Civil Engineering Design最新文献_第7页

Bond between concrete and rigid foam in precast concrete sandwich construction 预制混凝土夹层结构中混凝土与刚性泡沫的粘结

Civil Engineering Design Pub Date : 2020-11-24 DOI: 10.1002/cend.202000011

Kevin Metje, Torsten Leutbecher, Thorsten Weimar, Christian Hammer

{"title":"Bond between concrete and rigid foam in precast concrete sandwich construction","authors":"Kevin Metje, Torsten Leutbecher, Thorsten Weimar, Christian Hammer","doi":"10.1002/cend.202000011","DOIUrl":"10.1002/cend.202000011","url":null,"abstract":"In precast concrete sandwich construction mechanical connectors are used to transfer loads between the two concrete shells. Omitting these connectors seems economically interesting for realizing novel sandwich elements with lightweight facings made of textile-reinforced concrete or other materials. Then, the adhesion between the isolating layer and the cover layers becomes the decisive parameter. In order to evaluate the basic influence of surface texture and type of concrete on the bond strength, an experimental study including different rigid foams and ordinary performance concrete (OPC) as well as ultra-high performance concrete (UHPC) was carried out. The results of 120 tensile bond tests and 30 shear tests on concrete-rigid foam composites show that technically relevant bond strengths can be achieved by pouring the concrete onto the rigid foam. For OPC, the tensile bond strength is 50% higher than the minimum value required for external thermal insulation composite systems without mechanical connectors. For UHPC significantly higher bond strengths are obtained, which can be attributed to a better micromechanical interlock. In some cases, the strength of the composite was limited by the strength of the foam. The results are valuable for identifying promising rigid foam-concrete configurations.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"2 5-6","pages":"182-192"},"PeriodicalIF":0.0,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.202000011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"109989925","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: 2

Experimental analysis of the mechanical properties of concrete using alternative binding agents 不同粘结剂对混凝土力学性能的试验分析

Civil Engineering Design Pub Date : 2020-11-21 DOI: 10.1002/cend.201900017

Till Quadflieg, Nikita Morozov, Albina Karimova, Thomas Gries, Oleg Stolyarov

引用次数: 0

Feasibility of substitute building materials for circular use in urban green infrastructure 替代建筑材料在城市绿色基础设施循环使用的可行性

Civil Engineering Design Pub Date : 2020-11-20 DOI: 10.1002/cend.202000025

Petra Schneider, Sven Schwerdt, Katja Schulz, Sebastian Fiebig, Dominik Mirschel

{"title":"Feasibility of substitute building materials for circular use in urban green infrastructure","authors":"Petra Schneider, Sven Schwerdt, Katja Schulz, Sebastian Fiebig, Dominik Mirschel","doi":"10.1002/cend.202000025","DOIUrl":"10.1002/cend.202000025","url":null,"abstract":"Mineral waste, including non-hazardous construction waste, is the largest waste stream once a country has reached a certain degree of urbanization. This waste stream has a significant potential to replace primary raw materials. Although a large part of the construction waste is reused, other mineral materials such as ashes or slags have only been used for backfilling or are deposited in landfills. The aim of the investigations is to determine the usability of substitute building materials (SBM) in higher-quality applications, particularly in urban green infrastructure, for example, Reinforced Soil Structures (RSS) or Green Roofs (GR). In addition to technical and environmental requirements, the greening of the material is relevant. The study concept includes soil mechanical laboratory tests as well as greening tests on SBM, namely slags, ashes, residue sands, and crushed/milled brick. The lab results illustrate the feasibility and applicability conditions for the investigated SBM. Upscaling the lab test results, in the next step the construction of a RSS with complete substitution of the primary building materials is started as large scale pilot test.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"2 5-6","pages":"159-168"},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.202000025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"99894354","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: 4

Experimental characterization of bond fatigue of carbon reinforced concrete 碳增强混凝土粘结疲劳试验研究

Civil Engineering Design Pub Date : 2020-11-03 DOI: 10.1002/cend.202000019

Juliane Wagner, Manfred Curbach

引用次数: 1

Reinforcement strategies for 3D-concrete-printing 3d混凝土打印的加固策略

Civil Engineering Design Pub Date : 2020-09-04 DOI: 10.1002/cend.202000022

Harald Kloft, Martin Empelmann, Norman Hack, Eric Herrmann, Dirk Lowke

{"title":"Reinforcement strategies for 3D-concrete-printing","authors":"Harald Kloft, Martin Empelmann, Norman Hack, Eric Herrmann, Dirk Lowke","doi":"10.1002/cend.202000022","DOIUrl":"10.1002/cend.202000022","url":null,"abstract":"The ingenious bridge, roof, and shell structures of the last century were designed from the understanding of the congenial interaction of the two materials concrete and steel. Nowadays, reinforced concrete is the most widely used material in construction. The use of system formwork and easy-to-install reinforcement support structures that are optimized in terms of labor costs, but often have inefficient use of material. In this context, Stefan Polónyi has repeatedly criticized the engineers' lost understanding of the interaction of concrete and reinforcement. With Additive Manufacturing, an innovative digital manufacturing technology is now available that allows new freedom in concrete design with a resource-efficient use of materials at the same time. With regard to practical application, the integration of reinforcement represents a central challenge in 3D-concrete-printing. The authors see here the future chance of a force-flow controlled reinforcement layout. The paper shows new strategies for the combined Additive Manufacturing of concrete and reinforcement and presents first 3D-printed reinforced concrete elements.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"2 4","pages":"131-139"},"PeriodicalIF":0.0,"publicationDate":"2020-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.202000022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113168402","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: 22

Design of modular concrete heliostats using symmetry reduction methods 采用对称约简法设计模块化混凝土定日镜

Civil Engineering Design Pub Date : 2020-08-12 DOI: 10.1002/cend.202000013

Patrick Forman, Sebastian Penkert, Peter Mark, Jürgen Schnell

{"title":"Design of modular concrete heliostats using symmetry reduction methods","authors":"Patrick Forman, Sebastian Penkert, Peter Mark, Jürgen Schnell","doi":"10.1002/cend.202000013","DOIUrl":"10.1002/cend.202000013","url":null,"abstract":"In Concentrated Solar Power (CSP) plants the incident solar radiation is focused onto a receiver by means of collectors. A fluid is heated up and in a downstream power block electricity is generated. In point-focusing solar towers, the solar concentration is achieved by so-called heliostats that are arranged to a solar field. In this contribution, the development of concrete heliostats with circular shapes and an aperture area of 30 m2 is presented. A high-performance concrete with high tensile and compressive strength values is used. The circular structure is dissolved into identical but symmetrically reduced modules derived from system reduction methods. For designing, the tensile strength of the concrete is restrictive to ensure linear-elastic material behavior and to avoid softening by cracking. After dimensioning, the derived equivalent plate is converted into strut-like structures possessing equal stiffnesses with respect to the partial module size. These modules are circularly post-tensioned to form a heliostat. Numerical investigations of the modules prove their accuracy. A full solar concentration, that is, the reflected solar radiation is completely focused on the receiver, is achieved. Due to the multitude of modules within a solar field, serial production with integrated quality control is recommended.","PeriodicalId":100248,"journal":{"name":"Civil Engineering Design","volume":"2 4","pages":"92-103"},"PeriodicalIF":0.0,"publicationDate":"2020-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cend.202000013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74428029","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: 8

The crack propagation velocity as a reason for the strain rate effect of concrete: An analytical model 裂缝扩展速度作为混凝土应变率效应的原因:一个解析模型

Civil Engineering Design Pub Date : 2020-08-12 DOI: 10.1002/cend.202000018

Oliver Mosig, Manfred Curbach

引用次数: 6

Planar tomography and numerical analysis for damage characterization of impact loaded RC plates 冲击载荷RC板损伤表征的平面层析成像与数值分析

Civil Engineering Design Pub Date : 2020-08-12 DOI: 10.1002/cend.202000017

Deborah Nerger, Robabeh Moosavi, Franz Bracklow, Marcus Hering, Tino Kühn, Manfred Curbach, Falk Hille, Andreas Rogge

引用次数: 4

Loop-shaped elements for anchoring carbon reinforcement in concrete 混凝土中碳钢筋锚固用环形元件

Civil Engineering Design Pub Date : 2020-08-12 DOI: 10.1002/cend.202000014

Kerstin Speck, Steffen Rittner, Franz Bracklow, Mateusz Ewertowski, Manfred Curbach, Chokri Cherif