Artikeldatenbank
Autor(en) | Titel | Zeitschrift | Ausgabe | Seite | Rubrik |
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Teimourtash, Shabnam | Behagliches Raumklima - Wohnen in halboffenen Räumen in ariden Regionen | Bauphysik | 4/2016 | 231-240 | Fachthemen |
KurzfassungDie traditionellen Stadtgebiete der ariden Regionen sind von Innenhöfen geprägt. Sie vermitteln den Eindruck, aus introvertierten Einheiten gebaut zu sein. Das Wohnen in Hofhäusern steht jedoch in enger Verbindung mit dem Außenbereich. Trotz der klimatischen Belastungen gehören offene und halboffene Räume zu den Hauptwohnräumen, wobei die Innenhöfe den Außenbereich dafür bilden. Einer der am weitesten verbreiteten halboffenen Räume der traditionellen Architektur ist der Iwan (wn). Der folgende Artikel befasst sich mit der Frage, wie der Iwan als klimaeffizienter Wohnraum funktioniert hat. Dafür wurden an 30 Fallbeispielen aus vier Städten der ariden Region im Iran Kriterien zur Steigerung der thermischen Behaglichkeit im Iwan untersucht, die jeweilige Position des Iwan im Grundriss analysiert und der Zusammenhang zwischen Windtürmen, Wasserbecken und Hauptwindrichtungen in den warmen Jahreszeiten und deren Einwirkung auf die Raumtemperatur im Iwan studiert. x | |||||
Dworok, Philipp-Martin; Mehra, Schew-Ram | Behaglichkeit - Wechselwirkungen bauphysikalischer Einflüsse | Bauphysik | 1/2018 | 9-18 | Fachthemen |
KurzfassungAufgrund der stringenteren bauphysikalischen Anforderungen an Gebäude gewinnt die Behaglichkeit immer mehr an Bedeutung. Dieser Beitrag zeigt anhand einer Literaturauswertung und eigener Untersuchungsergebnisse den Stand des Wissens bezüglich der Behaglichkeit auf. Insbesondere wird dabei die Wechselwirkung thermischer und akustischer Parameter auf die Behaglichkeit herausgearbeitet. Trotz der uneinheitlichen Untersuchungsrandbedingungen, die teilweise zu widersprüchlichen Ergebnissen führen, ist festzuhalten, dass thermische und akustische Raumparameter einen interagierenden Einfluss auf die Beurteilung der Gesamtbehaglichkeit haben. Deshalb muss jeder Raumparameter, der durch menschliche Wahrnehmung erfasst und subjektiv bewertet wird, bei der Behaglichkeitsbeurteilung in Abhängigkeit der Nutzungsfunktion und Raumsituation berücksichtigt werden. Ganzheitliche Ansätze werden bereits thematisiert sowie diskutiert und sind aufgrund der aufgezeigten Wechselwirkungen zukünftig differenzierter zu betrachten, um die Behaglichkeit trotz der komplexen bauphysikalischen Einflüsse umfassend bewerten zu können. x | |||||
Kimmling, Mathias; Hoffmann, Sabine | Behaglichkeitsmonitoring - flächendeckend und kostengünstig mit der Sensorstation CoMoS | Bauphysik | 2/2019 | 111-119 | Fachthemen |
KurzfassungZur Erfassung von thermischen Umgebungsparametern wurde die Behaglichkeitsmessstation CoMoS (engl. Comfort Monitoring Station) entwickelt. Ziel der Entwicklung war ein kostengünstiges System mit gleichzeitig hoher Messgenauigkeit zum flächendeckenden Einsatz in Gebäuden. Diese Vorgabe wurde durch einen Aufbau erzielt, der auf kompakten, integrierten Sensoren für Lufttemperatur, relative Luftfeuchte, mittels Schwarzkugel gemessener Globe-Temperatur und Luftgeschwindigkeit basiert. x | |||||
Volger, A. H. | Behandlung linearer Gleichungssyteme in der Nähe der Singularität. | Bautechnik | 8/1968 | 262-266 | |
KurzfassungFür lineare Gleichungssysteme und die Inversion von Matrizen wird gezeigt, wie durch Verminderung der Reihenzahl und anschliessendes schrittweises Erweitern numerisch optimale Ergebnisse vor allem in der Nähe der Singularität erreicht werden können. Die Methode kann dazu dienen, in der Nähe der Singularität möglichst allen echten Informationsgehalt nutzbar zu machen. x | |||||
Behandlung von Arbeitslohnspende bei Minijobbern | UnternehmerBrief Bauwirtschaft | 1/2016 | 11-12 | Berichte | |
KurzfassungVereinbaren ein Arbeitgeber und ein Minijobber eine Arbeitslohnspende für Flüchtlinge, stellt sich in der Praxis die Frage, wie diese Spende sozialversicherungsrechtlich und steuerlich zu behandeln ist. Die Antwort kommt von der Minijobzentrale. x | |||||
Seo, Tae-Seok; Kim, Jung-Chul | Behaviour of concrete in a stress continuity region after cracking under restrained drying shrinkage | Structural Concrete | 2/2013 | 131-137 | Technical Papers |
KurzfassungSome studies have investigated the time-dependent characteristic of concrete for predicting stress under restrained shrinkage. However, these studies investigated the shrinkage behaviour of concrete in restrained conditions before cracking, and no study has yet investigated the behaviour of concrete due to restrained shrinkage in the stress continuity region after cracking. Therefore, this study investigates the shrinkage behaviour of concrete in the stress continuity region after cracking in uniaxial restrained specimens and analyses the restrained tensile stress of concrete in this region by way of a bond analysis. The results show that the effective tensile Young's modulus considering tensile creep is approx. 22-26% of the static modulus of elasticity. Moreover, the analytical results of the restrained tensile stress of concrete considering the effective tensile Young's modulus were in accordance with the experimental results. x | |||||
Beben, D.; Manko, Z. | Behaviour of corrugated plate culvert under backfilling loads | Steel Construction | 3/2009 | 188-202 | Articles |
KurzfassungThis paper is presents the results and conclusions of the field tests conducted on a backfilled shell structure made of Super Cor SC-56B corrugated steel plates in a road bridge located in Gimån, Sweden. The paper also presents the application of the FLAC (Fast Lagrangian Analysis of Continua) program, based on the finite differences method (FDM), for determining the behaviour of soil-steel bridge structures during backfilling. The assumptions of a computational 2D model of the shell structure with a non-linear “interface” layer are described. The method based on this computational model may be used with considerable success in the design calculations for this specific type of structures. The conclusions drawn from the tests can be helpful when assessing the behaviour of this type of the soil-steel bridge structure under the load of backfilling. Considering the increased application of this type of structure for small and medium-sized road and rail bridges, the conclusions drawn from the analysis conducted can be generalized to cover a whole class of such structural solutions. x | |||||
Kolstein, Henk; Li, Jingbin; Koper, Axel; Gard, Wolfgang; Nijgh, Martin; Veljkovic, Milan | Behaviour of double shear connections with injection bolts | Steel Construction | 4/2017 | 287-294 | Articles |
KurzfassungThe RFCS project SIROCO (2014-17) included research on the further development and optimization of double shear connections with injection bolts to achieve slip- and creep-resistant bolted connections considering various influencing parameters. The type of resin, the curing condition of the resin, the geometrical and mechanical characteristics of the connection and the type of loading were studied. Results showed, for example, that of the five epoxy resins investigated, only RenGel SW404 + HY2404 (Araldite) fulfils the requirements given in Eurocode 3. A bearing stress of 175 MPa is safely allowable in the long-term without exceeding imposed deformation limits. x | |||||
Stanislaw Urban, Tadeusz; Goldyn, Michal Marcin | Behaviour of eccentrically loaded high-strength concrete columns intersected by lower-strength concrete slabs | Structural Concrete | 4/2015 | 480-495 | Technical Papers |
KurzfassungThis paper presents the results of experimental investigations of high-strength concrete edge and corner columns intersected by concrete slabs. The effect of the intersection by weaker slab concrete on the load-carrying capacities of reinforced concrete columns is investigated. The only parameter considered was the location of the column with respect to the edge of the slab. It is stated that providing a small slab overhang beyond the column edge makes it possible to increase the actual strength of the joint concrete significantly. The results of the authors' research clearly demonstrate that providing a sufficiently large slab overhang allows the designer to treat edge and corner column-slab connection joints in the same way as internal joints. Existing code provisions concerning strength of concrete in edge and corner column-slab connection joints are in some cases too conservative and require clarification. x | |||||
Korte, Sara; Boel, Veerle; De Corte, Wouter; De Schutter, Geert | Behaviour of fatigue loaded self-compacting concrete compared to vibrated concrete | Structural Concrete | 4/2014 | 575-589 | Technical Papers |
KurzfassungFatigue loading and its sometimes inevitable fatigue failure are common in many civil engineering construction projects. The behaviour of vibrated concrete (VC) under this type of loading is well understood. However, the fracture and fatigue resistance of self-compacting concrete (SCC) is poorly documented in literature. Considering the substantially different composition of the two concrete types (VC and SCC), it is uncertain whether their mechanical properties are similar or not. This paper describes the results of a series of destructive static and cyclic four-point bending tests on inverted T-shaped reinforced concrete beams, made from VC and SCC in equal quantities and of equal compressive strength. A comparison of the two concrete types is made, based on deflection, strain, crack width evolution and failure mechanism. The experiments prove that these mechanical properties of VC and SCC, subjected to a fatigue load, in some cases relate differently from a static loading process. Furthermore, the results reveal a faster concrete strain and crack width development for SCC during the fatigue tests. Regarding the number of cycles to failure, the applied load level is crucial. x | |||||
Aguiar, Eduardo Aurélio Barros; Bellucio, Ellen Kellen; El Debs, Mounir Khalil | Behaviour of grouted dowels used in precast concrete connections | Structural Concrete | 2/2012 | 84-94 | Articles |
KurzfassungThis research deals with the behaviour of grouted dowels used in beam-to-column connections in precast concrete structures. The research focuses primarily on the theoretical and experimental analysis of the resistance mechanism of the dowels. The experimental programme included 15 models for analysing the following variations in dowel parameters: a) dowel diameters of 16, 20 and 25 mm, b) dowel inclinations of 0° (i.e. perpendicular to the interface), 45° and 60°, c) compressive strength of classes C35 and C50 for the concrete adjacent to the dowels, and d) the absence or presence of compressive loads normal to the interface. The experimental results indicate that the ultimate capacity and shear stiffness of the inclined dowels are significantly higher than those of the perpendicular dowels. Based on these results, an analytical model is proposed that considers the influence of the parameters studied regarding the capacity of the dowel. x | |||||
Jordão, Sandra; Pinho, Marco; Martin, João Pedro; Santiago, Aldina; Neves, LuÃs Costa | Behaviour of laminated glass beams reinforced with pre-stressed cables | Steel Construction | 3/2014 | 204-207 | Article |
KurzfassungStructural glass corresponds to an innovative material with extraordinary aesthetical and architectonic potential that has undergone significant technological advances in recent years, yielding it stronger and safer. For this reason, the use of structural glass has increased considerably in the last decade and is now an unavoidable presence in most of recent reference buildings. x | |||||
Ebert, Andreas; Dörre, Maik; Glienke, Ralf | Behaviour of lockbolts in slip-resistant connections for steel structures | Steel Construction | 4/2017 | 295-309 | Articles |
KurzfassungHV bolts are often used for safe and durable connections in steel structures. However, this well-known and established bolting system has some disadvantages. Those include the scattering of the initial preload by the torque-controlled tightening method and the risk of self-loosening during fatigue loads due to lateral displacement of the components in connections with high loads. In this respect, the lockbolt technology has some advantages regarding the initial preload and loss of preload; both will be discussed in detail in this paper. The technology was invented in the 1940s and is mainly used in automotive, aviation, truck, trailer, rail, bus, agriculture, mining and military applications. Its use in structural steelwork, and especially for slip-resistant connections, has been mainly made possible through individual experimental investigations by users of the technology. Some applications call for its use in slip-resistant connections according to EN 1090-2 and Eurocode 3, e.g. the wind industry for new tower concepts with higher hub heights, and steel girder bridges. These connections can be subjected to fatigue and/or significant load reversal. The load-bearing capacity (or slip resistance) of a slip-resistant connection is mainly determined by the level of preload in the bolt and the coating system applied to the faying surfaces. However, the preload is determined by the type of bolt, and lockbolts can be used as an alternative bolting system. This paper describes a comparative study of HV bolts and lockbolts regarding their use in slip-resistant connections for steel structures. The design and execution of lockbolts will be presented. Investigations will be presented which compare HV bolts and lockbolts regarding the assembly preload, the slip resistance by performing slip load tests and the long-term behaviour with respect to loss of preload for maintenance-free connections. Furthermore, there is a discussion of the results of an online monitoring system for measuring the preload in HV bolts and Bobtail lockbolts in an alternative tower for wind turbines with the use of slip-resistant connections. 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 |
KurzfassungThis 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 | |||||
Chin, Siew Choo; Shafiq, Nasir; Nuruddin, Muhd Fadhil | Behaviour of RC beams with CFRP-strengthened openings | Structural Concrete | 1/2016 | 32-43 | Technical Papers |
KurzfassungA detailed investigation was conducted to study the behaviour of reinforced concrete (RC) beams with large openings strengthened by externally bonded carbon fibre-reinforced polymer (CFRP) laminates. A total of six simply supported beams consisting of two solid beams and four beams with openings were cast and tested under four-point bending. Each beam had a cross-section of 120 × 300 mm and length of 2000 mm. Each beam had a large opening placed symmetrically at mid-span. Test parameters included the opening shape and size as well as the strengthening configuration for the CFRP laminates. The study was conducted by way of both experimental testing and finite element analysis. The experimental results show that including a large opening at mid-span reduces the beam capacity to about 50 %. In the experimental results, strength gain due to strengthening with CFRP laminates was in the range 80-90 %. The finite element and experimental results were compared. x | |||||
López-López, Andrés; Tomás, Antonio; Sánchez-Olivares, Gregorio | Behaviour of reinforced concrete rectangular sections based on tests complying with seismic construction requirements | Structural Concrete | 4/2016 | 656-667 | Technical Papers |
KurzfassungThe prediction of the seismic behaviour of reinforced concrete elements using numerical models has become a field of growing interest in recent years due to the importance of the effects induced by seismic loads applied to reinforced concrete structures. The simulation of the hysteretic behaviour of the plastic hinges generated in the structure when the seismic load acts requires the use of models that are able to describe the sectional behaviour of structural members. Thus, the main objective of the present paper is the adjustment of several empirical expressions that reduce the computational time needed to simulate the yield and ultimate behaviour of a given reinforced concrete rectangular section under either monotonic or cyclic loading. The expressions are calibrated with a selection of tests, taken from a published database of more than 1000 tests, according to the criterion that the selected specimens comply with the seismic construction requirements of the main international building codes (EC-2, EC-8 and ACI-318). Owing to their robustness and the acceptable computation time for low-dimensional problems, genetic algorithms are used for this calibration. The equations proposed can be employed by structural engineers for the design and analysis of actual structural elements used in ordinary reinforced concrete buildings located in seismic areas, and provide more accurate results than other expressions. x | |||||
Barros dos Santos, Gabriel; de Miranda Batista, Eduardo; de Araújo, Afonso Henrique Mascarenhas | Behaviour of RHS beam-to-column bolted steel connections | Steel Construction | 4/2016 | 296-304 | Articles |
KurzfassungThe connection concept is a key point in the design of steel structures which affects fabrication, erection procedures and the final costs. Welding processes have been extensively used for tubular trussed girders by combining shop welding with bolted flange solutions to facilitate straightforward connection procedures during erection. The present research addresses the behaviour of innovative beam-to-column bolted connections for steel rectangular hollow sections (RHS) which combine simplicity in fabrication and erection, favourable aesthetics for the case of visible structures and structural effectiveness. Four cruciform prototypes were tested under a static non-reversible bending moment with different bolted conditions: i) non-friction and ii) friction connection. The experimental results show that the proposed geometry with friction connections is able to develop a rigid elastic moment-rotation response up to usual loading conditions. x | |||||
Gálvez, Francisco; Atienza, Jose Miguel; Elices, Manuel | Behaviour of steel prestressing wires under extreme conditions of strain rate and temperature | Structural Concrete | 4/2011 | 255-261 | Articles |
KurzfassungThe purpose of this paper is to provide information on the behaviour of steel prestressing wires under likely conditions that could be expected during a fire or impact loads. Four loadings were investigated: a) the influence of strain rate - from 10-3 to 600 s-1 - at room temperature, b) the influence of temperature - from 24 to 600 °C - at low strain rate, c) the influence of the joint effect of strain rate and temperature, and d) damage after three plausible fire scenarios. x | |||||
Behaviour of Steel Structures in Seismic Areas - Sixth International Conference | Steel Construction | 2/2009 | 147-148 | Announcements | |
Ozbolt, Ana; Kuhlmann, Ulrike; Henriques, José; da Silva, LuÃs Simões | Behaviour of steel-to-concrete joints | Steel Construction | 3/2012 | 145-150 | Articles |
KurzfassungThis paper presents innovative solutions for connecting steel and composite beams to structural reinforced concrete walls, as developed within the RFCS research project “InFaSo”. Two types of joints were studied: pinned and moment-resistant. The evaluation of the behaviour of the joints was performed experimentally and complemented by the development of analytical component-based models. The comparison of the results revealed good agreement between models and experiments. The joints analysed were shown to be competitive solutions taking into account their structural performance, simplicity of modelling and execution. x | |||||
Henriques, José; da Silva, LuÃs Simões; Ozbolt, Ana; Kuhlmann, Ulrike; i ka, Ji Ã; Wald, Franti ek | Behaviour of steel-to-concrete joints - moment resisting joint of a composite beam to reinforced concrete wall | Steel Construction | 3/2011 | 161-165 | Articles |
KurzfassungThe studied joint configuration is illustrated in Fig. 1. Two different transfer areas may be distinguished. The upper area consists of a reinforced concrete slab where the longitudinal reinforcement is anchored in the reinforced concrete wall. The wall and the slab were concreted at different times and therefore, no shear is assumed to be transferred between these members. Any friction is neglected. Thus, only tension is transferred through this part of the joint. At the bottom area, the steel beam sits in a steel bracket welded to an anchor plate which is fastened the reinforced concrete wall. The fixation between anchor plate and wall is achieved by headed studs welded to the plate. On the outside of the steel bracket, a plate is welded creating a “nose” which avoids the slip of the beam out of the steel bracket. The end-plate of the steel beam is used for this propose. This end-plate transmits the shear load to the steel bracket. Finally, compression is transferred to the reinforced concrete wall using a contact plate between end-plate and anchor plate. The flux of loads is schematically represented in Fig. 2 for a hogging bending moment. x | |||||
Henry, Richard; Ingham, Jason | Behaviour of tilt-up precast concrete buildings during the 2010/2011 Christchurch earthquakes | Structural Concrete | 4/2011 | 234-240 | Articles |
KurzfassungThe Christchurch region of New Zealand experienced a series of major earthquakes and aftershocks between September 2010 and June 2011 which caused severe damage to the city's infrastructure. The performance of tilt-up precast concrete buildings was investigated and initial observations are presented here. In general, tilt-up buildings performed well during all three major earthquakes, with mostly only minor, repairable damage occurring. For the in-plane loading direction, both loadbearing and cladding panels behaved exceptionally well, with no significant damage or failure observed in panels and their connections. A limited number of connection failures occurred due to large out-of-plane panel inertia forces. In several buildings, the connections between the panel and the internal structural frame appeared to be the weakest link, lacking in both strength and ductility. This weakness in the out-of-plane load path should be prevented in future designs. x | |||||
Beheizung von Neubauwohnungen in der Bundesrepublik Deutschland | Bauphysik | 5/1990 | 157 | Aktuelles | |
Jäckels, W.; Patitz, R. | Behelfsbrücke "Lange Brücke" in Berlin-Köpenick. | Stahlbau | 12/1996 | 531-535 | Fachthemen |
Hornecker, G.; Baumgärtner, R. | Behindertengerechte Geh- und Radwegüberführung "Gottlieberstraße" in Konstanz - Entwurf und Ausführung | Stahlbau | 2/2003 | 71-78 | Fachthemen |
KurzfassungMit einer räumlichen Stahlfachwerk-Konstruktion wurde in einem sensiblen innerstädtischen Umfeld in Konstanz eine behindertengerechte Geh- und Radwegverbindung realisiert. Die asymmetrische Brückenlösung paßt zu dem Umfeld. Die Gestaltung, insbesondere der konkave Grundriß, entspringt der sich natürlich ergebenden örtlichen Situation. Im folgenden Aufsatz wird auf Fragen der Entwurfsentstehung, der Gründungsproblematik, der Konstruktion und Statik des Tragwerks und der Herstellung eingegangen. x |