Civil Engineering Design最新文献_第8页

Post-installed mechanical fasteners in high strength and ultra-high strength performance concrete 高、超高强度混凝土后安装机械紧固件

Civil Engineering Design Pub Date : 2019-10-21 DOI: 10.1002/cend.201900015

Michael Schwenn, Klaus Voit, Oliver Zeman, Konrad Bergmeister

{"title":"Post-installed mechanical fasteners in high strength and ultra-high strength performance concrete","authors":"Michael Schwenn, Klaus Voit, Oliver Zeman, Konrad Bergmeister","doi":"10.1002/cend.201900015","DOIUrl":"10.1002/cend.201900015","url":null,"abstract":"Post-installed fastening systems are essential in structural engineering nowadays. Triggered by the increasing popularity of high strength concrete (HSC) and ultra-high performance concrete (UHPC), fastening in these basements is more and more frequently applied. This inevitably leads to the question of the applicability of conventional fastening systems and the corresponding design concepts with concrete showing a compressive strength of up to 200 N/mm2. According to EAD 330232-00-0601, mechanical fasteners have to be placed in predrilled holes in compacted reinforced or unreinforced concrete without fibers with strength classes in the range of C20/25 to C50/60 in compliance with EN 206. This means that concrete strength class C50/60 also provides the reference for higher concrete strength; the impact of fibers and accompanying increase of concrete ductility is also excluded. Within the framework of this contribution it is intended to analyze the following aspects: (a) proof of applicability of various fastening systems in unreinforced and fiber-reinforced high strength concrete via experimental investigations and (b) making a statement regarding the currently valid European Assessment Document and provide experimental background for this issue.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"1 5-6","pages":"161-167"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.201900015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80624590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Calculation of risk costs in construction projects 建设项目风险成本的计算

Civil Engineering Design Pub Date : 2019-08-10 DOI: 10.1002/cend.201900014

Stefanie Brokbals, Vincent Wapelhorst, Ivan Čadež

{"title":"Calculation of risk costs in construction projects","authors":"Stefanie Brokbals, Vincent Wapelhorst, Ivan Čadež","doi":"10.1002/cend.201900014","DOIUrl":"10.1002/cend.201900014","url":null,"abstract":"As early as 1971, Schubert made a first contribution to the consideration of risks during the execution of construction projects. In addition to that, he was first to introduce elements of the risk management process to the construction management literature in Germany. By the use of an empirical study of the probability of risk occurrence and the cost amount by risk occurrence, Schubert made among others a statement about the importance of the risks depending on the amount of the risk costs. In an updated study for building construction projects with construction costs ≤2.5 million € and unit price contracts applying the VOB/B primarily the altered risk evaluations are shown; it needs to be emphasized that the sum of the determined risk costs corresponds to Schubert's results. Furthermore, with a variation of the characteristic attributes (response options) of the probability of risk occurrence and the cost amount by risk occurrence, it can be displayed that the risk costs during the execution of building construction projects are even considerably higher. Additionally, a probabilistic risk cost calculation — applying the Monte Carlo method — is used to reveal the bandwidth of risk costs. It can be pointed out that the risk costs range between 2.71% and 8.67% of the construction costs. The results could serve as a benchmark for contractors during the tender calculation to determine the amount of risk costs depending for example, on the market situation, the company-specific risk disposition as well as strategic considerations.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"1 3-4","pages":"120-128"},"PeriodicalIF":0.0,"publicationDate":"2019-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.201900014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85555944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Static and dynamic behavior of cellular glass products used for the bottom insulation of flat bottom tanks 用于平底罐底部绝缘的多孔玻璃制品的静态和动态性能

Civil Engineering Design Pub Date : 2019-08-05 DOI: 10.1002/cend.201800003

Till Waas, Robert Hertle, Marian Krol

引用次数: 0

Distributed fiber optic sensing for crack detection in concrete structures 分布式光纤传感在混凝土结构裂缝检测中的应用

Civil Engineering Design Pub Date : 2019-07-29 DOI: 10.1002/cend.201900008

Oliver Fischer, Sebastian Thoma, Simone Crepaz

引用次数: 35

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