钢筋桁架楼承板在现浇混凝土结构中的应用

主要阐述了钢筋桁架楼承板在现浇混凝土结构应用过程中的施工要点以及难点,指出采用钢筋桁架与镀锌底板结合的模式替代模板和部分钢筋,省去了全部的模板和部分方木的使用,既节约了大量劳动力,又保护了环境,具有较为深远的社会和经济意义。     

Experimental investigation of deck plate system with non-welding truss type deformed steel wires (tox deck plate slab)

On the bases of a decreased construction period and convenience of construction, the steel deck plate system has been widely used in the construction field in Korea. In particular, due to its good stiffness and economic considerations, the steel-wire-integrated deck plate system (or truss deck plate system) has become very popular in recent years. But while it offers many advantages, the truss deck plate system has a critical defect: rust forms in the welding joints between the lattice steel wire and the deck plate, resulting in the cracking of these welding joints and water leakage. To address these problems, the TOX deck plate system, a new type of truss deck plate system that does not require welding and does not rust, is proposed in this paper. Tests have been conducted on 15 specimens to evaluate the structural safety of the proposed deck plate system during the construction stage. The test parameters were as follows: the depth of the slab, the length of the span, the diameters of the top, bottom, and lattice steel wire, and the material properties of the zinc-coated steel sheets. The test results show that the TOX deck plate system can guarantee structural safety owing to its deflection and strength.     

Application of steel sheet to the toe boards

The scaffold system have been used to assist the smooth construction works and to assure the safety of workers. The toe boards is one of the scaffold elements. It has been applied for workers and constructional materials on a scaffold deck to prevent the falling down. In this paper, thin steel sheets were applied to the toe boards to reduce the self weight. The proposed boards were designed under the recommendation of the temporal construction elements. Also, the wind effects were considered in designing the proposed toe board. The applied design load was the horizontal load from the scaffold deck or the load perpendicular to the scaffold deck. The proposed toe boards were examined numerically by use of the finite element method and experimentally by the loading tests. From both numerical and experimental results, the performance of the thin steel toe board proposed here was confirmed.     

钢纤维混凝土配合比的验证及施工质量控制

通过施工实例,介绍了高速公路桥面采用钢纤维混凝土铺装时,原材料的检验、配合比验证、施工中质量控制及操作要点,实践证明:采用该桥面铺装形式不仅节省了维护和养护费用,而且延长了桥面的使用寿命。     

碳纤维布加固钢结构的黏结性能研究

与传统的钢结构加固方法相比,粘贴碳纤维布加固钢结构具有很大的优势和应用前景,如不会导致严重的应力集中、不会产生残余应力、施工方便、维护费用低等。碳纤维布与钢结构之间的黏结性能直接影响加固效果,但是目前国内对这方面的研究还未涉足。本文对粘贴碳纤维布加固钢板进行了静力拉伸试验,采用高强型和高模型碳纤维布及不同的端部锚固措施,考察了未损伤钢板和损伤钢板加固后的效果。得到了加固试件的屈服荷载和极限荷载,并对不同的破坏形式进行了分析。试验结果表明,粘贴碳纤维布加固能明显提高钢构件的屈服荷载。测量了碳纤维布的应变分布,得到了碳纤维布与钢板之间的黏结应力分布和碳纤维布的有效黏结长度,并与理论公式的计算结果进行了对比,二者吻合较好。     

Fatigue behavior and statistical evaluation of the stress category for a steel-concrete composite bridge deck

The maintenance cost of bridges is rapidly increasing since many existing bridges are deteriorating or reaching their design life all over the world. Moreover, as many long-span bridges are under construction and planning in Korea, research and development on bridge decks with high load-resistance capacity as well as high fatigue strength has become a growing concern. This research gives experimental results of the fatigue behavior of a new-type of steel-concrete composite bridge deck being developed under such circumstances. The proposed composite bridge deck consists of corrugated steel plate, welded steel ribs, stud shear connectors, and reinforced concrete filler. Fatigue tests were conducted under a four-point bending test with four different stress ranges in constant amplitude. In order to determine the influence of the concrete filling, fatigue tests on partial steel specimens containing only plain corrugated steel plates were performed in advance. The partial steel specimens and the steel-concrete composite deck specimens both showed fatigue failure in the tension part concerning the fillet welding part between the corrugated steel plate and steel rib. Finally, the stress category of the fillet welding part of each specimen is evaluated based on a statistical approach of Albrecht’s probability model. The research concludes that the fatigue behavior of such steel-concrete composite decks under sagging moment can be estimated based on the classical S-N approach, focusing on steel components.     

不锈钢复合钢板在铁路钢桥上的应用技术

我国高速铁路钢桥均采用正交异性板钢桥面有碴线路。为提高钢桥面的防腐与使用寿命,合肥铁路枢纽南环线钢桁梁的桥面板采用了具有较高的强度、塑性、韧性、疲劳性能及优良抗腐蚀性能的321-Q345q-D不锈钢复合钢板。针对钢桥面系结构设计特点及制作与安装工艺需要,依据TB10212-2009《铁路钢桥制造规范》、GB/T13148-2008《不锈钢复合钢板焊接技术要求》,对321-Q345q-D不锈钢复合钢板进行焊接工艺试验,其试验结果(数据)均满足设计与施工要求。经对不锈钢复合钢板的钢桥面制作与安装实践,对铁路钢桥推广应用不锈钢复合钢板提出改进建议。     

六奉公路大治河桥系杆临时索组合牵引施工技术

大治河桥为主跨120m的下承式钢管混凝土拱桥,其桥拱安装采用"先拱后梁"的施工工艺,通过安装系杆临时索来平衡主拱安装完成后逐步加载所产生的水平推力。通过该桥系杆临时索的安装及初张拉施工实例,讲述利用组合牵引施工技术,进行系杆临时索的安装和初张拉的施工工艺及其技术要点。采用组合牵引技术进行系杆临时索的施工,在保证质量和安全的同时降低了成本。     

Shear capacity and tension capacity of arc-spot welds for multi-overlap deck panels

Arc-spot welds fabricated in multi-overlap configurations are found in roof deck construction when steel sheets are stacked at a sidelap or endlap. A welding technique that maximizes the quality of arc-spot welds fabricated through several layers of thick sheets is presented. Weld specimens were fabricated through 1, 2 or 4 layers of steel sheets with thicknesses ranging from 0.76 to 1.52 mm (22 to 16 gauge). The most important factors to control during the welding are the current (high intensity), the electrode type (E4311) and the welding technique. Various sheet steel/weld configurations found in roof deck construction were included. Adequate weld quality could be achieved in all cases except that welds were undersized when the ratio of the thickness of the underlying material to total sheet thickness was less than 0.7. A total of 72 tension tests and 107 shear tests were completed. Of those, 31 shear specimens were loaded with a reversed cyclic protocol to examine the behaviour of arc-spot welds subject to seismic loading. All other specimens were loaded under monotonically increasing displacement. The results were compared with the provisions of the CSA S136 North American Specification for the Design of Cold-Formed Steel Structural Members. The CSA S136 equations for shear and tension resistance of arc-spot welds are generally conservative, even for welds fabricated through multi-overlap configurations with total sheet steel thicknesses exceeding the 3.81 mm limit. Nonetheless, modifications to the equation for the effective diameter and to Equations E2.2.1.2-2, E2.2.2-1, and E2.2.2-2 are recommended.     

海南洋浦大桥桥面吊机设计技术研究

针对海南洋浦大桥（跨海湾特大桥,主跨460m）中跨440m工字钢结合梁施工的难点,自行设计贝雷梁桥面吊机,实现对工宇钢结合梁整体吊装以及桥面板的吊装,既能缩短工期,也能减少施工成本,并对施工安全更有保障,对以后大跨度斜拉桥的节段施工具有非常重要的指导意义。     

Development of fatigue test method and improvement of fatigue life by new functional steel plates for welding of trough rib and deck plate of orthotropic decks

Under heavy traffic conditions, some fatigue cracks have been found at welding joints between U-shaped ribs “trough ribs” and deck plates. Fatigue cracks along thickness direction of deck plate from root tip are important because visual crack detection from outside is limited. In this paper, new functional steel plates with initiation resistance of fatigue crack at weldment and propagation resistance at base material are applied to deck plate to evaluate improvement of fatigue life. We conducted fixed-point fatigue tests with real scale partial models consisted with one trough rib and a transverse girder, and the elastic FEM (Finite Element Method) analysis corresponding to the fatigue test specimen. Based on these results, we studied the fatigue properties which focused on the difference between conventional steel plates and newly developed steel plates, FCA (Fatigue Crack Arrester). Fatigue cracks were initiated from root tip of welded joints between a trough rib and a deck plate. It is clarified that FCA steel plates instead of conventional steel plates can improve the fatigue life under the same welding conditions. This improvement effect becomes much clearer in the high cycle region, which is noticeable at the operation and management stage of bridges.     

CFRP加固含混合型边裂纹钢板的疲劳性能试验研究

为研究碳纤维增强复合材料(CFRP)对含初始边裂纹钢板疲劳性能的改善效果,使用MTS试验机对未加固及CFRP材料加固后的含边裂纹钢板进行疲劳试验,比较了裂纹形式、钢板初始损伤度、CFRP粘贴面以及CFRP材料种类(CFRP布与CFRP板)对钢板疲劳寿命的影响.共设计制作了3个未加固试件、3个CFRP布双面加固试件、3个...     

Verzinkte Bauteile im Kontakt mit Spanngliedern

Galvanized Elements in Contact with Prestressing Steel In order to clarify under which practical conditions real risks for hydrogen‐induced stress corrosion cracking of prestressing steels in contact with galvanized elements exist laboratory investigations in aqueous solutions and concrete as well as tests with stressed prestressing steels were carried out. While different distances between steel and zinc (cathode and anode) showed only a negligible influence on the polarisation of the steel a significant dependence on the area ratio steel/zinc was observed. A critical area ratio of 10:1 can be defined above which polarisation of the steel to hydrogen evolution potentials is unlikely. The results obtained in the laboratory concerning the critical area ratio were confirmed by on‐site investigations in a precasting plant. Exposure tests with hydrogen loading did not lead to fractures during the testing time for approved prestressing steels. The characteristic mechanical values determined immediately after the hydrogen loading tests did not show significant changes. Thus, an indirect contact between prestressing steels and galvanized elements can be estimated as uncritical. But a direct contact has to be excluded by compliance with DIN 1045‐1, i.e minimal distance of 2 cm between prestressing steel and galvanized elements.     

CFRP与钢材的粘结性能试验研究

与传统的钢结构加固方法相比,粘贴CFRP加固钢结构具有明显的优势。CFRP与钢结构之间的粘结性能直接影响加固效果,但是目前国内对这方面的研究还很少。从众多的粘结材料中优选出适合于粘贴CFRP加固钢结构的粘结剂,设计相应的试件,对CFRP与钢材之间的粘结强度和粘结耐久性进行试验。试验结果表明:选用的3种粘结剂可以作为粘贴CFRP加固钢结构的粘结材料,性能满足设计要求。对粘贴碳纤维布加固钢板进行静力拉伸试验,测量碳纤维布的应变分布,得到碳纤维布与钢板之间的粘结应力分布和碳纤维布的有效粘结长度。并与理论公式的计算结果进行了对比,二者吻合较好。     

天津开启桥钢箱梁半支架悬拼施工技术

天津海河开启桥为双叶立转式开启桥,其跨径、开启角度、桥面宽度较大,根据结构力学特点和现场通航环境,提出半支架悬拼装方法,将架设机、临时钢管支撑、悬臂拼装等传统桥梁施工方法结合,以适应开启桥施工的现场通航条件及施工过程的受力特征,钢箱梁吊运设备利用率高,可缩短施工周期,节约施工成本,取得了良好的社会经济效益。     

轻钢建筑檩条材料的选择与应用

回顾轻钢工业建筑檩条原材料近15年的发展过程,比较屈服强度为345MPa的镀锌卷在不同标准下对应的钢材牌号及性能;提出檩条用镀锌卷材材料强度、镀锌量、表面处理方式的选用方法及验收标准;总结镀锌卷材及成品檩条在实际生产、储存、运输中的常见问题和相应的防护措施。     

几种典型钢桥面沥青铺装方案分析

介绍了几种典型的钢桥面铺装方案的主要特点及病害形式,并从材料性能、施工工艺和工程造价方面进行了详细的对比,最后分析了环氧沥青混凝土的优越性及其在应用中存在的问题,可为钢桥面铺装方案的选择提供一定的参考依据。     

Experimental study and numerical analysis on mechanical behavior of T-shape stiffened orthotropic steel-concrete composite bridge decks

A new-type of orthotropic steel-concrete composite bridge deck system was developed, by casting the concrete overlay on the top of the orthotropic steel deck ribbed with T-shape steel members. To study its mechanical behavior (in terms of failure mode, load-deflection relationship, concrete crack initiation and propagation, strength, stiffness and so on), two new-type orthotropic steel-concrete composite bridge decks with different section dimensions were experimentally investigated and two reference decks (reinforced concrete deck and orthotropic steel deck) were also involved in the research for comparison. For the two new-type orthotropic steel-concrete composite decks, the average value of ultimate loads per width is 885.7kN, which is 2.35 and 1.61 times of that of the concrete and steel reference decks with almost the same section height. Experimental results proved that the composite deck can effectively control the crack initiation and propagation in the concrete and postpone the yielding of the steel bars and steel plates, due to the composite action between the concrete overlay and the underlying steel plate. Furthermore, the Finite Element (FE) model of the orthotropic steel-concrete composite deck was developed and validated by test results. A parametric study is conducted regarding to the stiffness of shear studs. With the validated FE model, stress distribution in the underlying steel plate and T-shape stiffeners and development of concrete cracking in the concrete overlay were characterized at different load levels.     

套接紧定式镀锌钢导管在建筑工程中的应用

结合工程实例，介绍套接紧定式镀锌钢导管的设计目的和施工优点，并从施工工艺、施工方法、质量控制等方面进行阐述，着重进行了套接紧定式镀锌钢导管（JDG）与传统焊接钢管（SC）的经济技术分析，总结出其在工程施工中产生的实际意义和经济效益。     

Component sizing approach for the sandwich plate system

The sandwich plate system (SPS) is a bridge deck system consisting of steel face plates bonded to a rigid polyurethane core. SPS bridges are typically constructed as a series of pre-fabricated SPS deck panels compositely connected with traditional steel girders. The decks are thin, lightweight and modular, and can be tailored to numerous applications including both new bridge and rehabilitated bridges.

With new system, there exist hurdles in the implementation; for SPS, the primary challenge is the lack of an established design method for the panel cross-sections. Presented herein is a method for sizing SPS panel sections for bridge applications. This method is limited to the selection of steel plate and core dimensions, subjected to American Association of State Highway and Transportation Officials (AASHTO) limit states of serviceability, strength and fatigue and does not consider connections or bond aspects of the system. The sizing approach considers the deck panels as plates with variable boundary conditions subjected to the loading conditions of the AASHTO Load Resistance Factored Design (LRFD) bridge design specification. Results from this study indicate that the component sizing for SPS deck panels is controlled by stiffness and that plates selected to satisfy the AASHTO limiting deflection criterion will also be adequate for the remaining serviceability, strength and fatigue limit states.