Journal articles
Author(s) | Title | Journal | Issue | Page | Category |
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Taerwe, Luc | Message from the Editor-in-Chief | Structural Concrete | 5/2016 | 697 | Editorials |
Stucchi, Fernando; Ungaretti, Marcelo Coelho; Fujii, Gilson; Peiretti, Hugo Corres; Martin, José Soriano; Doniak, Sérgio | Corinthians Arena - 2014 World Cup, design and construction | Structural Concrete | 5/2016 | 698-709 | Technical Papers |
AbstractThis paper describes the design and construction of the concrete structures of the Corinthians Arena built for the 2014 World Cup. Due to many constraints, the structure was designed, essentially, with prefabricated structural concrete members, some specific elements were designed with structural concrete cast in situ, and some areas, with special construction problems, were designed with composite steel-concrete structures. x | |||||
Godycki- wirko, Tadeusz; Nagrodzka-Godycka, Krystyna; Wojdak, Ryszard | Reinforced concrete thin-wall dome after eighty years of operation in a marine climate environment | Structural Concrete | 5/2016 | 710-717 | Technical Papers |
AbstractThe paper presents a description of the construction elements of the Gdynia Seaport main hall dome. Firstly, it provides information about the technical condition of the dome's structure. Secondly, it examines the strength analysis of the thin-walled reinforced concrete dome covering. Throughout the last 80 years the building has been exposed to an unfavourable marine climate. The analysis of the state of stress and deformations of several construction elements was carried out using a special model worked out with help of the FEM considering the combination of loads: deadweight, wind and snow, as well as the additional combination: deadweight and hurricane wind of velocity 200 km/h(55.5 m/s). The computed results of static quantities were also obtained according to F. Dischinger's method, which was used in design of the RC Gdynia Seaport dome in 1932. The computational analysis and the assessment of the technical state made it possible to make a decision concerning further safe operation of the building. x | |||||
von Greve-Dierfeld, Stefanie; Gehlen, Christoph | Performance-based durability design, carbonation, part 3: PSF approach and a proposal for the revision of deemed-to-satisfy rules | Structural Concrete | 5/2016 | 718-728 | Technical Papers |
AbstractA performance-based safety factor durability design format is proposed and developed with respect to carbonation of concrete. Deemed-to-satisfy rules based on a partial safety factor design approach are developed for the carbonation of concrete. This design format follows the design procedure proposed in EN 1990 [1]. For the design format, the limit state equation for the carbonation is introduced in its probabilistic and safety factor format. The PSF approach has been used to derive design charts. Values for minimum concrete cover depending on material resistance and exposure class are proposed for critical environmental conditions and a design service life of 50 years. x | |||||
Qian, Chunxiang; Zhang, Yi; Huang, Haoliang; Qu, Jun; Guo, Jinqiang | Influences of superplasticizers on the basic and drying creep of concrete | Structural Concrete | 5/2016 | 729-735 | Technical Papers |
AbstractThe influences of naphthalene-based plasticizers and polycarboxylate acid/salt superplasticizers on the creep of concrete, including basic creep and drying creep, were investigated. The internal relative humidity and pore structure of concrete and the surface tension of the pore solution were tested. The results show that polycarboxylate acid/salt superplasticizers refine capillary pores in concrete and reduce the surface tension of the pore solution, and also restrain internal moisture transmission and redistribution. As a result, creep of the concrete is reduced. Compared with naphthalene-based plasticizer, polycarboxylate acid/salt superplasticizer causes a greater reduction of drying creep, but a smaller reduction of basic creep. This is because the moisture redistribution is quite feeble and quickly balanced in a sealed condition. Concrete with polycarboxylate acid/salt superplasticizer has the lowest creep value because polycarboxylate acid/salt superplasticizer improves the degree of hydration and reduces the porosity of macro pores. x | |||||
Daviau-Desnoyers, Dominic; Charron, Jean-Philippe; Massicotte, Bruno; Rossi, Pierre; Tailhan, Jean-Louis | Influence of reinforcement type on macrocrack propagation under sustained loading in steel fibre-reinforced concrete | Structural Concrete | 5/2016 | 736-746 | Technical Papers |
AbstractTo meet the growing challenges of sustainability, it is necessary to control and anticipate the cracking problems of structures under sustained loadings. At the structural level, very little information is available regarding the combined effect of SFRC and reinforcement under sustained flexural loading. This paper presents the results of four flexural creep tests on large steel fibre-reinforced concrete beams reinforced with fibres only or in combination with unbonded/bonded prestressing strands or traditional reinforcing bars. The main objective was to assess the influence of the reinforcement type on crack propagation, crack openings and compliance evolution in SFRC under sustained loading. The results show that the driving mechanism behind crack propagation is the same for all beams, regardless of reinforcement type, and is therefore governed by type of fibre concrete. x | |||||
Di Carlo, Fabio; Meda, Alberto; Rinaldi, Zila | Design procedure for precast fibre-reinforced concrete segments in tunnel lining construction | Structural Concrete | 5/2016 | 747-759 | Technical Papers |
AbstractThis paper presents a procedure for designing precast tunnel segments for mechanically excavated tunnel linings in fibre-reinforced concrete, without any traditional steel reinforcement. Both ultimate and serviceability limit states are considered as well as structural checks at different construction stages of the segment, including demoulding, positioning on floor, storage, transportation, handling and the final stage concerning the loads due to the ground pressure. x | |||||
Nguyen, Viet Anh; Jesse, Frank; Curbach, Manfred | Experiments to establish the loadbearing behaviour of lightweight sandwich beams using textile-reinforced and expanded polystyrene concrete | Structural Concrete | 5/2016 | 760-767 | Technical Papers |
AbstractTextile-reinforced concrete (TRC) is a combination of small-grain high-performance concrete (HPC) and high-strength textile reinforcement. TRC enables thin layers and has high tensile and compressive strengths. In this paper, TRC was used for the face layers and combined with a core of lightweight expanded polystyrene concrete (EPC) to create lightweight sandwich beams without special joint reinforcement to connect the layers. The experimental testing of the loadbearing behaviour of this kind of sandwich beam, along with the influence of the shear span-to-depth ratio (a/d) as observed during three- and four-point bending tests, will be summarized. The failure behaviour of the sandwich beams is influenced by the shear span-to-depth ratio, the type of bending test and the tensile capacity of the TRC layer. A diagonal tension failure occurred in experimental beams with 2.6 ≤ a/d ≤ 5.2 in three-point bending tests and 3.1 ≤ a/d ≤ 4.1 in four-point tests. The shear strength of the beams could be conservatively estimated according to the current European standards. x | |||||
Ma, Chau-Khun; Awang, Abdullah Zawawi; Garcia, Reyes; Omar, Wahid; Pilakoutas, Kypros | Behaviour of over-reinforced high-strength concrete beams confined with post-tensioned steel straps - an experimental investigation | Structural Concrete | 5/2016 | 768-777 | Technical Papers |
AbstractThis study examines the flexural behaviour of high-strength concrete (HSC) beams confined using an innovative steel strapping tensioning technique (SSTT) able to provide active confinement. Twelve over-reinforced HSC beams (fc &equals: 50 or 80 MPa) were designed to fail prematurely by concrete crushing at mid-span. The mid-span region of eight such beams was confined externally using the SSTT with different steel strap confinement ratios, the aim of which was to delay concrete crushing. The test results are discussed in terms of the failure modes, load-deflection response and the concrete and tensile reinforcement strains observed. Although the unconfined beams failed in a brittle manner with no post-peak deflection, the steel straps were very effective at enhancing the post-peak deformation of the SSTT-confined beams by up to 126 %. Moreover, for the beams tested in this study, the use of the SSTT led to failures after yielding of the tensile reinforcement. The proposed SSTT can be used to confine HSC elements where ductility is required. x | |||||
Yu, Qiang; Le, Jia-Liang; Hubler, Mija H.; Wendner, Roman; Cusatis, Gianluca; Ba ant, Zden k P. | Comparison of main models for size effect on shear strength of reinforced and prestressed concrete beams | Structural Concrete | 5/2016 | 778-789 | Technical Papers |
AbstractThis paper presents a critical comparison of the existing code provisions for the shear strength of concrete beams. The comparison is based on the computerized filtering-out of the inevitable statistical bias from the available multivariate database on shear strength, on an examination of the predicted size effects on shear strength and their underlying hypotheses and on the results of recent high-fidelity numerical simulations of shear failure. In addition to examining the existing models, the present comparison also provides several key considerations for testing the scientific soundness of any model of shear failure in concrete beams, which is necessary for future revisions to the design code provisions. x | |||||
Yang, Yuguang; den Uijl, Joop; Walraven, Joost | Critical shear displacement theory: on the way to extending the scope of shear design and assessment for members without shear reinforcement | Structural Concrete | 5/2016 | 790-798 | Technical Papers |
AbstractThis paper presents a new theory for the shear capacity of reinforced concrete members without shear reinforcement. While recognizing that there are multiple failure mechanisms, the theory attributes the opening of a critical flexural shear crack as the lower bound of the shear capacity. It proposes that the shear displacement of an existing flexural crack can be used as the criterion for the unstable opening of the critical flexural shear crack. Based on the theory, the paper presents a simplified shear evaluation model. Compared with the current shear provisions in the design codes, the model is characterized by good accuracy and a solid physical background. It demonstrates a great flexibility for dealing with complex design conditions. As an example, the paper discusses the possibility of extending the theory to the shear resistance of higher-strength concrete. The suggested method provides a more logical and fluent transition from normal- to high-strength concrete and shows good agreement with experimental observations. x | |||||
Brantschen, Fabio; Faria, Duarte M.V.; Ruiz, Miguel Fernández; Muttoni, Aurelio | Bond behaviour of straight, hooked, U-shaped and headed bars in cracked concrete | Structural Concrete | 5/2016 | 799-810 | Technical Papers |
AbstractMost classic investigations on bonding properties in reinforced concrete have been performed on the basis of pull-out tests, where a reinforcement bar is pulled out from an uncracked concrete cylinder, prism or cube. In these tests, the bond is governed by the concrete strength and bar surface properties of the reinforcement (bond index, rib geometry) or by the splitting strength of the concrete (concrete cover). In the latter case, bond failure occurs due to uncontrolled cracking of the concrete specimen. In contrast to these fundamental tests, bond in many structural members is activated within already cracked concrete. This is particularly relevant for the reinforcement in beams and slabs (both for flexural and transverse reinforcement), as the reinforcing bars might be located at planes where flexural cracks develop. The opening of these cracks along the reinforcement is nevertheless not uncontrolled (as opposed to splitting failures), but it is governed by the bending deformations. The bond properties and strength of the reinforcement in actual members are therefore influenced by the opening of these cracks and are potentially different from those observed in classic pull-out tests. x | |||||
Figueira, Diogo; Sousa, Carlos; Calçada, Rui; Neves, Afonso Serra | Design recommendations for reinforced concrete interfaces based on statistical and probabilistic methods | Structural Concrete | 5/2016 | 811-823 | Technical Papers |
AbstractA concrete interface is a material discontinuity that requires special care with respect to structural design and assessment. Therefore, the definition of design expressions based on experimental testing data must ensure the necessary reliability depending on the type of structure and its use. The present work describes a new proposal for the design of concrete interfaces subjected to shear loading for different roughness profile types. The proposal is characterized by three linear branches (for monotonic loading) and an S-N curve (for cyclic loading) and is the result of a parametric analysis of existing experimental data (obtained by the authors and also from an extensive literature search) based on statistical and probabilistic methods. Design expressions were defined in order to minimize the dispersion and variability of the safety factor values for each experimental test considered and also to assure that those values are within a target range (defined according to reliability considerations). These improvements became clearer when the new proposal was compared with the most common design code recommendations. x | |||||
Villalba-Herrero, Sergi; Casas, Joan R. | New structural joint by rebar looping applied to staged box girder bridge construction. Static tests | Structural Concrete | 5/2016 | 824-835 | Technical Papers |
AbstractThe paper describes the design, development and experimental checking of a modified type of structural joint with limited length between concrete segments cast in-situ. The design concept is based on the developed length of an anchorage hook stiffened by transverse reinforcement bars and is particularly suited for the case of in-situ construction of staged box girder bridges, with the intention of possibly using lighter scaffolding. x | |||||
Yanaka, Makoto; Ghasemi, Seyed Hooman; Nowak, Andrzej S. | Reliability-based and life-cycle cost-oriented design recommendations for prestressed concrete bridge girders | Structural Concrete | 5/2016 | 836-847 | Technical Papers |
AbstractThere are several methods available to decide appropriate design recommendations to prevent corrosion of reinforcing steel in prestressed concrete bridge girders. With respect to chloride-induced corrosion, in the present study two methods are considered. The first one is based on the target probability of corrosion initiation and the initial cost. The other method is based on the life-cycle cost that includes the initial cost, maintenance cost, and expected failure cost. This paper deals with the development of recommendations for durability design of structures in marine environments from the reliability point of view, taking into consideration the life-cycle cost of a structure. In order to address the problem, the chloride diffusion coefficient of a cracked area under service load is obtained considering opening and closing motion of cracks. Utilizing the diffusion coefficient of a cracked area, the development over time of the chloride concentration at the surface of reinforcement can be predicted. This information is used to quantify the probability of initiation of corrosion of prestressing steel as well as the distribution of life-cycle cost. Based on the findings, recommendations for durability design in various exposure environments are developed. x | |||||
Colajanni, Piero; Recupero, Antonino; Spinella, Nino | Increasing the flexural capacity of RC beams using steel angles and pre-tensioned stainless steel ribbons | Structural Concrete | 5/2016 | 848-857 | Technical Papers |
AbstractThis article presents an experimental programme on reinforced concrete beams retrofitted with steel angles and pre-stressed stainless steel ribbons to increase their flexural strength and ductility. Two different configurations of the steel ribbon were designed, and two companion specimens for each type considered were subjected to a four-point bending test to facilitate a direct comparison in the analysis of the effectiveness of the retrofitting technique. The influence of longitudinal steel angles and transverse stainless steel ribbons is analysed, and the concrete confinement due to stainless steel ribbons examined. The strengthened beams show remarkable increments in flexural strength and ductility with respect to the as-built beam. Moreover, a simple cross-sectional model was adopted to calculate the flexural strength; then sophisticated numerical tools were used to reproduce both the experimental load-displacement curve and crack pattern for each specimen. x | |||||
Confrere, Adeline; Michel, Laurent; Ferrier, Emmanuel; Chanvillard, Gilles | Experimental behaviour and deflection of low-strength concrete beams reinforced with FRP bars | Structural Concrete | 5/2016 | 858-874 | Technical Papers |
AbstractThe primary objective of this new study of fibre-reinforced polymer (FRP)-reinforced concrete (RC) beams is to evaluate the mechanical performance of RC beams made of low strength concrete internally reinforced with FRP. The use of FRP rebars with low compressive strength concrete is desirable in order to avoid the accelerated corrosion processes that could occur with steel rebars. For this purpose, an experimental programme was designed to identify the failure modes and bending behaviour. The experimental results are compared with equations from ACI 440.1R-06, CSA S806-12 and other design codes as well as with other results from a review of the literature. x | |||||
Zhou, Linyun; Liu, Huangin | Response of cracked simply supported concrete beam with moving vehicle load | Structural Concrete | 5/2016 | 875-882 | Technical Papers |
AbstractThe dynamic response of a cracked beam subjected to moving loads has been studied extensively in the past decades. However, very little is known about the dynamic impact factors and crack propagation when vehicles move along the cracked beam. It can be reasonably postulated that a crack extension may occur when the vehicle loads cross the cracked bridge at a high speed. As a result, the dynamic response will be enlarged significantly due to the flexural rigidity reduction induced by cracks, which may result in a dangerous effect on structures. To address this problem, a three-dimensional vehicle-bridge model was developed to investigate the dynamic response of cracked bridges with crack breathing. Crack breathing is simulated at the crack surface using contact elements. The modified crack closure method is adopted to calculate the stress intensity factors. The results showed that the impact factors for the damaged bridge under a moving load could be notably larger than those for the intact bridge, and could exceed the value specified in the AASHTO bridge design code. Meanwhile, crack propagation may occur when the vehicles move along the cracked bridge at a high speed. So, it is very necessary to limit the velocity and transverse position of the vehicles to avoid further damage to the cracked bridge. x | |||||
Maghsoudi, Mohammad; Maghsoudi, Aliakbar; Heshmati, Arash Ali | The monitored and theoretical ultimate moment and ductility of pre-tensioned HSSCC bridge girders | Structural Concrete | 5/2016 | 883-895 | Technical Papers |
AbstractSelf-compacting concrete (SCC) is defined as highly flowable and non-segregating concrete that does not require mechanical vibration during application. Load testing of bridge girders was investigated on full scale T-beams of pre-tensioned high strength self-compacting concrete (PHSSCC). The girders were monitored by fixing different types of sensors at different locations. x | |||||
Aykac, Sabahattin; Kalkan, Ilker; Tankut, Tugrul | Flexural strengthening and repair of RC slabs by adding a new RC layer | Structural Concrete | 5/2016 | 896-909 | Technical Papers |
AbstractThe present paper summarizes the findings of an experimental programme to investigate a strengthening/repair technique through the introduction of a new RC layer to an existing slab. Six RC slabs, composed of twelve cantilever and six interior spans, were tested under monotonic transverse loading. The behaviour of statically determinate cantilever spans and indeterminate interior spans was examined by comparing the test results of these specimens to the results of reference slabs, in which the existing and additional layers were cast monolithically. The influences of recovering the permanent slab deformation before repair and the spacing of the shear connectors between the existing and additional layers were investigated. The tests indicated that recovering the permanent deformations of a slab before repair substantially reduces its rigidity while having little influence on the ultimate load. Furthermore, debonding of the reinforcement was observed to considerably decrease the load capacities and rigidities of the slabs. x | |||||
Inhalt: UnternehmerBrief Bauwirtschaft 5/2016 | UnternehmerBrief Bauwirtschaft | 5/2016 | Inhalt | ||
Schalk, Günther | "Alles ist besser" - nur: für wen? | UnternehmerBrief Bauwirtschaft | 5/2016 | 1 | Editorials |
Ernst & Sohn (Hrsg.) | Gesamtausgabe UBB 5/2016 | UnternehmerBrief Bauwirtschaft | 5/2016 | 1-24 | Gesamtausgabe |
Kurz informiert: UnternehmerBrief Bauwirtschaft 5/2016 | UnternehmerBrief Bauwirtschaft | 5/2016 | 2 | Kurz informiert | |
AbstractBVMB fordert: Reformkommission einsetzen! x | |||||
Nolden, Matthias | Mehr Erfolg im Unternehmen durch Kreativitätstechniken | UnternehmerBrief Bauwirtschaft | 5/2016 | 3-8 | Berichte |
AbstractKreativitätstechniken sind Werkzeuge, die den Prozess der Problemlösung bzw. Ideengenerierung unterstützen. Sie sollen es ermöglichen, in vergleichsweise kurzer Zeit zahlreiche Ideen zu sammeln und dadurch den Unternehmenserfolg zu steigern. Diese Techniken sind auch in kleineren und mittleren Unternehmen zu geringen Kosten einsetzbar. Allerdings wird das Potenzial solcher Techniken gerade in diesen Unternehmen häufig nicht genutzt. Der UBB stellt daher Methoden und ihre Einsatzmöglichkeiten vor, die sich für mittelständische Unternehmen eignen. x |