，钢筋的腐蚀是钢筋混凝土结构的恶化的重要缘故。在未腐蚀的结构中钢筋和混凝土之间的粘结使钢筋混凝土处于有利状态。然而，当钢铁的腐蚀发生时，会对这种主动性能产生不利阻碍。这是由于钢表面形成了腐蚀产物，从而阻碍了钢和混凝土之间的粘结。

钢筋混凝土恶化是由钢筋和形成的膨胀腐蚀产物造成的

局部缺失。这种情形的恶化在许多方面阻碍结构;膨胀产品的产生造成混凝土的拉应力，这可能会导致混凝土爱护层开裂和剥落的。这种开裂可导致更严峻的恶化和进一步的腐蚀。它也能够导致在混凝土爱护层的强度和刚度的缺失。腐蚀产物也能够阻碍混凝土与钢筋之间的粘结强度。最终腐蚀减少钢筋截面面积，阻碍钢筋的延展性和承载能力，从而最终阻碍结构适用性和结构承载力[12，25]。

以往的研究调查腐蚀对粘结的阻碍[2-5，7，12，20，23-25，27，29]，提出了数据模型[4，6，9，10，18，19 24，29]。本研究要紧研究腐蚀（钢材质量缺失）水平或电流密度程度（腐蚀电流在加速测试中的应用）和裂缝宽度之间的关系，或粘结强度和腐蚀程度之间的关系。其他研究已调查的锈蚀力学性能

[1，11]和摩擦特性[13]。然而，专门少有人研究都集中在裂缝宽度与粘结[23，26，28]之间的关系上，此参数易与实际结构相联系。

加大钢筋的腐蚀导致生成铁氧化物，它的体积大于原钢材。这种扩张造成周围的混凝土内的拉应力，最终导致混凝土爱护层开裂。一旦开裂发生，混凝土紧箍力就会缺失。这表明粘结能力的缺失可能与纵向裂缝宽度有关[12]。然而，以混凝土的剥离能够在一定程度上抵消粘结力的缺失。最新研究要紧与剥离样本有关。本文报道的一项研究比较了有侧限和无侧限样本的粘结力缺失。

2.实验研究

2.1样本

梁端样本[28]被选定为这项研究的研究对象。这种撤去偏心或“梁端”模式样本以一个典型的简支梁锚固区的粘结长度支撑。样本的矩形截面投在纵向钢筋的各处，如图1。由于没

有增强下方横反应的钢筋，试样提供了一个80毫米的塑料管，以确保粘结强度（横向）压缩力超过那个长度的钢筋。

图1梁端试样

试验调查了由3倍直径厚的爱护层爱护的12和16毫米直径的钢筋。重复测试有侧限和自由样本。在密闭的塑料管中有3套6毫米的不锈钢箍筋从其间穿过，在75毫米中心。

这代表了四组不同钢筋直径和有侧限/无约束的样本。以调查钢筋规格，混凝土剥离和裂缝宽度对粘结强度的阻碍。

2.2材料

配合比设计，如表1所示。水泥是I 型硅酸盐水泥，骨料为玄武岩，容重2.99。按照AS 1141— 2000进行粗、细集料的制备。拌合按照AS 1141—1994进行。测试前水浴养护28天。

表1混凝土配合比设计 材料 水泥 w/c 砂 10mm 集

料

7mm 集料 盐含量 塌落度 结果 381kg/m 3 0.4 517

kg/m 3 kg/m 3 kg/m 3 kg/m 3 140±25mm

为了比较不同的混凝土抗压强度，粘结强度，Eq 。 公式1已被其他研究者用于正常化粘结强度的非腐蚀样本。 'exp 40c f ττ= 1

τ为40级混凝土的粘结强度，τexptl为实验粘结强度和Fc 是实验抗压强度。

Φ12和Φ16毫米钢筋的抗拉强度是500兆帕，分不相当于一个56.5和100.5kN的破坏载荷。

2.3实验方法

加速腐蚀已被许多作者用于重现在自然环境中发生的腐

蚀钢筋钢[2，3，5，6，10，18，20，24，27，28，30]。这些有关实验使用外加电流或干湿周期人工风化和升高温度延缓

腐蚀时刻，同时保持恶化机制处于自然状态。采纳外加电流的研究使用的电流密度在100μA/cm2与500 mA/cm2之间[2 0]。有研究表明，电流密度200μA/cm2与100μA/cm2相比，200的结果与早期时期的腐蚀更相似[21]。随着施加电流密度200μA/cm2被选定为研究使用电流，这在往常的研究中成为电流密度频谱的低端代表。然而，应慎重应用外加电流的加速腐蚀，加速过程并不完全复制在实际结构中所涉及的机制。在加速测试中不承诺违抗自然的进展，并有可能在表面上更平均腐蚀。腐蚀率也可能会阻碍腐蚀的产品，这些产品可能会形成不同的氧化状态，这可能会阻碍粘结强度。

钢筋作为阳极和四个碳钢金属板固定在表面作为阴极。金属板和混凝土之间放置海绵（用盐水喷洒）提供足够的接触，如图2。

图2加速腐蚀系统

当裂缝宽度要求需适应专门钢筋时应该终止施加外加电流。当所有四个位置显现规定的裂缝宽度，试样就会被拆除撤离测试。平均表面裂缝宽度0.05，0.5，1和1.5毫米作为目标裂缝宽度。表面裂纹宽度沿钢筋长度测量间隔20mm，从约束（塑料管）末端开始20mm用断路器光学显微镜测量。测量精度为±0.02毫米。从钢筋表面测量裂缝宽度，不考虑裂缝实际方位在何处。

粘结强度测试通过手动操作液压千斤顶和一个定制的试验装置，如图3所示。加载方案见图4。长80毫米的塑料管在末端提供了一个横向反应的具体部分，以确保粘结强度可不能因为内力（压力）提升而增加。样本定位使轴向力，适用于被测试的钢筋。给样本足够刚性的约束能够确保在加载过程中最小的旋转或扭曲。

图3拉出测试，16毫米钢筋不承压

图4加载示意图。注：只测试显示棒

3实验结果与讨论

3.1目视检查

加速腐蚀时期后，检查每个样本的裂缝的位置，平均裂缝宽度和最大裂缝宽度（第2.3款）。

尽管每个钢筋样本都有平均目标裂缝宽度，然而裂缝宽度的变化在观看前拉出测试。这是由于腐蚀和开裂是一个动态的过程，裂缝是以不同的速度传播的。因此，当个不钢筋被拉断的时候，一旦目标裂缝宽度差不多达到，腐蚀和裂纹在一定程度上连续扩展，直到所有的钢筋已达到目标的裂缝宽度，再终止试验进行。这产生了一系列的最大裂缝和终止测试时的平均裂缝宽度数据。

视觉检测的样本显示了三个时期的裂解过程。初始裂缝发生在专门短的时刻内，通常在几天之内产生。在此之后，大多数裂缝以一个恒定的速度增长，直到3-4周后首次开裂，他们达到1毫米。裂缝达到了1毫米后，它们的增长速度专门缓慢，甚至一些裂缝一点都不增加。侧限和自由的样本表面裂纹往往发生在侧面（如对侧的顶部或底部），并沿钢筋方向进展。一

样情形下无侧限的样本只有仅有的一部分裂缝，而自由的样本裂缝的进展却十分常见，观看到的裂缝垂直对齐下边，垂直向下侧相邻的链接，如图5。

图5典型裂纹模式

在拉出测试时最常见的侧限和自由的故障是剥离失败，这是由于随着在荷载作用下腐蚀的扩大形成裂缝，最终导致右上角/边缘剥落，如图6。然而一些侧限的样本，存在第二种破坏模式，在侧墙对角线显现裂缝，如图7。在腐蚀时期，这些裂缝的显现与观看到的垂直裂缝如上面报道的，并不有关。

图6拉出后纵向开裂

图7角开裂后拉出

钢筋最初（预制）由12％的盐酸溶液清洗，然后在蒸馏水清洗，另外蒸馏水洗涤之前由氢氧化钙溶液中和。锈蚀钢筋拉出来测试之后，以同样的方式进行清洗，并再次称重。

使用下列公式确定的腐蚀程度 ()

0R 0G -G C =100%

g l ?

其中G0是钢筋腐蚀前的初始重量，G 是最终去除腐蚀产物后的测试后的钢筋重量，g0是每单位长度的钢筋重量（Φ12和Φ16毫米钢筋分不0.888和1.58g/毫米），l 是嵌入式的键长。

图8和图9显示有不同程度的腐蚀钢筋。多数表现出可见的凹陷，类似的实际结构，如图9。然而，少数其他钢筋表现出显着的整体部分缺失，更平均的腐蚀水平，如图8，这可能是一个加速方法的功能。

图8 12毫米钢筋腐蚀、约30％的质量缺失

图9 16毫米钢筋腐蚀、约15％的质量缺失

3.2粘结应力和裂缝宽度

图10显示了16毫米的钢筋粘结应力与平均裂缝宽度的变化。图11为12毫米的钢筋的。图12和图13显示的最大裂缝宽度的数据。

图10 16毫米的钢筋平均裂缝宽度、粘结应力

图11 12毫米的钢筋平均裂缝宽度、粘结应力

图12 16毫米的钢筋最大裂缝宽度、粘结应力

图13 12毫米的钢筋最大裂缝宽度、粘结应力

数据显示12毫米箍筋样本的初始粘结强度增加，这与其他作者[12，15]的结论相同。关于16毫米箍筋样本观看到的裂缝宽度0.28和0.35毫米，然而，裂缝宽度减少了粘结应力，观看到的平均裂缝宽度为0.05毫米。

土木工程外文翻译.doc

项目成本控制 一、引言 项目是企业形象的窗口和效益的源泉。随着市场竞争日趋激烈，工程质量、文明施工要求不断提高，材料价格波动起伏，以及其他种种不确定因素的影响，使得项目运作处于较为严峻的环境之中。由此可见项目的成本控制是贯穿在工程建设自招投标阶段直到竣工验收的全过程，它是企业全面成本管理的重要环节，必须在组织和控制措施上给于高度的重视，以期达到提高企业经济效益的目的。 二、概述 工程施工项目成本控制，指在项目成本在成本发生和形成过程中，对生产经营所消耗的人力资源、物资资源和费用开支，进行指导、监督、调节和限制，及时预防、发现和纠正偏差从而把各项费用控制在计划成本的预定目标之内，以达到保证企业生产经营效益的目的。 三、施工企业成本控制原则 施工企业的成本控制是以施工项目成本控制为中心，施工项目成本控制原则是企业成本管理的基础和核心，施工企业项目经理部在对项目施工过程进行成本控制时，必须遵循以下基本原则。 3.1 成本最低化原则。施工项目成本控制的根本目的，在于通过成本管理的各种手段，促进不断降低施工项目成本，以达到可能实现最低的目标成本的要求。在实行成本最低化原则时，应注意降低成本的可能性和合理的成本最低化。一方面挖掘各种降低成本的能力，使可能性变为现实；另一方面要从实际出发，制定通过主观努力可能达到合理的最低成本水平。 3.2 全面成本控制原则。全面成本管理是全企业、全员和全过程的管理，亦称“三全”管理。项目成本的全员控制有一个系统的实质性内容，包括各部门、各单位的责任网络和班组经济核算等等，应防止成本控制人人有责，人人不管。项目成本的全过程控制要求成本控制工作要随着项目施工进展的各个阶段连续 进行，既不能疏漏，又不能时紧时松，应使施工项目成本自始至终置于有效的控制之下。 3.3 动态控制原则。施工项目是一次性的，成本控制应强调项目的中间控制，即动态控制。因为施工准备阶段的成本控制只是根据施工组织设计的具体内容确

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PA VEMENT PROBLEMS CAUSED BY COLLAPSIBLE SUBGRADES By Sandra L. Houston,1 Associate Member, ASCE (Reviewed by the Highway Division) ABSTRACT: Problem subgrade materials consisting of collapsible soils are com- mon in arid environments, which have climatic conditions and depositional and weathering processes favorable to their formation. Included herein is a discussion of predictive techniques that use commonly available laboratory equipment and testing methods for obtaining reliable estimates of the volume change for these problem soils. A method for predicting relevant stresses and corresponding collapse strains for typical pavement subgrades is presented. Relatively simple methods of evaluating potential volume change, based on results of familiar laboratory tests, are used. INTRODUCTION When a soil is given free access to water, it may decrease in volume, increase in volume, or do nothing. A soil that increases in volume is called a swelling or expansive soil, and a soil that decreases in volume is called a collapsible soil. The amount of volume change that occurs depends on the soil type and structure, the initial soil density, the imposed stress state, and the degree and extent of wetting. Subgrade materials comprised of soils that change volume upon wetting have caused distress to highways since the be- ginning of the professional practice and have cost many millions of dollars in roadway repairs. The prediction of the volume changes that may occur in the field is the first step in making an economic decision for dealing with these problem subgrade materials. Each project will have different design considerations, economic con- straints, and risk factors that will have to be taken into account. However, with a reliable method for making volume change predictions, the best design relative to the subgrade soils becomes a matter of economic comparison, and a much more rational design approach may be made. For example, typical techniques for dealing with expansive clays include: (1) In situ treatments with substances such as lime, cement, or fly-ash; (2) seepage barriers and/ or drainage systems; or (3) a computing of the serviceability loss and a mod- ification of the design to "accept" the anticipated expansion. In order to make the most economical decision, the amount of volume change (especially non- uniform volume change) must be accurately estimated, and the degree of road roughness evaluated from these data. Similarly, alternative design techniques are available for any roadway problem. The emphasis here will be placed on presenting economical and simple methods for: (1) Determining whether the subgrade materials are collapsible; and (2) estimating the amount of volume change that is likely to occur in the 'Asst. Prof., Ctr. for Advanced Res. in Transp., Arizona State Univ., Tempe, AZ 85287. Note. Discussion open until April 1, 1989. To extend the closing date one month,

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本科毕业设计 外文文献及译文 文献、资料题目：Designing Against Fire Of Building 文献、资料来源：国道数据库 文献、资料发表（出版）日期：2008.3.25 院（部）：土木工程学院 专业：土木工程 班级：土木辅修091 姓名：武建伟 学号：2008121008 指导教师：周学军、李相云 翻译日期： 20012.6.1

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土木工程专业英语翻译

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不是说富于想象力的结构设计就能够创造出伟大建筑。正相反，有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了，然而，如果没有天赋甚厚的建筑师的创造力的指导，那么，得以发展的就只能是好的结构，并非是伟大的建筑。无论如何，要想创造出高层建筑真正非凡的设计，两者都需要最好的。 虽然在文献中通常可以见到有关这七种体系的全面性讨论，但是在这里还值得进一步讨论。设计方法的本质贯穿于整个讨论。设计方法的本质贯穿于整个讨论中。 抗弯矩框架 抗弯矩框架也许是低，中高度的建筑中常用的体系，它具有线性水平构件和垂直构件在接头处基本刚接之特点。这种框架用作独立的体系，或者和其他体系结合起来使用，以便提供所需要水平荷载抵抗力。对于较高的高层建筑，可能会发现该本系不宜作为独立体系，这是因为在侧向力的作用下难以调动足够的刚度。 我们可以利用STRESS，STRUDL 或者其他大量合适的计算机程序进行结构分析。所谓的门架法分析或悬臂法分析在当今的技术中无一席之地，由于柱梁节点固有柔性，并且由于初步设计应该力求突出体系的弱点，所以在初析中使用框架的中心距尺寸设计是司空惯的。当然，在设计的后期阶段，实际地评价结点的变形很有必要。 支撑框架 支撑框架实际上刚度比抗弯矩框架强，在高层建筑中也得到更广泛的应用。这种体系以其结点处铰接或则接的线性水平构件、垂直构件和斜撑构件而具特色，它通常与其他体系共同用于较高的建筑，并且作为一种独立的体系用在低、中高度的建筑中。

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英文原文： Building construction concrete crack of prevention and processing Abstract The crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure. Keyword:Concrete crack prevention processing Foreword Concrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the

土木工程专业英语课文原文及对照翻译

土木工程专业英语课文原 文及对照翻译 Newly compiled on November 23, 2020

Civil Engineering Civil engineering, the oldest of the engineering specialties, is the planning, design, construction, and management of the built environment. This environment includes all structures built according to scientific principles, from irrigation and drainage systems to rocket-launching facilities. 土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。 Civil engineers build roads, bridges, tunnels, dams, harbors, power plants, water and sewage systems, hospitals, schools, mass transit, and other public facilities essential to modern society and large population concentrations. They also build privately owned facilities such as airports, railroads, pipelines, skyscrapers, and other large structures designed for industrial, commercial, or residential use. In addition, civil engineers plan, design, and build complete cities and towns, and more recently have been planning and designing space platforms to house self-contained communities. 土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。 The word civil derives from the Latin for citizen. In 1782, Englishman John Smeaton used the term to differentiate his nonmilitary engineering work from that of the military engineers who predominated at the time. Since then, the term civil engineering has often been used to refer to engineers who build public facilities, although the field is much broader 土木一词来源于拉丁文词“公民”。在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。 Scope. Because it is so broad, civil engineering is subdivided into a number of technical specialties. Depending on the type of project, the skills of many kinds of civil engineer specialists may be needed. When a project begins, the site is surveyed and mapped by civil engineers who locate utility placement—water, sewer, and power lines. Geotechnical specialists perform soil experiments to determine if the earth can bear the weight of the project. Environmental specialists study the project’s impact on the local area: the potential for air and

土木工程外文翻译参考3篇

学校 毕业设计（论文）附件 外文文献翻译 学号： xxxxx 姓名： xxx 所在系别： xxxxx 专业班级： xxx 指导教师： xxxx 原文标题： Building construction concrete crack of prevention and processing 2012年月日 .

建筑施工混凝土裂缝的预防与处理1 摘要 混凝土的裂缝问题是一个普遍存在而又难于解决的工程实际问题，本文对混凝土工程中常见的一些裂缝问题进行了探讨分析，并针对具体情况提出了一些预防、处理措施。 关键词：混凝土裂缝预防处理 前言 混凝土是一种由砂石骨料、水泥、水及其他外加材料混合而形成的非均质脆性材料。由于混凝土施工和本身变形、约束等一系列问题，硬化成型的混凝土中存在着众多的微孔隙、气穴和微裂缝，正是由于这些初始缺陷的存在才使混凝土呈现出一些非均质的特性。微裂缝通常是一种无害裂缝，对混凝土的承重、防渗及其他一些使用功能不产生危害。但是在混凝土受到荷载、温差等作用之后，微裂缝就会不断的扩展和连通，最终形成我们肉眼可见的宏观裂缝，也就是混凝土工程中常说的裂缝。 混凝土建筑和构件通常都是带缝工作的，由于裂缝的存在和发展通常会使内部的钢筋等材料产生腐蚀，降低钢筋混凝土材料的承载能力、耐久性及抗渗能力，影响建筑物的外观、使用寿命，严重者将会威胁到人们的生命和财产安全。很多工程的失事都是由于裂缝的不稳定发展所致。近代科学研究和大量的混凝土工程实践证明，在混凝土工程中裂缝问题是不可避免的，在一定的范围内也是可以接受的，只是要采取有效的措施将其危害程度控制在一定的范围之内。钢筋混凝土规范也明确规定：有些结构在所处的不同条件下，允许存在一定宽度的裂缝。但在施工中应尽量采取有效措施控制裂缝产生，使结构尽可能不出现裂缝或尽量减少裂缝的数量和宽度，尤其要尽量避免有害裂缝的出现，从而确保工程质量。 混凝土裂缝产生的原因很多，有变形引起的裂缝：如温度变化、收缩、膨胀、不均匀沉陷等原因引起的裂缝；有外载作用引起的裂缝；有养护环境不当和化学作用引起的裂缝等等。在实际工程中要区别对待，根据实际情况解决问题。 混凝土工程中常见裂缝及预防: 1.干缩裂缝及预防 干缩裂缝多出现在混凝土养护结束后的一段时间或是混凝土浇筑完毕后的一周左右。水泥浆中水分的蒸发会产生干缩，且这种收缩是不可逆的。干缩裂缝的产生主要是由于混凝土内外水分蒸发程度不同而导致变形不同的结果：混凝土受外部条件的影响，表面水分损失过快，变形较大，内部湿度变化较小变形较小，较大的表面干缩变形受到混凝土内部约束，产生较大拉应力而产生裂缝。相对湿度越低，水泥浆体干缩越大，干缩裂缝越易产 1原文出处及作者：《加拿大土木工程学报》

土木工程毕业设计外文翻译最终中英文

7 Rigid-Frame Structures A rigid-frame high-rise structure typically comprises parallel or orthogonally arranged bents consisting of columns and girders with moment resistant joints. Resistance to horizontal loading is provided by the bending resistance of the columns, girders, and joints. The continuity of the frame also contributes to resisting gravity loading, by reducing the moments in the girders. The advantages of a rigid frame are the simplicity and convenience of its rectangular form.Its unobstructed arrangement, clear of bracing members and structural walls, allows freedom internally for the layout and externally for the fenestration. Rig id frames are considered economical for buildings of up to' about 25 stories, above which their drift resistance is costly to control. If, however, a rigid frame is combined with shear walls or cores, the resulting structure is very much stiffer so that its height potential may extend up to 50 stories or more. A flat plate structure is very similar to a rigid frame, but with slabs replacing the girders As with a rigid frame, horizontal and vertical loadings are resisted in a flat plate structure by the flexural continuity between the vertical and horizontal components. As highly redundant structures, rigid frames are designed initially on the basis of approximate analyses, after which more rigorous analyses and checks can be made. The procedure may typically inc lude the following stages: 1. Estimation of gravity load forces in girders and columns by approximate method. 2. Preliminary estimate of member sizes based on gravity load forces with arbitrary increase in sizes to allow for horizontal loading. 3. Approximate allocation of horizontal loading to bents and preliminary analysis of member forces in bents. 4. Check on drift and adjustment of member sizes if necessary. 5. Check on strength of members for worst combination of gravity and horizontal loading, and adjustment of member sizes if necessary. 6. Computer analysis of total structure for more accurate check on member strengths and drift, with further adjustment of sizes where required. This stage may include the second-order P-Delta effects of gravity loading on the member forces and drift.. 7. Detailed design of members and connections.