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Steel fiber reinforced geopolymer concrete (SFRGC) shows excellent mechanical properties comparable to steel fiber reinforced concrete. However, research on the durability of SFRGC is scarce. This paper presents the carbonation performances of SFRGC, including the carbonation depth and strength variation during carbonation. The results show that the permeability and carbonation depth of SFRGC are close to those of plain geopolymer concrete (GC). Their carbonation depths are much deeper than those of cement concrete because of the lower alkali content of the geopolymer matrix. Carbonation hardly influences the final flexural strength of plain GC, but the flexural strength of SFRGC declines significantly during carbonation because of the decrease in steel fiber-geopolymer matrix bond strength. The scanning electron microscope results show that the failure mode in uncarbonated SFRGC specimens is fiber rupture, while in carbonated SFRGC specimens, fiber pullout is the failure mode. These findings suggest that using SFRGC in the atmosphere is not recommended. [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Changes in the Canadian steel industry warrant a review of the steel resistance factor in CSA Standard S16 (formerly S16.1) "Limit states design of steel structures", originally calibrated in the landmark study by Kennedy and Gad Aly in 1980. This paper presents statistical parameters for the bending, compression, and tension resistances of W, WWF, and HSS components produced since 1999 that have been derived from geometric and material properties presented in a companion paper. The resistance factor for steel was recalibrated for the live and dead load combination in the 1995 National Building Code of Canada. A resistance factor of 0.95 is suitable for laterally supported beams, stocky columns, and tension members failing by yield of the gross section, whereas the current value of 0.90 is appropriate for intermediate columns and tension members failing by fracture of the net section. [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The steel-free deck slab developed in Canada used straps as a confinement system and relied on the stiffness of this confinement system rather than its strength. In this paper, a new approach, using the strength of a confinement system comprising unbonded prestressed bars, was investigated. In addition, the effect of the concrete strength and the steel ratio of the confinement system was examined. Seven large-scale one-way steel-free deck slabs were built using normal- and high-strength concrete, prestressed to different levels, and statically tested up to failure. The overall behaviour of the slabs was similar to that of slabs confined by straps. Cracking strength was not considerably enhanced. The slabs failed in punching shear mode with high loads. The new approach was not able to overcome the problem of the longitudinal crack, which developed in the tested slabs and reportedly appeared in all the steel-free slabs built or tested previously in Canada. Prestressing had a definite effect, however, on delaying the occurrence of this longitudinal crack, thereby enhancing serviceability. The paper recommends that the serviceability limit state of the steel-free slabs would be better assessed by the occurrence of the longitudinal crack, even though the ultimate capacity of the slabs is high.Key words: arch action, cracking, external prestressing, high-strength concrete, punching shear, steel-free deck slab.Les tabliers de pont sans acier développés au Canada utilisaient des courroies métalliques de renfort comme système de confinement et comptaient sur la rigidité de ces courroies plutôt que sur leur résistance. Dans cet article, une nouvelle approche, utilisant la résistance d'un système de confinement de barres précontraintes non liées, a été étudiée. De plus, l'effet de la résistance du béton et le rapport d'acier du système de confinement a été examiné. Sept dalles sans acier de grande taille à une direction ont été construites en utilisant du béton à résistance normale et à haute résistance, soumises à différents niveaux de précontrainte, et testées statiquement jusqu'à la rupture. La réponse d'ensemble des dalles était similaire à celle des dalles confinées par des courroies. La résistance à la fissuration n'a pas été grandement améliorée. Les dalles ont cédé par poinçonnement sous de hautes charges. La nouvelle approche n'a pas été capable de surmonter le problème des fissures longitudinales qui se sont développées dans les dalles testées et qui ont été reportées pour toutes les dalles sans acier construites ou testées auparavant au Canada. Cependant, la précontrainte a eu un effet certain en retardant l'apparition de cette fissure longitudinale, ce qui signifie une meilleure vie de service. L'article a recommandé que l'état limite de service des dalles sans acier pourrait être mieux évalué avec l'apparition de fissures longitudinales, même si la capacité ultime des dalles est grande.Mots clés : action de cintrage, fissuration, précontrainte externe, béton à haute résistance, poinçonnement, tablier de pont sans acier.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Changes in the Canadian steel industry warrant a review of the steel resistance factor in CSA Standard S16 (formerly S16.1) "Limit states design of steel structures", originally calibrated in the landmark study by Kennedy and Gad Aly in 1980. This paper summarizes data collected in 1999 and 2000 to determine statistical descriptions of geometric and material properties of rolled W, WWF, and HSS shapes that represent current steel production. Distinct sub-populations have been encountered within a single grade of WWF or HSS material. The geometric properties of rolled W, WWF, and HSS shapes produced to CSA Standard G40.20 have not significantly changed from the values reported by Kennedy and Gad Aly. The statistical parameters for yield strength have improved significantly for HSS shapes, improved slightly for WWF shapes, and worsened slightly for rolled W shapes. Complete summaries of the statistical data are presented. In a companion paper, these data are used to review the resistance factor for steel. [ABSTRACT FROM AUTHOR]

This paper covers the verification tests carried out at the Royal Military College of Canada on wood–steel–wood and wood–steel bolted connections. Thirty groups of specimens were tested. Specimen configurations were selected in such a way to include fundamental brittle and ductile failure mode cases. Comparisons between experimental results and predictions from proposed equations developed from steel–wood–steel bolted connections are given. Proposed design equations were found to provide better predictions of the ultimate loads than current CSA Standard O86.1 design procedures especially for bearing. However, row shear-out predictions seem to overestimate the strength. An adjustment using the reduced (effective) thickness concept is therefore proposed. Experimental observations on specimens that failed in row shear-out indicated that shear failure occurred over a reduced thickness. Stress analysis confirms findings on the reduced thickness. The research program is described in this paper along with the results and the proposed design equations for wood–steel–wood and wood–steel bolted connections loaded parallel-to-grain.Key words: wood–steel–wood, wood–steel, bolt, connection, strength, failure, design, thickness.Cet article couvre les tests de vérification effectués au Collège militaire royal du Canada sur des connexions boulonnées bois–acier–bois et bois–acier. Trente groupes de spécimens ont été testés. La configuration des spécimens a été choisie de sorte que les modes fondamentaux de rupture fragile et ductile soient représentés. Des comparaisons entre les résultats expérimentaux et les prédictions provenant des équations développées pour les connexions boulonnées acier–bois–acier sont données. Les équations de conception proposées se sont avérées meilleures que les procédures de conception de la norme CSA 086.1 actuelle pour la prédiction de la charge ultime, spécialement pour les appuis. Cependant, les prédictions du cisaillement en rangée semblent surestimer la résistance. Un ajustement utilisant le concept de l'épaisseur réduite (efficace) est donc proposé. Les observations expérimentales des spécimens qui ont cédés en cisaillement en rangée démontrent que les ruptures en cisaillement surviennent où l'épaisseur est réduite. Des analyses de contraites confirment les découvertes concernant l'épaisseur réduite. Le programme de recherche est décrit dans cet article avec les résultats et les équations de conception proposées pour des connexions boulonnées bois–acier–bois et bois–acier chargées parallèlement au grain.Mots clés : bois–acier–bois, bois–acier, boulon, connexion, résistance, rupture, conception, épaisseur.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Compression members in steel bridges designed before 1960 may be deficient according to current design code requirements and so require strengthening. This paper explores the response of steel wide-flange columns reinforced with new steel flange cover plates, accounting for: residual and locked-in dead-load stresses; different yield strengths of the original W shape and the new cover plates; initial out-of-straightness; and load eccentricity at the member ends. A refined numerical analysis model is formulated and validated that computes the compressive resistance from principles of equilibrium, compatibility, and force-deformation relationships. Parametric studies conducted indicate that the capacity of the reinforced column is relatively insensitive to the magnitude of the locked-in dead-load stress in the original member, and that the strong axis capacity is insensitive to the magnitude of the residual stresses in the original member. A preliminary approach for designing strengthening for these members is presented and illustrated with an example calculation. Les éléments en compression des ponts en acier conçus avant 1960 peuvent être inadéquats selon les exigences du code de conception actuel; ils auraient donc besoin d’être renforcés. Cet article examine la réponse des colonnes en poutres d’acier à brides, renforcées de nouvelles plaques d’acier de recouvrement, tenant compte des contraintes statiques résiduelles, des contraintes permanentes, des différentes limites d’élasticité du profilé original en forme de W et les nouvelles plaques de recouvrement des brides, la non-linéarité initiale et l’excentricité des charges aux extrémités des éléments. Un modèle d’analyse numérique perfectionné est préparé et validé; il calcule la résistance à la compression à partir des principes d’équilibre, de compatibilité et de relations contrainte-déformation. Des études paramétriques effectuées indiquent que la capacité de la colonne renforcée est relativement insensible à l’amplitude de la charge statique permanente dans l’élément original, et que la capacité de l’axe majeur est insensible à l’amplitude de la charge résiduelle dans l’élément original. Une approche préliminaire à la conception du renforcement pour ces éléments est présentée et illustrée par un exemple de calcul. [ABSTRACT FROM AUTHOR]

This paper describes an experimental study on double-angle shear connections with a narrow outstanding leg width from 31 to 37 mm. When connection angles are welded to a supporting column with a face width less than 152 mm, a common practice is either to weld the angles to the column by flare bevel groove welds or shorten the outstanding legs to accommodate fillet welds. This practice reduces the rotational capacity of the connections; and therefore confirmation of this practice is required. Three groups, comprising 12 full-scale connection specimens, were tested. Each group consisted of four specimens having three, four, five, and six bolts, respectively. Group A used 9.5 mm thick angles and fillet welds, group B used 6.4 mm thick angles and fillet welds, and group C used 9.5 mm thick angles and flare bevel groove welds. The test results demonstrated that both rotational and shear capacities of the connections are satisfactory when either of the two details are used. Cet article décrit une étude expérimentale des assemblages de cisaillement à deux cornières avec un membre étroit non relié d’une largeur de 31 à 37 mm. Lorsque les cornières de raccordement sont soudées à une colonne de soutènement dont la largeur est inférieure à 152 mm; une pratique courante est de souder les cornières à la colonne en utilisant des soudures sur chanfrein évasées ou en raccourcissant les membres non reliés pour tenir compte des soudures d’angle. Cette pratique réduit la capacité rotationnelle des assemblages. Il faut donc la valider. Trois groupes comprenant douze échantillons d’assemblage à pleine échelle ont été mis à l’épreuve. Chaque groupe comportait quatre échantillons ayant respectivement trois, quatre, cinq ou six boulons. Le groupe A utilisant des cornières de 9,5 mm et des soudures d’angle; le groupe B utilisait des cornières de 6,4 mm et des soudures d’angle, alors que le groupe C utilisait des cornières de 9,5 mm d’épaisseur et des soudures sur chanfrein. Les résultats des essais démontrent que les capacités en rotation et au cisaillement des assemblages sont satisfaisantes lorsque l’un ou l’autre des détails est utilisé. [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effective length factors for steel solid round diagonals in all-welded communication towers are investigated in this paper to provide experimental basis for the relevant clauses in CSA Standard S37-01. The results of a total of 31 all-welded lattice tower specimens with three types of cross-braced diagonals are presented. The failure loads for these members were determined from the maximum axial strains measured during the tests. The effective length factors were then back-calculated from the experimental failure loads using the compressive resistance formulas. The test results showed that even the significantly lower effective length factors specified in CSA S37-01, compared to CSA S37-94, are still conservative.Key words: all-welded towers, communication towers, cross-bracing, effective length factors, solid round steel diagonals.Les facteurs de longueur effective des diagonales circulaires en acier solide des tours de communication à joints soudés sont étudiés dans cet article afin de fournir une base expérimentale aux clauses pertinentes de la norme CSA S37-01. Les résultats provenant de trente et un échantillons de tours en treillis à joints soudés avec trois types de contreventement sont présentés. Les charges de rupture de ces membres ont été déterminées à partir des déformations axiales maximales mesurées durant les tests. Les facteurs de longueur effective ont ensuite été calculés à partir des charges de ruptures expérimentales en utilisant les formules de résistance en compression. Les résultats démontrent que même les plus petits facteurs de longueur effective précisés dans le CSA S37-01, comparés au CSA S37-94, sont conservateurs.Mots clés : tours à joints soudés, tours de communication, contreventement, facteurs de longueur effective, diagonales circulaires en acier solide.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Composite beams with corrugated steel webs represent a new innovative system which has emerged in the past decade for short and medium span bridges. The new system usually combines the usage of corrugated steel plates as webs and reinforced/prestressed concrete slabs as flanges for plate or box girders. Bridges that have been recently built with this hybrid system are outlined in this paper, which focuses on the advantages of using corrugated steel webs as opposed to traditional flat webs. The flexural behaviour and bearing resistance of girders with corrugated steel webs is briefly discussed. The flanges of the new system solely provide the flexural strength of the beam with no contribution from the corrugated web. On the other hand, the corrugated web provides the shear capacity of the system. Thus, the shear behaviour of girders with corrugated webs is explicitly discussed focusing on the different failure and (or) buckling modes that affect the design of the corrugated steel web plates. Design charts for such webs are constructed based on the different interaction equations of failure. The torsion-warping behaviour of composite box girders with corrugated steel webs is also discussed.Key words: bridges, composite beams, corrugated steel webs, global buckling mode, interactive buckling, local buckling.Les poutres composées avec des âmes d'acier ondulées représentent un nouveau système innovateur, qui a émergé dans la dernière décennie pour des ponts de courte et moyenne portée. En général, ce nouveau système combine l'utilisation de plaques d'acier ondulées en tant qu'âmes avec des dalles de béton armé/précontraint en tant qu'ailes afin de former des poutres de type plaque ou boîte. Des ponts, qui ont été récemment construits selon ce système hybride, sont mis en lumière dans cet article, qui se concentre sur les avantages d'utiliser des âmes d'acier ondulées par opposition à des âmes traditionnelles plates. Le comportement en flexion et la résistance au chargement des poutres sont discutés brièvement. Seules les ailes de ce nouveau système fournissent la résistance en flexion de la poutre, puisqu'il n'y a pas de contribution provenant de l'âme. Cependant, l'âme ondulée fournit la capacité contre le cisaillement du système. Donc, le comportement en cisaillement de poutres avec des âmes ondulées est discuté explicitement, avec une attention particulière donnée sur les différents modes de défaillance et/ou flambage qui affectent la conception des plaques d'âmes d'acier ondulées. Des graphiques de conception pour de telles âmes sont construits sur la base des différentes équations d'interaction pour la défaillance. Le comportement en torsion-gauchissement de poutres de type boîte avec des âmes d'acier ondulées est aussi discuté.Mots clés : ponts, poutres composées, âmes d'acier ondulées, mode de flambage global, flambage interactif, flambage local.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

This paper describes the seismic behaviour of chevron steel braced frames for 2-, 4-, 8-, and 12-storey steel building structures. Two different design approaches were considered: one that corresponds to current CSA-S16.1 seismic provisions for braced frames with nominal ductility with an R factor of 2.0, and one in which the beams are sized to develop a fraction of the yield tension capacity of the bracing members. In this second approach, an R factor of 3.0 was used for determining the seismic loads and chevron bracing with stronger beams capable of developing 100%, 80%, and 60% of the brace yield load were examined. The results show that current S16.1 provisions for chevron braced frames may lead to systems that are prone to dynamic instability for 4-storey and taller structures. Chevron bracing with stronger beams exhibits a more stable inelastic response and can be used for structures up to 8 storeys in height. For 2- and 4-storey buildings, chevron braced frames with beams designed to develop only 60% of the brace yield resistance can be used. The analyses also show that the force demand in brace connections, beams, and columns as determined from capacity design provisions agree well with that anticipated under strong ground motions.Key words: earthquakes, seismic design, steel, structures, braced frames, bracing members, beams, columns, connections.Cet article décrit le comportement sismique de contreventements en treillis avec diagonales en chevron utilisés dans la charpente d'acier de bâtiments de 2, 4, 8 et 12 étages. Deux approches de conception ont été considérées : l'une qui suit les dispositions actuelles de la norme CSA S16.1 pour les contreventements à ductilité nominale et l'autre où les poutres sont conçues pour résister aux efforts engendrés lorsque l'effort dans la diagonale tendue atteint une fraction de sa limite élastique. Pour la seconde méthode, on a considéré un coefficient R égal à 3,0 pour le calcul des charges sismiques et on a étudié des contreventements dont les poutres pouvaient reprendre des efforts correspondant à un effort dans les diagonales tendues égal à 100%, 80% et 60% de leur limite élastique. Les résultats montrent que les contreventements de 4 étages et plus peuvent subir de grandes déformations latérales et être sujets à une instabilité dynamique lorsque conçus selon la norme S16.1 actuelle. Les contreventements avec poutres pouvant soutenir la plastification des diagonales tendues ont un comportement plus stable et peuvent être utilisés dans des structures jusqu'à 8 étages. Pour des bâtiments de 2 et 4 étages, on peut utiliser des poutres conçues pour un effort dans les diagonales tendues égal à 60% de leur résistance plastique. Les analyses dynamiques démontrent également que les efforts dans les assemblages des diagonales, dans les poutres et dans les poteaux tels, qu'obtenus d'un calcul par capacité, correspondent bien aux efforts que l'on peut anticiper lors d'un séisme important.Mots clés : séismes, conception parasismique, acier, structures, contreventements en treillis, diagonales, poutres, poteaux, assemblages. [ABSTRACT FROM AUTHOR]

The article presents the proposal to evaluate the torsional behaviour of steel members and questions the correctness of the proposed design equation, as they violate the principles of structural mechanics under the Canadian steel standards (CSA S16). It presents several interaction equations used by the author as a basis to examine the strength of columns under compression, biaxial bending and torsion. The elastic beam theory served as the basis of all the equations and warping stress distributions.

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Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents an analysis method in which both the nonlinear rotational behaviour of beam-to-column connections and second-order (P-Δ and P-δ) effects of beam-column members are explicitly taken into account. By adopting the concept of an end-fixity factor, the proposed method is comprehensive regardless of the end rotational conditions of beam-column members and applies to frames with any combination of pinned, semirigid and rigid beam-to-column connections. In addition, the end-fixity factor simplifies the analysis procedure for semirigid frames. More importantly, the end-fixity factor may be valuable to the design of such structures because it provides a physical interpretation of the extent of rigidity available in a connection. Thus, it provides a convenient way for designers to compare the structural responses of a semirigid member to that of a rigid one. Examples are presented to demonstrate the validity and efficiency of the proposed approach. With only minor modifications, the proposed method is readily implemented in existing rigid frame analysis and design computer programs.Key words: steel frame, semirigid connection, second-order analysis, P-Δ effect.Cet article présente une méthode d'analyse dans laquelle le comportement en rotation de la connexion poutre-colonne et les effets de second ordre (P-Δ et P-δ) des membres poutre-colonne sont explicitement considérés. En adoptant le concept d'un facteur de stabilité à l'extrémité, la méthode proposée est complète peu importe les conditions en rotation de l'extrémité des membres poutre-colonne et s'applique à des cadres avec n'importe quelle combinaison de connexions poutre-colonne à jointure, semi-rigides ou rigides. De plus, le facteur de stabilité à l'extrémité simplifie la procédure d'analyse des cadres semi-rigides. Plus important encore, le facteur de stabilité à l'extrémité peut être de valeur pour la conception de telles structures, car il fournit une interprétation physique de l'étendue de la rigidité disponible dans une connexion. Donc, il fournit aux concepteurs un moyen commode pour comparer la réponse structurale d'un membre semi-rigide à celle d'un membre rigide. Des exemples sont présentées afin de démontrer la validité et l'efficacité de l'approche proposée. Avec seulement des modifications mineures, la méthode proposée s'implante aisément dans les programmes informatiques d'analyse et de conception de cadres rigides existants.Mots clés : cadre d'acier, connexion semi-rigide, analyse de second ordre, effet P-Δ.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A simple alternative equation for the calculation of the strength of laterally unbraced structural steel beams is presented herein. This equation uses a format similar to the present steel column design curve in the Canadian structural steel design standard, CAN/CSA-S16-09, and is proposed as a replacement for the existing three part curve for beam strength by a one part equation with a continuous derivative. A reliability analysis of the new equation indicates that the equation provides safety levels very close to those of the current formula for classes 1 and 2 rolled sections. It also provides the desired level of safety for welded beams, whereas the current equations tend to over-estimate their strength. The alternative equation also provides adequate safety for class 3 beams. The concept of maximum unbraced length for braced beam design (Lu) is revisited herein and a simple calculation for this length is also proposed. Une simple équation de remplacement pour le calcul de la résistance des poutres structurales en acier non entretoisées est présentée. Cette équation utilise un format similaire à la courbe de conception actuelle des colonnes en acier dans la norme CAN/CSA-S16-09 Règles de calcul des charpentes en acier; il est proposé de remplacer la courbe actuelle en trois parties sur la résistance des poutres par une équation à une partie contenant une dérivée continue. L'analyse de la fiabilité de la nouvelle équation montre que l'équation fournit des niveaux de sécurité très près de ceux de la formule actuelle pour les sections laminées de classes 1 et 2. L'analyse fournit également le niveau de sécurité désiré pour les poutres soudées, alors que les équations actuelles ont tendance à surestimer leur résistance. L'équation de remplacement fournit également un niveau de sécurité adéquat pour les poutres de classe 3. Le concept de la longueur maximale non entretoisée pour la conception des poutres entretoisées (Lu) est revu et un simple calcul de cette longueur est aussi proposé. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main focus of this investigation is directed toward the examination of crack-spacing expressions suitable for offshore concrete structure applications. Offshore structures are unique structures that are constantly exposed to harsh environmental conditions, including exposure to seawater and sea spray. The splash zone of an offshore structure is the section of the platform that is the most exposed to both a harsh marine environment and seawater. The design of offshore structures is controlled by mandatory design codes to ensure structural safety and integrity. Most of the available expressions for crack spacing were developed for building structures using normal-strength concrete and normal concrete cover. However, offshore structures are built using high-strength concrete with a thick concrete cover. Very little information is published on the crack analysis of high-strength concrete with a thick concrete cover for offshore applications. An experimental testing program was designed to examine the effects of concrete cover and the bar spacing of normal- and high-strength concrete on crack spacing. The different code expressions are evaluated with respect to the experimental results. Cette étude porte principalement sur l’examen des équations de l’espacement des fissures pour les structures en béton en mer. Les constructions en mer sont des structures uniques qui sont constamment exposées à des conditions environnementales agressives, incluant l’exposition à l’eau de mer et aux embruns salins. La zone d’action des vagues sur une construction en mer est la section de la plate-forme qui est la plus exposée à l’environnement marin agressif et à l’eau de mer. La conception des structures en mer est régie par des codes de conception obligatoires afin d’assurer la sécurité et l’intégrité des structures. La plupart des équations disponibles pour l’espacement des fissures ont été développées pour des structures de bâtiments utilisant des résistances normales du béton et un enrobage normal de béton. Toutefois, les structures en mer sont construites en utilisant du béton à haute résistance et un enrobage épais de béton. Très peu d’information est publiée sur l’analyse des fissures dans du béton à haute résistance et un enrobage épais de béton pour les utilisations en mer. Un programme d’essai expérimental a été conçu pour examiner les effets de l’enrobage de béton et de l’espacement des barres d’armature dans du béton normal et à haute résistance sur l’espacement des fissures. Les différentes équations contenues dans les codes sont évaluées par rapport aux résultats expérimentaux. [ABSTRACT FROM AUTHOR]