Civil Engineering Design最新文献_第9页

Multiaxial and variable amplitude fatigue of concrete 混凝土的多轴变幅疲劳

Civil Engineering Design Pub Date : 2019-07-13 DOI: 10.1002/cend.201900010

Peter Heek, Peter Mark

引用次数: 4

Methods to evaluate test results based on small sample sizes 基于小样本量评估测试结果的方法

Civil Engineering Design Pub Date : 2019-05-03 DOI: 10.1002/cend.201900012

Steffen Marx, Jürgen Grünberg, Gregor Schacht

引用次数: 0

Full-scale shear capacity testing of an existing prestressed concrete bridge 某既有预应力混凝土桥梁全尺寸抗剪承载力试验

Civil Engineering Design Pub Date : 2019-04-01 DOI: 10.1002/cend.201900003

Sebastian Felix Gehrlein, Oliver Fischer

{"title":"Full-scale shear capacity testing of an existing prestressed concrete bridge","authors":"Sebastian Felix Gehrlein, Oliver Fischer","doi":"10.1002/cend.201900003","DOIUrl":"10.1002/cend.201900003","url":null,"abstract":"Due to the relatively high average age of the existing bridges, a dramatic increase both in traffic volume and axle loads and because of modified design standards, a realistic prediction of the shear capacity of existing prestressed concrete bridges with little shear reinforcement has become an important topic in German research. In 2017, the Chair of Concrete and Masonry Structures of the Technical University of Munich (TUM), supported by the Federal Ministry of Transport and Digital Infrastructure, was given the unique opportunity to conduct full-scale field tests at the Hammelburg Bridge built in 1955. According to systematic strength evaluations, many concrete bridges in Germany, especially those which were built prior to 1966, show severe (theoretical) deficits regarding longitudinal shear capacity. The results of the strength evaluation can often not be verified in the real bridges though. The primary objective of the field test therefore was to determine the actual shear capacity of existing prestressed bridges aiming at closing the gap between structural analyses and experience in regard to older concrete bridges. The article at hand presents the conceptual approach, the test set-up and the execution of the in-situ testing, the used measuring equipment and essential findings gained from the conducted full-scale experiments. Furthermore, the results are discussed and the measured maximum loads of all five tests are compared to the results of different theoretical approaches and engineering models, respectively.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"1 2","pages":"64-73"},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.201900003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80915818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Precast bridge construction with UHPFRC—Shear tests and railway bridge pilot application 预制桥梁施工uhpfrc -剪切试验及铁路桥梁试点应用

Civil Engineering Design Pub Date : 2019-03-23 DOI: 10.1002/cend.201800005

Nicholas Schramm, Oliver Fischer

{"title":"Precast bridge construction with UHPFRC—Shear tests and railway bridge pilot application","authors":"Nicholas Schramm, Oliver Fischer","doi":"10.1002/cend.201800005","DOIUrl":"10.1002/cend.201800005","url":null,"abstract":"Due to the favorable material properties, Ultra-High Performance Fiber-Reinforced Concrete (UHPFRC) opens up new potential for precast options in PC bridge construction. On that matter, this article outlines the application, the load-bearing behavior and advantages of two different possibilities: slender prestressed bridge girders and a prestressed trough-shaped bridge element. Prestressed bridge girders made of UHPFRC allow for the realization of very slender cross-sections with thin webs. For these beams, the shear capacity is the governing design issue. Hence, further investigations on the shear behavior with a variation of the fiber content, the prestressing level as well as the amount of shear reinforcement were undertaken. In this context, also size effects were examined using specimens with different construction heights up to 1.0 m. To enable testing of a high number of specimens with realistic cross-sectional dimensions and at reasonable effort, an innovative experimental setup was developed and used for the investigations. Apart from these laboratory tests the present article deals with the pilot application of a railway bridge made of UHPFRC in Germany. The design and construction process as well as measurement results of the load and deformation behavior of the prestressed precast bridge element are presented and discussed.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"1 2","pages":"41-53"},"PeriodicalIF":0.0,"publicationDate":"2019-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.201800005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75431542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Development and serviceability of a highway bridge deck using ultra-high performance fiber-reinforced concrete 超高性能纤维增强混凝土公路桥面的研制与使用性能

Civil Engineering Design Pub Date : 2019-03-23 DOI: 10.1002/cend.201900002

Takashi Kosaka, Yoshifumi Nishiumi, Toshimichi Ichinomiya, Kimio Saito

{"title":"Development and serviceability of a highway bridge deck using ultra-high performance fiber-reinforced concrete","authors":"Takashi Kosaka, Yoshifumi Nishiumi, Toshimichi Ichinomiya, Kimio Saito","doi":"10.1002/cend.201900002","DOIUrl":"https://doi.org/10.1002/cend.201900002","url":null,"abstract":"Lightweight orthotropic steel decks are widely used in urban expressways. However, fatigue cracks occur in the orthotropic steel deck. As a result, their maintenance cost has been increasing. Considering this problem, we have developed a deck slab using ultra-high performance fiber reinforced concrete (UHPFRC), as an alternative to the steel deck slab. The own weight of the UHPFRC deck slab is almost the same as that of an orthotropic steel deck slab. A UHPFRC deck has very thin components as compared with conventional concrete deck, thus the safety of the UHPFRC deck slab was analyzed via finite element analysis, and the fatigue durability of the UHPFRC deck slab was also confirmed via a wheel running fatigue test. The authors confirmed that the durability of the UHPFRC deck slab was sufficiently high and verified the serviceability of the deck using vibration and load tests. The characteristic frequency and impact coefficient of the deck were calculated, and the result indicated low possibility of resonance between the deck and cars.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"1 2","pages":"54-63"},"PeriodicalIF":0.0,"publicationDate":"2019-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.201900002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137977608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Experimental analysis of concrete elements under partial area strip loading 局部区域条形荷载作用下混凝土构件的试验分析

Civil Engineering Design Pub Date : 2019-03-18 DOI: 10.1002/cend.201900001

Gerald Schmidt-Thrö, Mario Smarslik, Bassem Tabka, Wolfgang Scheufler, Oliver Fischer, Peter Mark

{"title":"Experimental analysis of concrete elements under partial area strip loading","authors":"Gerald Schmidt-Thrö, Mario Smarslik, Bassem Tabka, Wolfgang Scheufler, Oliver Fischer, Peter Mark","doi":"10.1002/cend.201900001","DOIUrl":"10.1002/cend.201900001","url":null,"abstract":"Stresses for concrete elements under partial area strip loading are limited to 1.1-times the concrete compressive strength. In case of particularly small load application areas like at wall supports or segmental tunnel lining longitudinal joints this limitation may be governing the design. Additional load increases due to steel reinforcement confinement are not taken into account. This contribution presents various experimental series on large-scale reinforced concrete specimens conducted at the Technical University of Munich (TUM) and the Ruhr University Bochum (RUB). It is shown that splitting reinforcements with stiff anchorage (e.g. welded ladders) show distinct load-bearing capacity increases. Moreover, disregarding the demand for geometric affinity of load application and distribution areas facilitates a more precise estimation of load increase factors. Based upon the experiments and supplemental data from literature, practical design approaches are derived. They distinguish between high- and low-deformation capabilities of the rebar anchorage and—to the most extent—allow pronouncedly increased contact pressures compared to current design approaches.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"1 1","pages":"28-38"},"PeriodicalIF":0.0,"publicationDate":"2019-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.201900001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76915832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

First experiences with concrete screw anchors as postinstalled shear reinforcement in concrete bridges 混凝土螺钉锚作为混凝土桥梁后剪钢筋的首次经验

Civil Engineering Design Pub Date : 2019-03-18 DOI: 10.1002/cend.201800004

Johannes Lechner, Jürgen Feix

{"title":"First experiences with concrete screw anchors as postinstalled shear reinforcement in concrete bridges","authors":"Johannes Lechner, Jürgen Feix","doi":"10.1002/cend.201800004","DOIUrl":"10.1002/cend.201800004","url":null,"abstract":"Due to growing traffic volume and more restrictive design standards, structural engineers require new strengthening systems for concrete structures. Especially the level of calculated shear reinforcement has increased with the introduction of the Eurocode standards. Therefore, new methods to improve the shear strength of existing structures are needed. Concrete screws are used as a fastening system in concrete. Due to the mechanical connection, a very robust bond between the reinforcement element and the concrete is given. The new idea is to use these anchoring elements as postinstalled shear reinforcement. To show the usability and enhancements of the new method, several test series with concrete girders have been performed at the University of Innsbruck. Using concrete screws in several different configurations all test beams showed a remarkable increase in shear-load capacity. With a new design approach derived from the test results it was possible to apply the new system to several pilot-projects. One slab bridge built in the 1970s was strengthened to the load level according to Eurocode. Another pilot-project was realized at a railway bridge with a two span concrete box girder. This bridge was built with tendons vulnerable to stress corrosion cracking. To ensure a ductile failure, strengthening was necessary which was realized with concrete screws under ongoing traffic on and underneath the bridge. Currently a shear strengthening of a city tunnel in the central area of Munich is planned. In the roof slab about 7000 concrete screws are projected to be installed as shear and bending strengthening system.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"1 1","pages":"17-27"},"PeriodicalIF":0.0,"publicationDate":"2019-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.201800004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75051275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Material and space saving carbon concrete elements 节省材料和空间的碳混凝土元件

Civil Engineering Design Pub Date : 2019-03-14 DOI: 10.1002/cend.201800001

Egbert Müller, Silke Scheerer, Manfred Curbach

引用次数: 6

Comparison of different excitation- and data sampling-methods in structural health monitoring 结构健康监测中不同激励和数据采样方法的比较

Civil Engineering Design Pub Date : 2019-03-14 DOI: 10.1002/cend.201800002

Stefan Maas, Viet Ha Nguyen, Tanja Kebig, Sebastian Schommer, Arno Zürbes

{"title":"Comparison of different excitation- and data sampling-methods in structural health monitoring","authors":"Stefan Maas, Viet Ha Nguyen, Tanja Kebig, Sebastian Schommer, Arno Zürbes","doi":"10.1002/cend.201800002","DOIUrl":"10.1002/cend.201800002","url":null,"abstract":"Structural Health Monitoring with analysis of dynamic characteristics intends to detect stiffness changes caused by damage. It can be performed by vibrational tests resulting to modal parameters, that is, eigenfrequencies, damping, modeshapes, or modal masses. Those parameters are themselves informational and even allow often deducing the stiffness matrix. Based on that, it is possible to identify and to localize changes in the stiffness matrix due to damage, that is, localization and quantification of damage. However, changing test conditions, like ambient temperature or excitation force or existing nonlinearities of concrete, show important influence on damage indicators and hence need compensation prior to damage detection. Considering this background, this article focuses on comparing ambient excitation to forced excitation including appropriate exciters. Furthermore, continuous monitoring is discussed vs discrete testing in distinct time-intervals. The intention of the comparison is to give an overview, that is, helpful for choosing appropriate measurement technique for the sake of correct damage detection subsequently.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"1 1","pages":"10-16"},"PeriodicalIF":0.0,"publicationDate":"2019-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.201800002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86344475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1