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  Subjects -> ENGINEERING (Total: 2266 journals)
    - CHEMICAL ENGINEERING (190 journals)
    - CIVIL ENGINEERING (181 journals)
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    - ENGINEERING (1197 journals)
    - ENGINEERING MECHANICS AND MATERIALS (390 journals)
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CIVIL ENGINEERING (181 journals)                     

Showing 1 - 0 of 0 Journals sorted alphabetically
ACI Structural Journal     Full-text available via subscription   (Followers: 16)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 1)
Acta Structilia : Journal for the Physical and Development Sciences     Open Access   (Followers: 2)
Advances in Civil Engineering     Open Access   (Followers: 32)
Advances in Structural Engineering     Full-text available via subscription   (Followers: 26)
Ambiente Construído     Open Access   (Followers: 1)
American Journal of Civil Engineering and Architecture     Open Access   (Followers: 28)
Architectural Engineering     Open Access   (Followers: 4)
Archives of Civil and Mechanical Engineering     Full-text available via subscription  
Archives of Civil Engineering     Open Access   (Followers: 9)
Archives of Hydro-Engineering and Environmental Mechanics     Open Access   (Followers: 1)
ATBU Journal of Environmental Technology     Open Access   (Followers: 3)
Australian Journal of Structural Engineering     Full-text available via subscription   (Followers: 6)
Baltic Journal of Road and Bridge Engineering     Full-text available via subscription   (Followers: 1)
BER : Building and Construction : Full Survey     Full-text available via subscription   (Followers: 8)
BER : Building Contractors' Survey     Full-text available via subscription   (Followers: 4)
BER : Building Sub-Contractors' Survey     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Building and Construction : An Executive Summary     Full-text available via subscription   (Followers: 4)
Berkeley Planning Journal     Open Access   (Followers: 7)
Bioinspired Materials     Open Access   (Followers: 3)
Bridge Structures : Assessment, Design and Construction     Hybrid Journal   (Followers: 15)
Building and Environment     Hybrid Journal   (Followers: 15)
Building Women     Full-text available via subscription  
Built Environment Project and Asset Management     Hybrid Journal   (Followers: 15)
Bulletin of Pridniprovsk State Academy of Civil Engineering and Architecture     Open Access   (Followers: 5)
Canadian Journal of Civil Engineering     Full-text available via subscription   (Followers: 10)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 7)
Case Studies in Nondestructive Testing and Evaluation     Open Access   (Followers: 8)
Case Studies in Structural Engineering     Open Access   (Followers: 8)
Cement and Concrete Composites     Hybrid Journal   (Followers: 16)
Challenge Journal of Concrete Research Letters     Open Access   (Followers: 1)
Challenge Journal of Structural Mechanics     Open Access   (Followers: 4)
Change Over Time     Full-text available via subscription   (Followers: 2)
Civil and Environmental Engineering     Open Access   (Followers: 7)
Civil And Environmental Engineering Reports     Open Access   (Followers: 4)
Civil and Environmental Research     Open Access   (Followers: 17)
Civil Engineering = Siviele Ingenieurswese     Full-text available via subscription   (Followers: 4)
Civil Engineering and Architecture     Open Access   (Followers: 16)
Civil Engineering and Environmental Systems     Hybrid Journal   (Followers: 2)
Civil Engineering and Technology     Open Access   (Followers: 8)
Civil Engineering Dimension     Open Access   (Followers: 7)
Cohesion and Structure     Full-text available via subscription   (Followers: 2)
Composite Structures     Hybrid Journal   (Followers: 240)
Computer-aided Civil and Infrastructure Engineering     Hybrid Journal   (Followers: 10)
Computers & Structures     Hybrid Journal   (Followers: 31)
Concrete Research Letters     Open Access   (Followers: 5)
Construction Economics and Building     Open Access   (Followers: 2)
Construction Engineering     Open Access   (Followers: 8)
Construction Management and Economics     Hybrid Journal   (Followers: 20)
Construction Science     Open Access   (Followers: 4)
Constructive Approximation     Hybrid Journal  
Curved and Layered Structures     Open Access   (Followers: 1)
DFI Journal : The Journal of the Deep Foundations Institute     Hybrid Journal   (Followers: 1)
Earthquake Engineering and Structural Dynamics     Hybrid Journal   (Followers: 16)
Enfoque UTE     Open Access   (Followers: 3)
Engineering Project Organization Journal     Hybrid Journal   (Followers: 6)
Engineering Structures     Hybrid Journal   (Followers: 12)
Engineering Structures and Technologies     Hybrid Journal   (Followers: 1)
Engineering, Construction and Architectural Management     Hybrid Journal   (Followers: 13)
Environmental Geotechnics     Hybrid Journal   (Followers: 4)
European Journal of Environmental and Civil Engineering     Hybrid Journal   (Followers: 6)
Fatigue & Fracture of Engineering Materials and Structures     Hybrid Journal   (Followers: 14)
Frattura ed Integrità Strutturale : Fracture and Structural Integrity     Open Access  
Frontiers in Built Environment     Open Access  
Frontiers of Structural and Civil Engineering     Hybrid Journal   (Followers: 6)
Geomaterials     Open Access   (Followers: 3)
Geosystem Engineering     Hybrid Journal   (Followers: 1)
Geotechnik     Hybrid Journal   (Followers: 2)
Géotechnique Letters     Hybrid Journal   (Followers: 6)
HBRC Journal     Open Access   (Followers: 1)
Hormigón y Acero     Full-text available via subscription  
HVAC&R Research     Hybrid Journal  
Indoor and Built Environment     Hybrid Journal   (Followers: 2)
Infrastructure Asset Management     Hybrid Journal   (Followers: 1)
Insight - Non-Destructive Testing and Condition Monitoring     Full-text available via subscription   (Followers: 18)
International Journal for Service Learning in Engineering     Open Access  
International Journal of 3-D Information Modeling     Full-text available via subscription   (Followers: 3)
International Journal of Advanced Structural Engineering     Open Access   (Followers: 14)
International Journal of Concrete Structures and Materials     Open Access   (Followers: 11)
International Journal of Condition Monitoring     Full-text available via subscription   (Followers: 2)
International Journal of Construction Engineering and Management     Open Access   (Followers: 8)
International Journal of Geo-Engineering     Open Access   (Followers: 1)
International Journal of Geosynthetics and Ground Engineering     Full-text available via subscription   (Followers: 3)
International Journal of Masonry Research and Innovation     Hybrid Journal   (Followers: 1)
International Journal of Pavement Research and Technology     Open Access   (Followers: 3)
International Journal of Protective Structures     Hybrid Journal   (Followers: 5)
International Journal of Steel Structures     Hybrid Journal   (Followers: 2)
International Journal of Structural Engineering     Hybrid Journal   (Followers: 10)
International Journal of Structural Integrity     Hybrid Journal   (Followers: 2)
International Journal of Structural Stability and Dynamics     Hybrid Journal   (Followers: 6)
International Journal of Sustainable Built Environment     Open Access   (Followers: 4)
International Journal of Sustainable Construction Engineering and Technology     Open Access   (Followers: 8)
International Journal on Pavement Engineering & Asphalt Technology     Open Access   (Followers: 6)
International Journal Sustainable Construction & Design     Open Access  
Journal of Bridge Engineering     Full-text available via subscription   (Followers: 15)
Journal of Building Engineering     Hybrid Journal   (Followers: 1)
Journal of Building Materials and Structures     Open Access   (Followers: 2)
Journal of Building Performance Simulation     Hybrid Journal   (Followers: 6)
Journal of Civil Engineering and Construction Technology     Open Access   (Followers: 10)
Journal of Civil Engineering and Management     Hybrid Journal   (Followers: 7)
Journal of Civil Engineering and Science     Open Access   (Followers: 7)
Journal of Civil Engineering Research     Open Access   (Followers: 6)
Journal of Civil Society     Hybrid Journal   (Followers: 3)
Journal of Civil Structural Health Monitoring     Hybrid Journal   (Followers: 4)
Journal of Composites     Open Access   (Followers: 79)
Journal of Composites for Construction     Full-text available via subscription   (Followers: 13)
Journal of Computing in Civil Engineering     Full-text available via subscription   (Followers: 24)
Journal of Construction Engineering     Open Access   (Followers: 7)
Journal of Construction Engineering and Management     Full-text available via subscription   (Followers: 19)
Journal of Construction Engineering, Technology & Management     Full-text available via subscription   (Followers: 2)
Journal of Constructional Steel Research     Hybrid Journal   (Followers: 8)
Journal of Earth Sciences and Geotechnical Engineering     Open Access   (Followers: 3)
Journal of Fluids and Structures     Hybrid Journal   (Followers: 6)
Journal of Frontiers in Construction Engineering     Open Access   (Followers: 2)
Journal of Green Building     Full-text available via subscription   (Followers: 11)
Journal of Highway and Transportation Research and Development (English Edition)     Full-text available via subscription   (Followers: 12)
Journal of Infrastructure Systems     Full-text available via subscription   (Followers: 20)
Journal of Legal Affairs and Dispute Resolution in Engineering and Construction     Full-text available via subscription   (Followers: 5)
Journal of Marine Science and Engineering     Open Access   (Followers: 1)
Journal of Materials in Civil Engineering     Full-text available via subscription   (Followers: 10)
Journal of Multifunctional Composites     Full-text available via subscription   (Followers: 4)
Journal of Nondestructive Evaluation     Hybrid Journal   (Followers: 9)
Journal of Offshore Structure and Technology     Full-text available via subscription  
Journal of Performance of Constructed Facilities     Full-text available via subscription   (Followers: 4)
Journal of Pipeline Systems Engineering and Practice     Full-text available via subscription   (Followers: 7)
Journal of Rehabilitation in Civil Engineering     Open Access   (Followers: 1)
Journal of Solid Waste Technology and Management     Full-text available via subscription  
Journal of Structural Engineering     Full-text available via subscription   (Followers: 38)
Journal of Structural Fire Engineering     Full-text available via subscription   (Followers: 6)
Journal of Sustainable Architecture and Civil Engineering     Open Access   (Followers: 3)
Journal of Sustainable Design and Applied Research in Innovative Engineering of the Built Environment     Open Access   (Followers: 1)
Journal of the South African Institution of Civil Engineering     Open Access   (Followers: 4)
Jurnal Teknik Sipil dan Perencanaan     Open Access  
KSCE Journal of Civil Engineering     Hybrid Journal   (Followers: 1)
Latin American Journal of Solids and Structures     Open Access   (Followers: 1)
Materiales de Construcción     Open Access  
Mathematical Modelling in Civil Engineering     Open Access   (Followers: 3)
Nondestructive Testing And Evaluation     Hybrid Journal   (Followers: 15)
Obras y Proyectos     Open Access   (Followers: 1)
Open Journal of Civil Engineering     Open Access   (Followers: 6)
Photonics and Nanostructures - Fundamentals and Applications     Hybrid Journal   (Followers: 3)
Practice Periodical on Structural Design and Construction     Full-text available via subscription   (Followers: 4)
Proceedings of the Institution of Civil Engineers - Bridge Engineering     Hybrid Journal   (Followers: 7)
Proceedings of the Institution of Civil Engineers - Civil Engineering     Hybrid Journal   (Followers: 11)
Proceedings of the Institution of Civil Engineers - Management, Procurement and Law     Hybrid Journal   (Followers: 7)
Proceedings of the Institution of Civil Engineers - Municipal Engineer     Hybrid Journal   (Followers: 3)
Proceedings of the Institution of Civil Engineers - Structures and Buildings     Hybrid Journal   (Followers: 4)
Random Structures and Algorithms     Hybrid Journal   (Followers: 4)
Recent Trends In Civil Engineering & Technology     Full-text available via subscription   (Followers: 4)
Research in Nondestructive Evaluation     Hybrid Journal   (Followers: 5)
Revista IBRACON de Estruturas e Materiais     Open Access   (Followers: 1)
Road Materials and Pavement Design     Hybrid Journal   (Followers: 9)
Russian Journal of Nondestructive Testing     Hybrid Journal   (Followers: 4)
Science and Engineering of Composite Materials     Hybrid Journal   (Followers: 60)
Selected Scientific Papers - Journal of Civil Engineering     Open Access   (Followers: 3)
Slovak Journal of Civil Engineering     Open Access   (Followers: 2)
Soils and foundations     Full-text available via subscription   (Followers: 3)
Steel Construction - Design and Research     Hybrid Journal   (Followers: 3)
Structural and Multidisciplinary Optimization     Hybrid Journal   (Followers: 9)
Structural Concrete     Hybrid Journal   (Followers: 10)
Structural Control and Health Monitoring     Hybrid Journal   (Followers: 7)
Structural Engineering International     Full-text available via subscription   (Followers: 11)
Structural Safety     Hybrid Journal   (Followers: 7)
Structural Survey     Hybrid Journal  
Structure     Full-text available via subscription   (Followers: 25)
Structure and Infrastructure Engineering: Maintenance, Management, Life-Cycle Design and Performance     Hybrid Journal   (Followers: 12)
Structures     Hybrid Journal   (Followers: 1)
Study of Civil Engineering and Architecture     Open Access   (Followers: 8)
Superlattices and Microstructures     Hybrid Journal   (Followers: 2)
Surface Innovations     Hybrid Journal  
Technical Report Civil and Architectural Engineering     Open Access  
Teknik     Open Access  
The IES Journal Part A: Civil & Structural Engineering     Hybrid Journal   (Followers: 6)
The Structural Design of Tall and Special Buildings     Hybrid Journal   (Followers: 6)
Thin Films and Nanostructures     Full-text available via subscription   (Followers: 2)
Thin-Walled Structures     Hybrid Journal   (Followers: 4)
Transactions of the VŠB - Technical University of Ostrava. Construction Series     Open Access   (Followers: 1)
Transportation Geotechnics     Full-text available via subscription   (Followers: 1)
Transportation Infrastructure Geotechnology     Hybrid Journal   (Followers: 8)
Water Science & Technology     Partially Free   (Followers: 25)
Water Science and Technology : Water Supply     Partially Free   (Followers: 22)

           

Journal Cover Structural Concrete
  [SJR: 0.874]   [H-I: 14]   [10 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1464-4177 - ISSN (Online) 1751-7648
   Published by John Wiley and Sons Homepage  [1616 journals]
  • Design optimization to increase the (buckling) stability of concrete
           columns
    • Authors: Angela Schmidt; Manfred Curbach
      Abstract: In 2014 and 2015, concrete columns were tested under axial compression in the Otto-Mohr-Laboratory of Dresden University of Technology. In comparison to columns with the same volume and a constant rectangular cross section, a 25% increase in buckling resistance was attained with an optimized shape. The shape of a column can be optimized in both the longitudinal and the transverse direction. Both aforementioned possibilities were tested separately in two experimental series; the results of such tests were used to verify the accuracy of the theoretical calculations. Based on these calculations and considerations, it was determined that an even larger increase of the buckling load is possible, for example, by combining both form influences (cross section and shape in longitudinal direction). A literature review regarding the optimization of axially loaded columns was conducted in 2012 and 2013. First, the current study gives an overview of the mathematical results. Subsequently, it presents the column test results in detail. Both simply supported columns and columns with fixed ends were tested. All columns were designed with ultra-high-performance concrete. The outcomes of the experiments are provided and discussed. Additionally, the measured values are compared with the calculated values.
      PubDate: 2017-03-23T19:50:39.542979-05:
      DOI: 10.1002/suco.201600183
       
  • Cover Picture: Structural Concrete 1/2017
    • PubDate: 2017-03-22T18:06:44.426685-05:
      DOI: 10.1002/suco.1090
       
  • Expansion behavior of a biaxially reinforced concrete member affected by
           alkali-silica reaction
    • Authors: David Wald; Gloriana Arrieta Martinez, Oguzhan Bayrak
      Abstract: The development and multiaxial distribution of mechanical expansions caused by alkali-silica reaction were quantified for a large-scale reinforced concrete beam containing top and bottom mats of bidirectional reinforcement with no reinforcement through its depth. The effects of different conditioning environments and the influence of reinforcing bar size and layout on the expansion behavior of the beam were also considered. Expansions in the unreinforced direction exceeded those in the reinforced directions at all times. Expansions in the reinforced directions stopped prior to steel yielding and before concrete finished expanding in the unreinforced direction. Expansion behavior in biaxially reinforced beam regions was not influenced by triaxial restraint conditions at adjacent beam ends. Varying moisture exposure conditions along the length affected the time development of expansions but not the distribution of given volumetric expansions among primary directions.
      PubDate: 2017-03-21T19:01:33.40683-05:0
      DOI: 10.1002/suco.201600143
       
  • Proof load testing of reinforced concrete slab bridges in the Netherlands
    • Authors: Eva Lantsoght; Cor Veen, Ane Boer, Dick A. Hordijk
      Abstract: The bridges built during the development of the Dutch road network after the Second World War are reaching their originally devised service life. A large subset of the Dutch bridge stock consists of reinforced concrete slab bridges. This bridge type often rates insufficient according to the recently introduced Eurocodes. Therefore, more suitable methods are developed to assess reinforced concrete slab bridges to help transportation officials make informed decisions about the safety and remaining life of the existing bridges. Field testing can be used for example when the effect of deterioration on the structural capacity is unknown. A proof load test demonstrates that a given bridge can carry a certain load level. In the Netherlands, a number of existing reinforced concrete slab bridges have been proof loaded, and one bridge has been tested to collapse. Bridges with and without material damage were tested. These bridges were heavily instrumented, in order to closely monitor the behavior of the bridge. Critical positions for bending moment and shear were studied. Based on the proof load tests that were carried out over the past years, a set of recommendations for the systematic preparation, execution, and analysis of proof load test results is compiled. These recommendations will ultimately form the basis of the guideline for proof load testing for the Netherlands, which is currently under development.
      PubDate: 2017-03-21T18:51:44.752525-05:
      DOI: 10.1002/suco.201600171
       
  • A model for the simultaneous prediction of the flexural and shear
           deflections of statically determinate and indeterminate reinforced
           concrete structures
    • Authors: Honeyeh Ramezansefat; Joaquim Barros, Mohammadali Rezazadeh
      Abstract: The deformability of the major part of reinforced concrete (RC) structures is the result of the flexural and shear deformations mainly caused by bending and shear diagonal cracking, respectively. However, the evaluation of the shear deformation contribution is relatively difficult due to the complexities involving the shear behavior of cracked RC elements. These complexities are even more complicated when structures are statically indeterminate, since the external and internal forces cannot be determined from direct application of the equilibrium equations. To address these issues, this study aims to develop a novel simplified analytical model based on the flexibility (force) method to predict the deflections of statically indeterminate RC structures up to their failure, which can be in bending or in shear. This analytical model considers the influence of flexural cracks on the shear stiffness degradation of an RC structure after concrete cracking initiation, and has a format adjusted for design practice. The good predictive performance of the analytical model is demonstrated by simulating experimental tests with RC elements where shear deformation has different level of contribution for the total deflection registered in these tests.
      PubDate: 2017-03-19T19:41:29.944213-05:
      DOI: 10.1002/suco.201600116
       
  • Basic parameters test and 3D modeling of bond between high-strength
           concrete and ribbed steel bar after elevated temperatures
    • Authors: Weiping Zhao; Binrong Zhu
      Abstract: This paper presents basic parameters test and an efficient numerical model for the bond between reinforcing bars and concrete after elevated temperatures. The chemical adhesive and friction coefficient are measured by self-designed setups, and the variation law of the parameters is summarized. In the 3D modeling, bar-to-concrete interface has been modeled by means of an explicit discretization of the bar ribs. Surface-to-surface contact pair elements are employed for the interface, and the tangential contact behavior is elastic-plastic with a Coulomb-type friction model. Comparison between experimental and numerical results shows that the proposed model describes the behavior of steel bar relatively well in the pull-out process after elevated temperatures. The 3D modeling makes up some deficiencies of macro pull-out test, such as the detailed stress distributions and crack patterns.
      PubDate: 2017-03-16T22:41:10.967361-05:
      DOI: 10.1002/suco.201600005
       
  • Strengthening corbels using post-installed threaded rods
    • Authors: Tadeusz Urban; Łukasz Krawczyk
      Abstract: The paper presents the results of experimental research into the use of post-installed threaded rods as additional reinforcement. An increase in load-carrying capacity of up to 64% was obtained for strengthened corbels compared with unstrengthened corbels (reference corbels). Calculations were performed of the load-carrying capacity of corbels using a model developed on the basis of the literature and the obtained results were compared with results calculated according to the EN-1992-1-1. Strain diagrams for primary reinforcement, stirrups, and the compressed surface of concrete are presented, alongside with a description of the development of cracking and photographs of the corbels after failure. In the second section, publications about the calculation of the load-carrying capacity of corbels and on different reinforcement methods are quoted.
      PubDate: 2017-03-16T17:59:07.293645-05:
      DOI: 10.1002/suco.201600215
       
  • Deformation analysis of reinforced concrete ties: Representative geometry
    • Authors: Viktor Gribniak; Arvydas Rimkus, Lluis Torres, Ruta Jakstaite
      Abstract: Regardless of the simplicity of the test layout, interpretation of the tensile test results may be inadequate. Typically, a test of the reinforced concrete tie provides measurements of average deformations of the internal reinforcing bar and the concrete surface. The experimental evidence, however, often contradicts with the general assumption of the similarity of mean strains of the reinforcement and concrete. Analysis of the sources influencing the scatter of the experimental results motivated this investigation of the representativeness of the specimens. In this study, the representativeness is understood as a property of a tie to isolate the investigated parameters (e.g., the deformation components) from other uncontrolled effects typical of test with limited sample sizes. This study aims at determining the representative geometry of the test samples that would enable the reduction of the end effect. A consistent procedure is proposed for identifying the cracking parameters of the ties with different testing layouts.
      PubDate: 2017-03-16T17:58:51.834039-05:
      DOI: 10.1002/suco.201600105
       
  • Alkali–silica reaction in concrete structures due to simultaneous cyclic
           loading and external supply of alkali: Results of the DFG research group
           FOR 1498
    • Authors: Rolf Breitenbücher
      PubDate: 2017-03-13T19:35:31.357551-05:
      DOI: 10.1002/suco.201600178
       
  • Application of geopolymer paste for concrete repair
    • Authors: Yung-Chin Ding; Ta-Wui Cheng, Yu-Sheng Dai
      Abstract: In this study, ground granulated blast furnace slag and coal fly ash were used as raw materials to prepare geopolymer paste as repair material for concrete structure. The functional properties, such as compressive strength, fluxural strength, and bonding strength between slag/fly ash based geopolymer paste and paste substrate were investigated. The SiO2/Na2O molar ratio of the alkali activator plays an important role on the strength of geopolymer paste. The nature of the geopolymeric reaction product was examined using FTIR and NMR. The compressive strengths and flexural strength of the geopolymer paste were 47 MPa and 16 MPa, respectively. For concrete substrate bonded with geopolymer paste, the compressive strength test shows up to 120% repairing rate can be achieved. By comparing with Portland cement, it can be proved that the slag/fly ash based geopolymer paste has very good potential for further engineering development in the future.
      PubDate: 2017-03-10T11:03:51.873572-05:
      DOI: 10.1002/suco.201600161
       
  • Moment–curvature response of engineered cementitious composites
           under cyclic loading
    • Authors: Wei Zhang; Jia-Bao Yan
      Abstract: The research presented herein describes the testing performed to examine the potential use of engineered cementitious composite (ECC) materials in lieu of traditional materials. Laboratory studies were used to examine the response of ECC materials under cyclic loading. The cyclic testing results indicated that ECC materials have a unique response to cyclic loading; the stiffness of ECC varies with the applied tensile strain and loading history. According to the cyclic response from the moment–curvature relation using cross-sectional analysis, a stress–strain model was proposed to simulate the cyclic response of ECC; the model showed good agreement with the experimental results.
      PubDate: 2017-03-10T10:33:22.830013-05:
      DOI: 10.1002/suco.201600113
       
  • Bond of deformed steel reinforcement in lightweight foamed concrete
    • Authors: Johannes P. de Villiers; Gideon P.A.G. van Zijl, Algurnon S. van Rooyen
      Abstract: Low weight and thermal insulating properties make lightweight foamed concrete (LWFC) an attractive substitute for normal-weight concrete (NWC). The unfamiliarity and paucity of design guidance challenge the structural use of LWFC. One concern is the bond of steel reinforcement in LWFC. This paper presents the results of pull-out bond tests and beam-end bond tests. The parameters were a reference NWC and LWFC with densities of 1,200, 1,400, and 1,600 kg/m3 and rebar diameters of 10, 12, and 20 mm with embedded lengths of 3, 4, and 5 bar diameters. All concretes were characterized in terms of strength, stiffness, and fracture energy. Clear differences in bond resistance were found from the two tests. The bond in LWFC is lower than that in NWC. The results suggest that the development of LWFC materials to increase fracture energy has the potential to increase the bond.
      PubDate: 2017-03-07T03:30:40.613844-05:
      DOI: 10.1002/suco.201600019
       
  • Progressive collapse assessment of medium-rise reinforced concrete flat
           slab structures
    • Authors: Fatma Attia; Hamed Salem, Nabil Yehia
      Abstract: The progressive collapse resistance of a medium-rise multistory reinforced concrete flat slab structure is evaluated numerically using the applied element method. The case study is designed according to ACI 318 and its progressive collapse is assessed in accordance with the Unified Facilities Criteria (UFC) guidelines. The numerical results show that the case study considered generally satisfies the limits of the UFC guidelines except for the case of near-corner interior column loss at the 10th floor and edge shear wall loss at ground, 5th, 8th, and 10th floors. The removal of the edge shear walls on the higher floors caused a partial collapse.
      PubDate: 2017-03-03T08:40:56.966357-05:
      DOI: 10.1002/suco.201600051
       
  • Cyclic loading test for columns made with ultra-strength fiber-reinforced
           concrete and trace analyses using finite element analyses
    • Authors: Tadaaki Nozawa; Joon-Ho Choi, Masahiro Hattori, Hisanori Otsuka
      Abstract: First, cyclic loading tests were conducted on scaled-down bridge column models using normal- and ultra-strength fiber-reinforced concrete made with polyvinyl alcohol fibers (PVA-UFC) and normal- and ultrahigh-strength rebars. The experimental results were compared, focusing on the relation between load and displacement, skeleton, crack distribution, and failure modes. Second, in order to evaluate the reproducibility of the cyclic loading test by finite element (FE) analysis, trace analyses were carried out. The FE analyses investigated the applicability of the conventional analytical model of concrete for PVA-UFC. Compared with the experimental results, overall hysteresis loops and maximum strength responses were reproduced with sufficient accuracy by using adequate analytical models. Lastly, parametric analyses were conducted on varying cross-sectional areas of columns, and the extent to which cross-sectional areas could be reduced by using UFC was investigated.
      PubDate: 2017-03-02T03:25:48.682111-05:
      DOI: 10.1002/suco.201600053
       
  • Reliability-based approach to the robustness of corroded reinforced
           concrete structures
    • Authors: Eduardo S. Cavaco; Luis A.C. Neves, Joan R. Casas
      Abstract: Currently, decisions on the maintenance and repair of infrastructural assets, structures in particular, are mostly based on the results of inspections and the resulting condition index, neglecting system robustness and therefore not making optimal use of the limited funds available. This paper presents a definition and a measure of structural robustness in the context of deteriorating structures which are compatible with asset management systems for optimal maintenance and repair planning. The proposed index is used to define the robustness of existing reinforced concrete (RC) structures to rebar corrosion. Structural performance and the corresponding reliability index are assessed using combined advanced reliability and structural analysis techniques. Structural analysis explicitly includes deterioration mechanisms resulting from corrosion, such as reinforcement area reduction, concrete cracking, and bond deterioration. The first-order reliability method, combined with a response surface algorithm, is used to compute the reliability index for a wide range of different corrosion levels, resulting in a fragility curve. Finally, structural robustness is computed and discussed based on the results obtained. A robustness comparison of different structures can then be used to determine structural types more tolerant to corrosion and these results used for planning maintenance and repairs.
      PubDate: 2017-02-27T18:15:29.044273-05:
      DOI: 10.1002/suco.201600084
       
  • Displacement-based finite layer element analysis on rotational behavior of
           reinforced concrete beam segments containing hinges
    • Authors: Binbin Zhou; Ruoyang Wu, Jian Feng
      Abstract: Rotation capacity of reinforced concrete (RC) beams is a vital property for its relationships with moment redistribution, energy absorbability, and so on. Evaluation of the rotation capacity has been one of the classic and intractable problems in structural engineering over the past decades. The precise prediction about rotational behavior of a RC beam is the primary basis of quantifying its rotation capacity. In this paper a displacement-based finite layer element method considering the factors of flexural cracks, concrete crushing, and pre-and postyield behavior of bond is presented to predict the rotational behavior. In conclusion, it shows good agreement between simulation results, implemented by the proposed method, and the test results in the literature.
      PubDate: 2017-02-27T18:10:47.127383-05:
      DOI: 10.1002/suco.201600100
       
  • Shear capacity of steel fiber-reinforced concrete beams
    • Authors: Deuck Hang Lee; Sun-Jin Han, Kang Su Kim, James M. LaFave
      Abstract: This study proposes a shear strength model for steel fiber-reinforced concrete (SFRC) beams—the so-called dual potential capacity model (DPCM). It can suitably consider the dominant shear failure mode, including the shear contributions of the compression side and the cracked tension side, at the section considered. In the proposed approach, the direct tension force transfer model (DTFTM), which can consider the random orientation and bond characteristics of steel fibers at a crack surface, has been introduced to calculate the shear contribution of the steel fibers. Shear test results of SFRC beams have been collected from various references and compared with the analysis results of the proposed DPCM. A simplified version of the DPCM was also developed for practical applications by reducing the iterative computational procedures.
      PubDate: 2017-02-26T19:35:42.56358-05:0
      DOI: 10.1002/suco.201600104
       
  • Numerical study of reinforced and prestressed concrete components under
           biaxial tensile stresses
    • Authors: Robert Zobel; Manfred Curbach
      Abstract: The focus of this study was the numerical investigation of reinforced and prestressed concrete components under biaxial tensile stresses in ANSYS in order to display the state of stress in a containment wall. Solid elements were used for concrete, whereas beam elements were used for reinforcing steel. The description and representation of the nonlinear material behavior and the fundamental phenomena of the damage of the concrete was implemented by using an elastoplastic material model. As crack width, crack spacing, and the deformation behavior of components largely depend on the bond behavior, a node-to-node contact between reinforcement and concrete was used. Therefore, a specific bond model was implemented. In the longitudinal reinforcement direction, the bond model implemented defines the bond resistance as a function of the relative displacements between concrete and reinforcement.
      PubDate: 2017-02-23T18:40:53.636607-05:
      DOI: 10.1002/suco.201600077
       
  • Residual compressive stress-strain relation of recycled aggregate concrete
           after exposure to high temperatures
    • Authors: Haifeng Yang; Liangsheng Lv, Zhiheng Deng, Wenwu Lan
      Abstract: The complete compressive stress-strain curve of recycled aggregate concrete (RC) after exposure to high temperatures improves to assess the post-fire behavior of reinforced RC structures. In this paper, 60 specimens containing different levels of recycled coarse aggregate (RCA; i.e., 0, 30, 50, 70 and 100%) were produced to study the residual compressive stress-strain relation of RC after exposure to high temperatures. Those specimens designed for thermal temperatures were initially heated to temperatures of 300, 400 and 500°C for 6 hr and then being submitted to test the compressive stress-strain curves after cooling to ambient temperature. The test results were compared with specimens tested at room temperature (about 20°C). The effect of RCA and high temperatures on residual compressive strength, peak strain and elastic modulus are discussed and the empirical formulas for these parameters are also established. The recommended equation for the compressive constitutive relation for conventional concrete in the Chinese code for the design of concrete structures (GB50010-2010) was adopted to fit the test data and was shown to be applicable to heated RC for different temperatures.
      PubDate: 2017-02-21T19:40:37.136488-05:
      DOI: 10.1002/suco.201500153
       
  • Optimization of anchorage corner blisters for posttensioning tendons
    • Authors: Carla Marchão; Válter Lúcio, Hans R. Ganz
      Abstract: The design of anchorage corner blisters for internal continuity posttensioning tendons in bridges built using the cantilever method presents some peculiarities because they are intermediate eccentric anchorages. The simplified formulas for designing the reinforcement required to resist transverse tensile forces due to the application of point loads, as proposed by the current standards, are not sufficient because they do not cover all the effects that require reinforcement. The high density of steel reinforcement in anchorage blisters is the most common reason for problems with concrete cast in situ, resulting in zones with low concrete compactness, which may lead to concrete crushing failures under the anchor plates. The solution to this problem may involve reducing the amount of reinforcement by improving the concrete compressive and tensile strengths. An experimental program was carried out to study the transmission of prestressing force to the slab and web of the box girder, to assess the strut-and-tie models used in design and to investigate the feasibility of using a high-performance fiber-reinforced self-compacting mix (HPFRC) in the blister only, with either in situ or precast solutions. It can be concluded that the use of HPFRC in anchorage blisters is a very interesting solution regarding the savings in materials and the reduction in the steel reinforcement density near the local anchorage zone, with obvious advantages in concrete quality.
      PubDate: 2017-02-21T19:36:40.801993-05:
      DOI: 10.1002/suco.201600057
       
  • Structural performance of ultra-high-performance fiber-reinforced concrete
           beams
    • Authors: Charles Kahanji; Faris Ali, Ali Nadjai
      Abstract: Ultra-high-performance fiber-reinforced concrete (UHPFRC) is a relatively new construction material. In comparison with conventional high-strength concrete, UHPFRC does not usually contain coarse aggregates larger than 6–7 mm in size. This paper presents the outcomes of an experimental study of UHPFRC beams subjected to four-point loading. The effect of two parameters was studied, namely, the fiber content and the temperature of the curing water. Eight UHPFRC beams were tested, comprising six beams reinforced with rebars and two beams without rebars. Three fiber contents were investigated in this study (1, 2, and 4% in volume). The study investigated two curing temperatures of water, 20 and 90°C. The results presented in this paper include deflections, toughness energy, and moment capacity and also includes a comparison with calculations according to EC2 provisions. A minor difference was observed in the deformation and flexural behavior of beams with fiber contents of 1 and 2% (in volume). However, beams with 4% (in volume) fibers exhibited a higher flexural capacity. Only flexural failure was observed and no shear-related failure was recorded. Beams with 1% (in volume) fibers for both curing regimes had the highest peak load toughness energy. Beams reinforced with rebars and cured at 20°C had a significantly higher bending resistance.
      PubDate: 2017-02-21T18:56:06.554248-05:
      DOI: 10.1002/suco.201600006
       
  • Shear load testing of damaged hollow-core slabs
    • Authors: Gregor Schacht; Steffen Marx, Guido Bolle
      Abstract: As a result of poor-quality sealing, moisture and deicing agents had penetrated into the prestressed hollow-core slabs of the top floor of an uncovered parking deck. The slabs showed especially severe chloride-induced damage in the support regions near the joints. Owing to the damage, the theoretical shear capacity according to the technical approval of these slabs was highly questionable. The influence of the damage on the shear capacity of the slabs with different levels of damage was determined with the help of an experimental in situ loading test. Based on the results, the number of slabs that had to be replaced or repaired could be reduced. For the experimental investigation of the shear capacity of the hollow-core slabs, a combination of photogrammetry, acoustic emission analysis, and curvature measurement for each section was used to determine the initial shear damage on a very low level during the test. The comparison of the results of the different measuring techniques allowed the damage processes to be clearly identified and significantly increased the quality of information about the structural condition of the slabs during the experimental investigation.
      PubDate: 2017-02-20T20:06:48.562481-05:
      DOI: 10.1002/suco.201600082
       
  • Experimental investigation of the mechanical properties of basalt
           fiber-reinforced concrete
    • Authors: Sruthi Jalasutram; Dipti Ranjan Sahoo, Vasant Matsagar
      Abstract: This paper presents an experimental investigation of how varying the volume fraction of chopped basalt fibers affects the mechanical properties of fiber-reinforced concrete (FRC). The fiber content is varied in the range of 0–2%. The main parameters investigated are workability, compressive strength, splitting tensile strength, flexural strength, and flexural toughness. Test results showed that the compression strength of concrete decreased marginally with the addition of basalt fibers in comparison with plain concrete. However, the mode of failure of FRC under compression is changed from the brittle to ductile. The splitting tensile strength of concrete is improved by 15% when basalt fibers with 2% volume fraction are added to the concrete mix. A significant increase of up to 75% is noticed in the flexural tensile strength of basalt FRC, with better post-peak residual strength compared with the plain concrete. Furthermore, the flexural toughness of basalt FRC is increased by nearly three times that of the plain concrete based on the round panel tests.
      PubDate: 2017-02-19T18:35:42.934417-05:
      DOI: 10.1002/suco.201500216
       
  • Relation between the compressive strength and modulus of elasticity of
           concrete with crushed brick and roof tile aggregates
    • Authors: Ivana Miličević; Nina Štirmer, Dubravka Bjegović
      Abstract: This paper presents the results of experimental research into the effect of brick and roof tile aggregates on the values of the modulus of elasticity of concrete made with crushed brick and roof tile aggregates. The main purpose of this paper is to compare the formulae given in the code provisions for estimating the concrete elastic moduli for lightweight and normal-weight concretes with values obtained experimentally. Sixty two different concrete mixes including crushed brick and roof tiles were made and tested experimentally. The differences between the empirical and experimental static moduli of elasticity are shown. In addition, formulae for calculating the static modulus of elasticity over compressive strength are shown and compared with an experimentally estimated formula. As a result of this investigation, a universal equation for estimating the static modulus of elasticity over compressive strength for concretes with crushed brick and roof tile aggregates is proposed.
      PubDate: 2017-02-19T18:30:28.466734-05:
      DOI: 10.1002/suco.201500207
       
  • Dynamic response assessment in compliance with the Eurocodes for the
           elevated viaducts of the Doha Metro Green Line
    • Authors: Essam Ayoub; Sameh Mehanny, Charles Malek, Gamal Helmy
      Abstract: The double-track elevated viaducts of the Doha Metro Green Line, which is currently under construction, are 2.7-km long and consist of in situ and precast segmental simply supported spans ranging from 20 to 35 m and in situ two- and three-span continuous (39.5–57, 50–51–44, and 37–68–37 m) U-trough decks. The nontypical configuration of the continuous spans was imposed due to utilities and infrastructure requirements. All viaduct decks (in situ and precast) are posttensioned to minimize any concrete cracking. To ensure passenger comfort and traffic safety during train operation, performing a dynamic analysis was vital. The dynamic analysis focused on the vertical accelerations and vertical displacements. The actual train of the project, comprising six vehicles with a total length of 120 m and with actual axle loads (max. axle load = 160 kN, with four axles per vehicle), was adopted in the dynamic analysis. The analysis was carried out using both direct time integration of the equation of motion and modal time history analysis for different train speeds ranging from 60 km/hr to the maximum permissible speed along the metro line (160 km/hr). The maximum vertical accelerations and maximum vertical deflections were monitored for each train speed using the CSiBridge software used in the current project and compared with the allowable values given in EN 1991-2 and EN 1990, Annex 2. According to relevant Eurocodes requirements, the vertical accelerations and the vertical deflections were found to be acceptable.
      PubDate: 2017-02-19T18:25:34.135108-05:
      DOI: 10.1002/suco.201600072
       
  • Physical–mechanical behavior of concretes exposed to high temperatures
           and different cooling systems
    • Authors: Germán Ercolani; Néstor F. Ortega, Carla Priano, Lilia Señas
      Abstract: Over their lifetime, concrete structures can suffer from different pathologies, one of them is exposure to high temperatures, which diminishes their load-bearing capacity. This study describes how different concrete types were exposed to high temperatures. To simulate fire extinction, where the temperature of the overheated concrete descends suddenly, different cooling systems were applied: slowly cooling in the open air and fast cooling by spraying different water volumes. Several physical–mechanical characteristics were analyzed such as compressive strength, splitting tensile strength, porosity, capillary suction, and carbonation depth. Ultrasound nondestructive tests were conducted to quantify deterioration. A petrographic study using a stereomicroscope and microscopy of polarization was performed on thin sections to evaluate aggregate composition and concrete characteristics, focusing on interface areas. Physical and mechanical properties were affected by the increase in temperature, with damage worsening through the appearance of cracks and microcracks when water is used as a cooling system.
      PubDate: 2017-02-16T18:25:33.870933-05:
      DOI: 10.1002/suco.201500202
       
  • Simplification and verification of dual potential capacity model for
           reinforced concrete beams subjected to shear
    • Authors: Deuck Hang Lee; Sun-Jin Han, Jin-Ha Hwang, Hyunjin Ju, Kang Su Kim
      Abstract: In the authors' previous study, the dual potential capacity model (DPCM) was proposed to evaluate the shear strengths of reinforced concrete (RC) members, in which the shear contributions of both the cracked tension zone and the compression zone are considered. In this paper, the main concept and formulations of the proposed DPCM were briefly introduced, and the simplified DPCM was developed for the practical application of the proposed model. A total of 1019 data sets of shear test results on RC members were collected for detailed verifications of the detailed and simplified DPCM. The verification results demonstrated that the proposed models can appropriately assess the effects of key influential factors including compressive strength of concrete, shear span-to-depth ratio, size of coarse aggregate, sizes of members, and shear reinforcement on the shear strengths of RC members.
      PubDate: 2017-02-16T18:20:40.698019-05:
      DOI: 10.1002/suco.201600055
       
  • Investigation of the impact behavior of steel and composite pipes with
           protective layer
    • Authors: Özgür Anil; S. Oğuzhan Akbaş, Onur Gezer, M. Cem Yılmaz
      Abstract: A free-fall impact apparatus was used in this study to examine the behavior of steel and composite pipe systems designed with three different protective layers, considering both the efficiency and the energy adsorption capacity under impact loading. The three protective layers considered in this study are a granular soil layer of constant relative density and sand layers reinforced with geotextile and geogrid layers. The magnitudes of the impact loads as well as the resultant accelerations on the pipes were measured as a function of time during the experiments. Time histories of accelerations recorded in each test were used to calculate the displacements and loads on the pipes, which in turn led to estimates of the level of energy adsorbed by the protective layer systems. This enabled a fair comparison of the relative performance of each protective layer under impact load conditions. It was observed that all three protective systems contributed significantly to pipe safety. However, both the experimental results and the supporting finite element analyses indicate that the most successful pipe performance was achieved through the use of a geotextile-reinforced soil layer. Furthermore, it was observed that the composite pipe has a higher energy adsorption capacity compared with the steel pipe, making it less vulnerable to impact forces under the same protection conditions.
      PubDate: 2017-02-16T18:15:47.657037-05:
      DOI: 10.1002/suco.201600128
       
  • Erratum
    • PubDate: 2017-02-16T18:05:27.122668-05:
      DOI: 10.1002/suco.201700130
       
  • Engineering field tests for alkali-aggregate reaction
    • Authors: Paulo Helene; Mariana Carvalho, Jéssika Pacheco
      Abstract: The Paulo Guerra Bridge in Recife, Brazil, was constructed in 1977. After about 15 years some pathological symptoms appeared, such as map cracking, concrete expansion, steel corrosion, and leaching stains. This paper presents a discussion of the specific inspections conducted, which included visual observation of the foundation blocks (pile caps), core extraction, ultrasonic pulse velocity tests, carbonation tests, measurements of chloride concentration, electrochemical resistivity, corrosion potential, compressive strength, and modulus of elasticity as well as X-ray diffraction and microscopy evaluations. The results of the inspection showed the occurrence of generalized alkali-aggregate reactions (AARs) on the pile caps (foundation blocks) of the bridge. The recommended repair for the pile caps was confinement to resist tensile stresses of 4 MPa.
      PubDate: 2017-02-16T18:00:42.853417-05:
      DOI: 10.1002/suco.201600090
       
  • Limitations of the use of concrete bulk resistivity as an indicator for
           the rate of chloride-induced macro-cell corrosion
    • Authors: Karla Hornbostel; Bernhard Elsener, Ueli M. Angst, Claus K. Larsen, Mette R. Geiker
      Abstract: An experimental setup was designed to study the impact of concrete bulk resistivity on the rate of chloride-induced reinforcement corrosion. Small pieces of mild steel were used to simulate pits (anodes) that form when chlorides come into contact with the reinforcement. The galvanic current was measured between the simulated anodes and a large cathode network. Comparisons were made between the corrosion rates calculated from the galvanic currents and the bulk resistivity. The bulk resistivity was varied using two mortar mixes (made of plain Portland cement and a Portland cement—fly ash blend), which were exposed in different temperature and moisture conditions. Despite a high scatter in the results, it was clear that the relationship between bulk resistivity and corrosion rate depended on the mortars tested. The findings presented in this article and the accompanying work strongly indicate that bulk resistivity alone does not provide sufficient information for assessment of the corrosion rate for chloride-induced macro-cell corrosion.
      PubDate: 2017-02-16T17:55:28.558351-05:
      DOI: 10.1002/suco.201500141
       
  • Issue Information: Structural Concrete 1/2017
    • Pages: 1 - 2
      PubDate: 2017-03-22T18:06:50.866591-05:
      DOI: 10.1002/suco.1091
       
  • A new year means changes for our journal
    • Authors: Luc Taerwe
      Pages: 3 - 3
      PubDate: 2017-03-22T18:06:47.022782-05:
      DOI: 10.1002/suco.1077
       
  • Integrate and conciliate knowledge, trade and will to give more prominence
           to Structural Concrete
    • Authors: Hugo Corres Peiretti
      Pages: 4 - 4
      PubDate: 2017-03-22T18:06:48.160724-05:
      DOI: 10.1002/suco.1078
       
  • fib-news: Structural Concrete 1/2017
    • Pages: 237 - 245
      PubDate: 2017-03-22T18:06:50.558448-05:
      DOI: 10.1002/suco.201700127
       
  • Nondestructive assessment of corrosion of reinforcement bars through
           surface concrete cracks
    • Authors: Antonio Bossio; Gian Piero Lignola, Francesco Fabbrocino, Tullio Monetta, Andrea Prota, Francesco Bellucci, Gaetano Manfredi
      Abstract: Degradation of reinforced concrete (RC) structures is a serious safety problem affecting all industrialized countries, and economical aspect of this problem cannot be neglected. One of the main reasons for the degradation of RC is the corrosion of steel reinforcing bars as a result of concrete cover cracking and bar cross section reduction. As a consequence, the structural capacity of reinforced concrete elements decreases progressively as degradation develops. The use of nondestructive testing (NDT) and/or analytical formulation can represent high-quality and rapid methods to evaluate the corrosion penetration of bars, and provide a useful parameter to design a retrofit. This paper presents an additional tool that can be used to evaluate and assess the vulnerability of existing structures in terms of determination of bar cross section lost. This can be accomplished by calculating reinforcing bar cross section loss due to corrosion by measuring external crack widths of the concrete cover by using simple charts and formulas. Predictions were obtained by using two analytical models, developed by the authors. Their predictions have been satisfactorily compared to both the literature and novel experimental results, and compared to previous empirical models available in scientific literature. The experimental results were obtained by corroding real scale concrete specimens reinforced by using smooth and ribbed bars (according to old and modern building codes) using 3.5%wt sodium chloride solution and an imposed current.
      PubDate: 2016-10-31T08:35:59.787695-05:
      DOI: 10.1002/suco.201600034
       
  • Butterfly web effects on bridge design
    • Authors: Akio Kasuga
      Abstract: A new type of bridge called „Butterfly Web Bridge” has been constructed in Japan. In a butterfly web bridge, the panels used as the web are cut so as to appear pinched in the centre, giving a butterfly-wing shape. 80 MPa steel fibre reinforced concrete is used for the butterfly shaped web made of precast panels with a thickness of 150 mm. After the shear tests of butterfly webs, the design method was proposed. In this paper, four projects of expressway bridges using this new technology will be shown. By a simplified construction process, construction time can be reduced. Then, future development will be proposed in the last part of this paper. It is a 500-m-span extradosed bridge. The butterfly web technology will greatly affect bridge design and construction in the near future.
      PubDate: 2016-10-28T03:26:53.204185-05:
      DOI: 10.1002/suco.201600109
       
  • Experimental Investigation of Continuous Two-Layer Reinforced Concrete
           Beam
    • Authors: Y. Ribakov; Iakov Iskhakov, Klaus Holschemacher
      Abstract: Models and full-scale statically determinate two-layer beams (TLB), made of steel fibre high strength concrete (SFHSC) in the compression zone and normal strength concrete (NSC) in the tensile zone, have been tested by the authors. The present study is a further stage of these investigations, focused on testing a continuous two span TLB with optimal steel fibre ratio as in the previous stages. This is the first experimental investigation of continuous TLB (CTLB). The study is aimed at testing the CTLB behaviour under positive and negative bending moments in the span and above the middle support respectively. An additional issue that is studied in the course of this work is the influence of bending moment redistribution on the behaviour of a CTLB. As in the previous research stages, interaction of the concrete layers in a CTLB was studied to demonstrate the efficiency of such beams for real structures. No cracks between the SFHSC and NSC layers were observed up to the ultimate limit state of the tested beam, which demonstrates proper interaction between the layers. The results obtained in the present study enable a recommendation of CTLB for practical application as effective and economical continuous bending elements.
      PubDate: 2016-10-21T09:30:21.16048-05:0
      DOI: 10.1002/suco.201600027
       
  • NUMERICAL MODELLING OF CONCRETE BEAMS AT SERVICEABILITY CONDITIONS WITH A
           DISCRETE CRACK APPROACH AND NON-ITERATIVE SOLUTION-FINDING ALGORITHMS
    • Authors: Daniel Dias-da-Costa; Ricardo Carmo, Rui Graça-e-Costa
      Abstract: This paper describes the development and validation of a comprehensive numerical model enabling the simulation of reinforced concrete beams at serviceability conditions using a discrete crack approach. The highly non-linear behaviour introduced by the different material models and the many cracks localising and propagating within the member pose a challenging task to classic iterative solvers, which often fail to converge. This limitation is solved with a non-iterative solution-finding algorithm, in which a total approach was used to overcome critical bifurcation points. The finite element model was validated using experimental data concerning lightweight aggregate concrete beams under flexural loading. The model was shown to properly simulate both overall and localised features of the structural response, including curvature, crack openings and crack patterns. The model was used to carry out a numerical study on the role of the longitudinal reinforcement ratio and crack widths in reinforced concrete beams. It was observed that the total crack openings along the member seem to remain nearly independent of the tensile reinforcement for ratios above 2.5% and the same level of strength.
      PubDate: 2016-10-18T01:05:30.029724-05:
      DOI: 10.1002/suco.201600130
       
  • Slenderness Limits for deflection control: a new formulation for flexural
           RC elements
    • Authors: ALEJANDRO PéREZ CALDENTEY; Javier Mendoza Cembranos, Hugo Corres Peiretti
      Abstract: The first step in the design of a structure is the definition of the geometry. This process includes the definition of the depth of slabs and beams. The depth of a flexural member is often determined by control of deflections, which can only be checked in detail at an advanced stage of the project. In order to optimize the design process, it is therefore very important to choose well the span-to-depth ratio at the beginning. In order to achieve this task in an easy manner a lower limit to the slenderness of the beams in terms of span divided by the effective depth is proposed in most major codes. However, current proposals are rather coarse and are not necessarily on the safe side. In this paper a new formulation for the slenderness limits, based on the physics of the problem, is presented. This formulation includes the effect of the composition of the load (live load to total load ratio) as well as the possibility of using different limits to maximum deflection and considering different, more general, support conditions. It is therefore more complete and has a larger application field than current proposals.
      PubDate: 2016-09-26T07:58:25.983806-05:
      DOI: 10.1002/suco.201600062
       
  • Strengthening Corbels Using Post – Installed Threaded Rods
    • Authors: Tadeusz Stanisław Urban; Łukasz Krzysztof Krawczyk
      Abstract: The paper presents the results of experimental research in which post-installed threaded rods were used as additional reinforcement. An increase in load-carrying capacity of up to 64% was obtained for strengthened corbels, in comparison with unstrengthened corbels (reference corbels). Calculations of the load-carrying capacity of corbels have been performed using a model developed on the basis of the literature and the obtained results were confronted with results calculated according to the EN 1992-1-1. Strain diagrams for primary reinforcement, stirrups and the compressed surface of concrete are presented, alongside with a description of the development of cracking and photographs of the corbels after failure. In the second chapter, publications on calculating the load-carrying capacity of corbels and on different reinforcement methods are quoted.
      PubDate: 2016-09-01T03:11:00.124294-05:
      DOI: 10.1002/suco.201500215
       
  • Mechanism of Shear Strength Degradation of RC Column Subjected to Cyclic
           Loading
    • Authors: Li Fu; Hikaru Nakamura, Hiroki Furuhashi, Yoshihito Yamamoto, Taito Miura
      Abstract: The purpose of this study was to investigate the mechanism of shear strength degradation of RC member under cyclic loading. First, the shear failure after flexural yield of tension reinforcing bars of a RC column designed as bridge pier under cyclic loading was simulated by the method of three dimensional Rigid-Body-Spring-Model (3-D RBSM) and the shear strength degradation was quantitatively evaluated by a numerical approach. Afterwards, based on the shear resistant mechanism, the degraded shear strengths after each load cycle were decoupled into the contributions provided by beam action and arch action, with the use of the numerical local stress results. As the important finding, the mechanism of shear strength degradation due to cyclic loading of the RC column was concluded as with the increase of deformation level, the arch action first degraded gradually whereas the beam action maintained its original capacity; then after losing most capacity of the arch action, the beam action began to decrease rapidly, which caused the shear failure.
      PubDate: 2016-07-12T05:51:13.684387-05:
      DOI: 10.1002/suco.201600052
       
  • ELASTIC MATERIAL PROPERTY INVESTIGATION OF CLASS G CEMENT
    • Authors: Dogukan Guner; Hasan Ozturk, Mustafa Erkayaoglu
      Abstract: Class G cements are sulphate-resistant Portland cements with different setting time requirements and have a common usage field in the oil industry. Compared to other API class cements, Class G has a utilization of more than 95% worldwide in oil well applications. Different additives are used together with Class G cement to achieve optimum hardening conditions. In this study, elastic material properties of high sulphate resistant (HSR) Class-G cements are investigated for a special case implemented in solution mining. There are no published studies on the mechanical properties of Class G oil well cements for more than three days of curing time and various water cement ratio to date. Uniaxial compressive strength, Young's modulus, and Poisson's ratio determination are carried out on a total of 108 samples with different curing times (2, 7, and 14 days) and water-cement ratios (0.4, 0.5, 0.6, and 0.8). Laboratory results were subject to Dixon's Q-test for outlier elimination and were analysed by fitting a multi-variable non-linear regression model to estimate uniaxial compressive strength and Young's modulus.
      PubDate: 2016-07-12T05:45:26.114553-05:
      DOI: 10.1002/suco.201600020
       
  • ARE FIBRES SENSITIVE FOR MIXING'
    • Authors: Olivér Czoboly; György L. Balázs
      Abstract: The post-cracking behaviour of fibre reinforced concrete is mostly influenced by the fibre type, the amount of fibres, fibre orientation and the concrete strength. Manufacturers of fibres propose a minimum mixing duration after fibres are added to concrete to obtain an acceptable dispersion of fibres. What about the maximum mixing time' Fibre properties (tensile strength, length, surface characteristics, shape and density) are normally specified by the fibre producer. However, the properties of hardened FRC (fibre reinforced concrete) are influenced by the properties of fibres after mixing. An important question is whether the properties of fibres change due to an occasionally long mixing time. Can surface characteristics, length or tensile strength of fibres change during mixing and can this affect the properties of FRC' In an extensive experimental study two types of macro polymer fibres, two types of steel fibres (without coating or with brass-coating), two basalt fibres (with different lengths), two braids of hemp fibres (without protection and with lensed oil protection) were tested. The test results indicate possible deterioration for some of the fibres in concrete for too long mixing times. Possible modes of deterioration are shown.
      PubDate: 2016-06-13T07:15:32.192054-05:
      DOI: 10.1002/suco.201600039
       
  • Test and Analysis of a New Ductile Shear Connection Design for RC Shear
           Walls
    • Authors: Jesper H. Sørensen; Linh Cao Hoang, John F. Olesen, Gregor Fischer
      Abstract: This paper presents a new and construction-friendly shear connection for assembly of precast reinforced concrete shear wall elements. In the proposed design, the precast elements have indented interfaces and are connected by a narrow zone grouted with mortar and reinforced with overlapping U-bar loops. Contrary to the classical shear connections, the planes of the U-bar loops are here parallel to the plane of the wall elements. This feature enables a construction-friendly installation of the elements without the risk of rebars clashing. The core of mortar inside each U-bar loop is reinforced with a transverse double T-headed bar to ensure transfer of tension between the overlapping U-bars. Push-off tests show that a significantly ductile load-displacement response can be obtained by the new solution as compared to the performance of the conventional keyed shear connection design. The influence of the interface indentation geometry was investigated experimentally and the failure modes in the push-off tests were identified by use of digital image correlation (DIC). For strength prediction, rigid plastic upper bound models have been developed with inspiration from the observed failure mechanisms. Satisfactory agreement between tests and calculations has been obtained.
      PubDate: 2016-06-13T07:15:27.87812-05:0
      DOI: 10.1002/suco.201600056
       
  • Experimental and non-linear numerical analysis of underwater housings for
           the deep sea made of ultra-high performance concrete (UHPC)
    • Authors: Sebastian Wilhelm; Manfred Curbach
      Abstract: The paper describes the design and analysis of underwater housings made of ultra-high performance concrete (UHPC) within the Helmholtz Alliance "ROBEX" to provide cost efficient alternatives to expensive titanium housings [2]. The research is related to former investigations on spherical und cylindrical shells under hydrostatic pressure made of normal strength concrete, performed from 1960 to 1980 at the Civil Engineering Laboratory, Port Hueneme, California. Several housings made of UHPC have been manufactured and the short-term implosion resistance has been determined experimentally. Since neither the mechanical equations for thin- or thick-walled shells nor the empirical equations for implosions pressure of shells made of normal strength concrete by ALBERTSEN [1] can describe the behaviour sufficient, two non-linear material laws for concrete, multiPlas Law 9 (modified WILLAM-WARNKE model) and Law 14 (MENETREY-WILLAM model) by DYNARDO for ANSYS, have been calibrated with results from uni- and biaxial strength tests and the results of non-linear FEM with ANSYS 16 have been compared. To study the long-term behavior, an in-situ test at the arctic sea at 2,500 m is currently performed.
      PubDate: 2016-06-10T09:05:24.598689-05:
      DOI: 10.1002/suco.201600018
       
  • Roofs from Prestressed Concrete Membranes
    • Authors: Jiri Strasky; Pavlina Juchelkova, Pavel Kalab, Radim Nečas
      Abstract: Prestressed membrane roofs have been designed from the beginning of prestressed concrete. They are described in basic books written by pioneers of prestressed concrete. For illustration, four architecturally most successful roofs are reminded. The authors are convinced that the prestressed membrane roofs are still modern, structurally efficient and architecturally interesting. If they are assembled of precast members, they can be erected without scaffolding. Recently they have studied different membrane structures from point of view of their architectural and structural arrangement, process of erection and static and dynamic behavior. Deep studies were done for membranes of simple curvature situated above the whole or portion of the rectangle area and selfanchored membranes supported by arches or shells. Also selfanchored suspension membranes situated above the circular or elliptical plans, hypar membranes and membranes of a free form that are suspended on arches or suspension cables were analyzed.
      PubDate: 2016-06-03T08:09:56.294753-05:
      DOI: 10.1002/suco.201600037
       
  • Component based reinforced concrete beam-column joint model
    • Authors: Ricardo Costa; Paulo Providência, Alfredo Dias
      Abstract: A reinforced concrete beam-column (RCBC) joint model for the quasi-static monotonic analysis of cast in situ reinforced concrete (RC) frames is developed and implemented in a finite element analysis program for framed structures. The joint model was developed in the framework of the component method, a method originally developed for steel joints, which consists of three steps: (i) identification of the joint relevant basic components, their interaction and contribution to overall joint behaviour, (ii) characterization of the mechanical behaviour of each component and (iii) assembling of the components. With regard to the model implementation, the materially nonlinear analysis is performed by the Fictitious Forces method ⊮ all the required steps being presented and explained ⊮ while the P-Δ method for the geometrically nonlinear analysis of frames is extended to include the beam-column joint model. The paper closes with illustrative and validation examples; while some of these are fully analytical the others simulate lab tested sub-frames subjected to quasi-static monotonic loads.
      PubDate: 2016-06-02T05:32:42.868416-05:
      DOI: 10.1002/suco.201600024
       
  • EXPERIMENTAL INVESTIGATIONS ON CONCRETE EDGE FAILURE OF MULTIPLE ROW
           ANCHORAGES WITH SUPPLEMENTARY REINFORCEMENT
    • Authors: Akanshu Sharma; Rolf Eligehausen, Jörg Asmus
      Abstract: The presence of supplementary reinforcement, in the form of edge reinforcement and stirrups, has a significant influence on the load-carrying capacity of the anchorage groups with multiple anchor rows loaded in shear perpendicular to the edge. The current models available in the codes and standards are conservative for low to medium amounts of supplementary reinforcement but tend to be unconservative for high amounts of reinforcement. This paper presents the results of a comprehensive test program carried out to investigate the behavior of anchor groups with supplementary reinforcement loaded in shear towards the edge. The test results are discussed in detail to highlight the influence of supplementary reinforcement on load carrying capacity of the anchorages. Based on the evaluation of these test results, a realistic and rational model has been developed to predict the concrete edge failure loads for anchorages with supplementary reinforcement that will be presented in another paper.
      PubDate: 2016-05-20T03:51:16.601422-05:
      DOI: 10.1002/suco.201600015
       
  • Functionally Graded Concrete – Numerical Design Methods and Experimental
           Tests of Mass-Optimised Structural Components
    • Authors: Michael Herrmann; Werner Sobek
      Abstract: Functional gradation of concrete elements makes it possible to align the internal composition of structural components with specific structural and thermal performance requirements. This alignment is made possible by continuously altering the characteristics of the material, including its porosity, strength or rigidity, in up to three spatial dimensions. This principle can be applied to minimise the mass of the element and to create multifunctional properties. Numerical design methods are used to develop the gradation layout that serves as a digital blueprint for such components. This paper describes tests performed on functionally graded beams. These tests have made it possible to derive conclusions with respect to the elements' structural behaviour. These tests also allow for a precise assessment of the weight savings that can potentially be achieved compared to structural components made from normal concrete. Test results were subsequently replicated by numerical simulations. The models calibrated in this step have established the basis to develop numerical design methods that rely on the principle of topology optimisation.
      PubDate: 2016-05-20T03:51:13.852845-05:
      DOI: 10.1002/suco.201600011
       
  • Levels of Approximation for the shear assessment of reinforced concrete
           slab bridges
    • Authors: Eva Lantsoght; Ane de Boer, Cor van der Veen
      Abstract: Since a large number of existing reinforced concrete bridges in the Netherlands are suspected to be insufficient for shear, a methodical approach is necessary. This paper aims at providing a structured approach for assessment, here applied to reinforced concrete slab bridges, which make up a considerable fraction of the Dutch bridge stock. The proposed method uses the Levels of Approximation, introduced in the 2010 fib Model Code. The recommendations at all levels are linked to experimental research. The different levels include spreadsheet-based calculations (the Quick Scan), linear finite element models, non-linear finite element models and analysis of a structure with cracked concrete and, for exceptional cases, proof loading of the structure. The result of this approach is a structured method of Levels of Assessment that can be used when a large number of bridges need to be assessed. For most bridges, assessment at the lowest Level of Assessment will prove sufficient capacity. For a limited number of cases, higher Levels of Assessment will offer options and guidelines for a more in-depth study of the structure that is being assessed.
      PubDate: 2016-05-20T03:51:00.754854-05:
      DOI: 10.1002/suco.201600012
       
  • Drying Shrinkage of Concrete Elements
    • Authors: Marek Vinkler; Jan L. Vitek
      Abstract: The paper deals with shrinkage of large concrete specimens. The segments of walls of the thicknesses 200 mm, 400 mm and 800 mm were cast. Four sides were sealed in order to simulate the drying of the infinite walls of different thicknesses. The elements are equipped with vibrating wire strain gauges which measure strains inside the elements. The strains in vertical as well as in horizontal directions have been recorded for the period of 6 months. The segments of walls are stored in a laboratory. Relative humidity and temperature of the environment are not controlled, but recorded very closely. Additional tests have been executed. The concrete compression strength was measured on cubes and uniaxial shrinkage is measured on standard cylinders using embedded vibrating wire strain gauges. The cylinders are stored in three different environments, in the laboratory and in the rooms with controlled relative humidity of 65 % and 100 %, respectively. A comparison of measured shrinkage with various shrinkage models is provided (Model Code 2010, Eurocode 2, Model B3, Model B4, Model B4s and Model ACI 209R-92).
      PubDate: 2016-05-19T09:05:23.93483-05:0
      DOI: 10.1002/suco.201500208
       
  • Durability of Steam-cured Concrete with Slag under the Combined
           Deterioration of Freezing-thawing Cycles and Deicing Chemicals
    • Authors: Taeseok Seo; Younsu Jung, Junhyung Kim, okpin na
      Abstract: In previous studies on the durability of slag-mixed concrete against the combined impacts of deicing chemicals and freeze-thaw cycles, scaling resistance of concrete was improved using replacement amounts of slag from 25% to 35% of the total cement content. However, the resistance decreased rapidly when the amount of slag replacement increased above 40% of cement content. Furthermore, in these studies, only normal cured concrete products were used rather than steam-cured ones. Thus, the research on the scaling resistance of steam-cured concrete products with slag replacement has not been studied enough. In this study, the durability characteristics of slag-replaced steam-cured concrete against the impacts of concrete deicing chemicals and freeze-thaw cycles were investigated with the aim of improving the quality of precast concrete products. Scaling, chloride ion penetration, pull-off strength, and relative dynamic modulus of elasticity were evaluated for both the pouring and bottom sides of the specimens. This was done because it was expected that the concrete pouring side would suffer more degradation than the bottom side owing to weakened concrete strength caused by bleeding effects.
      PubDate: 2016-05-19T08:35:28.070165-05:
      DOI: 10.1002/suco.201500201
       
  • Improving cracking behaviour with Recycled Steel Fibres, targeting
           specific applications. Analysis according to MC2010
    • Authors: Giancarlo Groli; Alejandro Pérez Caldentey
      Abstract: A new and appealing means of improving cracking behaviour of RC elements is the combined use of rebars and fibres. Previous research has shown Steel Fibres Recycled from End-of-Life Tyres to be effective for this purpose. In this paper practical applications that would benefit from the use of this technique are presented and discussed. Firstly, two previously published examples of crack width calculation according to MC2010 are expanded to the case of study. These practical applications show how a fibre reinforced concrete (FRC) with a rather low post-peak behaviour can provide large improvements in cracking behaviour, being also economically attractive. Then, the case of jointless structures is considered, and the improvements in terms of maximum achievable length are presented and discussed. Finally an analysis regarding the effectiveness of this solution as a function of the reinforcement ratio is discussed for both tension and bending. The main objective of this paper is to encourage the use of Recycled Steel Fibres as an effective and sustainable means of dealing with cracking behaviour for specific applications.
      PubDate: 2016-05-18T08:57:58.247295-05:
      DOI: 10.1002/suco.201500170
       
  • MECHANICAL PROPERTIES OF CONCRETE WITH RECYCLED AGGREGATES AND WASTE GLASS
    • Authors: Viviana Letelier; Ester Tarela, Rodrigo Osses, Juan Pablo Cárdenas, Giacomo Moriconi
      Abstract: The present investigation analyses the mechanical behaviour of concrete with recycled aggregates from precast debris and waste glass. The combination of both recycled materials allows increasing the amount of recycled coarse aggregates reducing the loss in the mechanical performance of the concrete, and enhances the environmental value of the final material. Four variables are considered: the percentage of recycled course aggregates, the amount of mortar adhered to their surface, the amount of cement replaced by recycled glass powder and the maximum size of its particles. The final goal is to determine the significance of each variable in the final product and the most efficient combination to optimize the performance of the concrete, maximizing its environmental value. Significant results have been obtained that show that the calibration of the parameters may not be trivial.
      PubDate: 2016-05-18T05:11:03.978703-05:
      DOI: 10.1002/suco.201500143
       
  • Nanoscale modifier as an adhesive for hollow microspheres to increase the
           strength of high-strength lightweight concrete
    • Authors: Aleksandr S. Inozemtcev; Evgenij V. Korolev, Vladimir A. Smirnov
      Abstract: The paper presents the results of the study of physical-mechanical and operational properties of the high-strength lightweight concrete and influence of nanoscale modifier on these properties. The nanomodifier and method of its application to improve the properties of lightweight concrete with hollow microspheres at 10–25% was proposed. It is shown that the control process of the structure formation of the cement stone which leads to the acceleration of the hydration of portland cement and the formation an additional amount of calcium hydrosilicates at the phase boundary during reaction of nanoscale silicon-oxygen shell grafted onto the surface of the microspheres with the cement hydration products (calcium hydroxide). This provides growth of operational properties. The high-strength lightweight concrete with an average density less than 1500 kg/m3 is characterized by strength more than 40 MPa (specific strength Rspã30 MPa). The optimum range of concentrations of the precursor for preparation of nanomodifier is defined to be 1.25≤[Na+]/[Cl-]≤2.5. We can conclude that the developed compositions has dense and strong structure which can resist intense cracking. Application of nanoscale modifier allows to increase the elastic modulus at 13–36% (it is equal to 6.2–8.5 GPa depending on the average density), to decrease the water absorption (to 1%) and to improve the water resistance (coefficient of water resistance is more than 0.95) and freeze-thaw resistance (up to F300). The nanomodified high-strength lightweight concrete has beneficial values of heat-conduction coefficient (0.48-0.70 W/(m·°C)), temperature conductivity coefficient ((3.43–4.04)·10-7 m2/s) and specific heat capacity (1080–1175 J/(kg·°C)). It allows us to consider this concrete as a multifunctional material with both structural and thermal insulation properties.
      PubDate: 2016-05-17T09:05:25.314655-05:
      DOI: 10.1002/suco.201500048
       
 
 
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