Structural Engineering Commons^™

Str-811: Examination Of Effective Length Factor For Rc Columns In Non-Sway Frames, S. Ali Mirza, Timo K. Tikka

Canadian Society for Civil Engineering

The Canadian Standards Association (CSA) Standard for Design of Concrete Structures (A23.3-04) permits the use of moment magnifier method for computing the design ultimate strength of slender reinforced concrete (RC) columns that are part of non-sway frames. This computed strength is influenced by the column effective length factor K, effective flexural stiffness EI, and equivalent uniform bending moment diagram factor Cm among others. Previous investigations by the authors examined the equations available in literature for computing EI and Cm factor. For this study, nearly 3000 simple non-sway reinforced concrete frames subjected to short-term loads were simulated and used to investigate …

Str-813: Fragility Of Low-Rise Controlled Rocking Steel Braced Frames With Different Base Rocking Joints, Taylor C. Steele, Lydell D. A. Wiebe

Canadian Society for Civil Engineering

Controlled rocking steel braced frames (CRSBFs) are resilient seismic force resisting systems that can self-centre the structure and prevent structural damage during design-level earthquakes. Energy dissipation may be provided to limit peak displacements, while post-tensioning provides self-centering after rocking. Previous studies have shown that designing energy dissipation and the post-tensioning components in CRSBFs using a response modification factor of R = 8 is sufficient to prevent collapse of structures during earthquakes higher than the design level. However, designers have unique control over the hysteretic behaviour of the system, even after the response modification factor is selected. Additionally, recent studies have …

Str-814: Lessons Learned From The Nairn Avenue Overpass Concrete Girder & Pier Repairs, David A. Neilson, Darren Burmey, Scott Loptson

Canadian Society for Civil Engineering

The Nairn Avenue Overpass is a 213 m long, 11-span, 4-lane + sidewalk precast prestressed concrete I-girder bridge over the CP Keewatin Subdivision line in Winnipeg, MB. The superstructure consists of three continuous segments with deck joints at piers #3 and #8. The structure was built in 1967, and underwent major strengthening and rehabilitation of the deck, girders, and bearings in 1985. Piers consist of a cast-in-place pier cap approximately 18 m long supported on two cast-in-place columns approximately 7 to 8 m tall supported on concrete pile caps over timber raft-pile foundations.

Leaking omega-style strip seal deck joints at …

Str-815: Feasibility Of Using Unbonded Reinforcement In Concrete Block Walls, Henry Miranda, Lisa R. Feldman, Bruce F. Sparling

Canadian Society for Civil Engineering

An experimental program is underway at the University of Saskatchewan to investigate the performance of concrete masonry block walls reinforced with non-prestressed, unbonded reinforcement that are subjected to out-of-plane lateral loads. By eliminating the need for grouting, this construction method may lead to substantially lower wall weights, as well reduced construction times, cost, and workplace injuries. At the same time, the presence of reinforcement will increase the flexural strength of the walls, significantly increasing the allowable vertical spans of such walls as compared to those of comparable unreinforced walls. Unreinforced walls, as well as conventionally reinforced and partially grouted walls, …

Str-816: The Rio Abajo Footbridge: Promoting Development Through The Use Of Resilient Infrastructure, Hendrik Westerink, Alan Kreisa

Canadian Society for Civil Engineering

In the remote farmlands of the developing world, walking is the primary form of transportation. When rivers flood during the rainy season, walks to school, work or the doctor can become life threatening without a bridge to cross. For hundreds of millions of people worldwide, rural isolation caused by a shortage of safe river crossings is a significant impediment to economic development and self-sufficiency. Non-profit organization Bridges to Prosperity (B2P) works with vulnerable communities to build footbridges that create year-round access to essential services. Data describing flood and wind events is often not available in the rural areas of the …

Str-817: The Deck Replacement Of The Honore-Mercier Bridge. An Innovative Solution Using Accelerated Bridge Construction Techniques, Adel R. Zaki, Steve Tselios

Canadian Society for Civil Engineering

Today, the Honoré-Mercier Bridge crosses the St. Lawrence River and the seaway on the west side of the Island of Montreal. Named after the Honorable Honoré-Mercier, a former Premier of Quebec, this bridge became the fourth structure to connect the Island of Montreal to the South Shore. The entire steel structure was built by the Dominion Bridge Company Limited as part of work funded by the government to address the economic downturn. The Honoré-Mercier Bridge was inaugurated 10 months earlier than planned on June 22, 1934, and initially belonged to the Corporation du pont du Lac Saint-Louis. It's administration was …

Str-818: The Effect Of Relaxation On The Slip Resistance Of Metallized Faying Surfaces In Slip-Critical Connections, Maxime Ampleman, Charles-Darwin Annan, Mario Fafard, Éric Lévesque

Canadian Society for Civil Engineering

Metallizing has emerged as an effective protective coating for steel bridge members, providing a physical barrier and a galvanic protection. Recent research has shown that metallized faying surfaces used in high strength bolted connections provide higher slip resistance than specified values for uncoated blast-cleaned faying surfaces in North American design standards. As a particularity, relaxation of the clamping force is observed in the slip-critical connections with metallized faying surfaces. In this study, tests were designed to evaluate the effect of relaxation on the slip resistance of metallized faying surfaces in high strength bolted connections. Some design parameters included in this …

Str-823: Flexural Behaviour And Bond-Dependent Coefficient Of Basalt Frp Bars In Concrete Beams, Fareed Elgabbas, Ehab Ahmed, Brahim Benmokrane

Canadian Society for Civil Engineering

This paper presents an experimental study aimed at determining the bond-dependent coefficient (kb) and investigating the flexural performance of concrete beams reinforced with ribbed basalt fiber-reinforced polymer (BFRP) bars. The performance of the BFRP-RC concrete beams is compared against that of GFRP-RC ones. A total of five concrete beams measured 200 mm wide × 300 mm deep × 3100 mm long were constructed and tested in four-point bending over a clear span of 2700 mm. The main variables were reinforcement type (BFRP, GFRP, and steel bars as reference) and reinforcement ratio. The test results showed that the average kb was …

Str-824: Fatigue Behavior Of Concrete Underground Chambers Reinforced With Gfrp Bars, Michaël Guérin, Hamdy M. Mohamed, Brahim Benmokrane

Canadian Society for Civil Engineering

Precast underground concrete chambers reinforced with steel bars are used frequently in construction and electrical industry for housing power cables and transformers. In Quebec, more than 30,000 of these chambers have been installed by Hydro-Quebec during the last 30 years. However, like other conventionally reinforced concrete structures, corrosion of steel reinforcement constitutes the major cause of chambers deterioration, leading to costly repairs and rehabilitation as well as a significant reduction in service life. This paper presents experimental data on the fatigue and static behavior of full-scale underground concrete chamber reinforced totally with glass fiber-reinforced polymer (GFRP) bars. The chamber measure …

Str-827: Shear Strength Of Circular Concrete Beams Reinforced With Gfrp Bars, Ahmed H. Ali, Hamdy M. Mohamed, Brahim Benmokrane

Canadian Society for Civil Engineering

This paper presents the results of an investigation of the shear strength and behavior of three circular concrete beams reinforced with glass-FRP (GFRP) bars and spirals. The beams, which measured 3,000 mm in length by 500 mm in diameter, were tested under four-point bending. The test parameters included the GFRP-spiral-reinforcement ratio (different spiral spacings [150 and 200 mm] and spiral diameters [13 and 15 mm]). As designed, the beams failed in shear due to GFRP-spiral rupture. The test results indicated that the higher the GFRP spiral reinforcement ratio, the higher the enhancement of the shear strength due to the confinement, …

Str-828: Behavior Of Circular Frp-Reinforced Concrete Columns Under Eccentric Loading, Abdeldayem Hadhood, Hamdy M. Mohamed, Brahim Benmokrane

Canadian Society for Civil Engineering

This paper presents the results of an investigation of the eccentric compression behavior of three full-scale circular concrete columns reinforced with the glass-fiber-reinforced polymer (GFRP) bars and spirals. The column specimens measured 1500 mm height, 305 mm diameter and were tested under monotonic eccentric loading. The main variable was the eccentricity-to-dimeter ratio. Three values were considered in this study (8.20%, 16.39%, and 65.57%). The failure mechanism was changeable according to the level of the applied eccentricity. The failure mechanism of columns at small eccentric loading was defined as compression-controlled due to concrete crushing. At high eccentric loading, the failure of …

Str-829: Behavior Of Gfrp-Reinforced Concrete Squat Walls Under Simulated Earthquake Loading, Ahmed Arafa, Ahmed Sabry Farghaly, Brahim Benmokrane

Canadian Society for Civil Engineering

Steel-reinforced squat walls are used as the main component for earthquake resistance in low-rise structures. Deterioration due to corrosion of steel reinforcement is one of the major challenges facing the construction industry. Furthermore, given the low aspect ratio of squat walls, their behavior is dominated by inelastic shear deformations activated by the yielding of flexural reinforcement. These deformations degrade strength and stiffness with subsequent shear failure, preventing the wall from achieving its flexural capacity, which is a prerequisite for adequate seismic design. Using noncorrodible glass-fiber-reinforced-polymer (GFRP) bars represents an effective method for overcoming corrosion problems. In addition, the available experimental …

Str-830: Enhancing The Deformation Capacity Of Concrete Shear Walls Reinforced With Gfrp Bars, Ahmed Hassanein, Nayera Mohamed, Ahmed Sabry Farghaly, Brahim Benmokrane

Canadian Society for Civil Engineering

An experimental study was recently conducted to address the applicability of concrete shear walls entirely reinforced with glass-fiber-reinforced polymer (GFRP) bars and subjected to quasi-static reversed cyclic lateral loading in attaining reasonable strength and drift requirements specified in different codes. The reported test results clearly show that properly designed and detailed GFRP-reinforced concrete (RC) walls could reach their flexural capacities with no strength degradation. The results also demonstrate that the tested walls were able to achieve recoverable and self-centering behavior up to allowable drift limits before experiencing moderate damage and attain a maximum drift comparable to steel-RC walls. The promising …

Str-831: Fatigue Strength Of Angle-Shaped Transverse Connection For Gfrp-Reinforced Precast Full-Depth Deck Panels In Accelerated Bridge Construction, Mahmoud Sayed-Ahmed, Khaled Sennah

Canadian Society for Civil Engineering

Prefabricated bridges elements and systems (PBES) are subjected to repeated truck loads while being exposed to weather conditions. Fatigue of the structural elements and corrosion of the reinforcement are the main reasons for bridge deterioration. This research investigates the fatigue strength of full-depth deck panels (FDDP) resting over steel cross-braced girders and reinforced with ribbed-surface, high-modulus (HM), glass fiber reinforced polymer (GFRP) bars. The precast FDDP has transverse panel-to-panel connection of angle-shape with female shear key, and panel-to-girder connection of V-shape, where both connections are filled with ultra-high performance fiber reinforced concrete (UHPFRC). Two different fatigue loading were conducted to …

Str-832: Ultimate Flexural Strength And Long-Term Creep Deflection For Structural Insulated Foam-Timber Sandwich Panels, Mahmoud Sayed-Ahmed, Khaled Sennah, Ahmed Diab, Sherif Mansour

Canadian Society for Civil Engineering

The structural insulated panel (SIP) is a sandwich structured composite that is prefabricated by attaching a lightweight thick core made of Expanded Polystyrene (EPS) foam laminated between two thin, and stiff face skins made of Oriented Strand Board (OSB). The use of sandwich panels provides key benefits over conventional materials including: very low weight; high stiffness; durability and; production and construction cost savings. The facing skins of the sandwich panel can be considered as the flanges for the I-beam carrying bending stresses in which one face skin is subjected to tension, and the other is in compression. The core resists …

Str-833: Evaluation Of The Contribution Of Panel Zones To The Global Performance Of Moment Resisting Frames Under Seismic Load, Paul Steneker, Lydell D. A. Wiebe

Canadian Society for Civil Engineering

Before the 1994 Northridge Earthquake, the seismic design strategy for moment resisting frames considered the yielding of the panel zone when calculating the required level of ductility. Following the unacceptable performance of conventional moment resisting frame (MRF) connection details during the Northridge seismic event, prequalified connections were developed to concentrate beam yielding away from the column face, preserving the connection. With these new connection strategies, the panel zone deformation may not contribute as significantly to the overall behaviour of an MRF. Therefore, considering the increased use of advanced dynamic modeling techniques, it is important for both designers and researchers to …

Str-834: Seismic Performance Of Modular Steel Frames Equipped With Shape Memory Alloy Braces, Papia Sultana, Maged A. Youssef

Canadian Society for Civil Engineering

Modular steel buildings (MSBs) are widely used for one to six storey schools, apartments, and similar buildings, where repetitive units are required. Modular units are first built and finished under a controlled manufacturing environment. They are then transported to the building site, where they are connected horizontally and vertically. The lateral load resisting system for MSBs usually relies on steel braced frames, which dissipate the seismic energy through steel yielding. This behaviour leads to residual drifts complicating the repair of seismically damaged buildings or rendering them as irreparable. Systems that can minimize the seismic residual drifts are thus needed. Superelastic …

Str-836: State-Of-The-Art In Near-Field And Contact Explosion Effects On Reinforced Concrete Columns, Alok Dua, Abass Braimah

Canadian Society for Civil Engineering

Blast loads are categorized as far-field and near-field loads in terms of the scaled distance. Far-field and near-field loading are associated with explosions that occur at scaled distances of more than or less than 1.18 m/kg1/3, respectively. The blast waves from a far-field explosion arrive simultaneously at and exert uniformly distributed pressure on a target. Response computations can be performed using the semi-empirical relations (charts) presented in UFC-3-340 design manual, ConWep program or high fidelity physics based commercial software like LS-DYNA, AUTODYN, and ABAQUS. On the other hand, for near-field blasts, the interaction between blast waves and structures is more …

Str-837: Punching Shear Behaviour Of High Strength Concrete Slab-Column Connections Reinforced With Gfrp Bars, Ahmed M. Hussein, Ehab El-Salakawy

Canadian Society for Civil Engineering

The catastrophic nature of punching shear failure exhibited by flat plate system requires a great attention and robust predictions of the behaviour of slab-column connections. This paper presents an experimental study carried out to investigate the punching shear behaviour of fibre-reinforced polymer (FRP) reinforced concrete (RC) interior slab-column connections made of high strength concrete (HSC). Three full-scale HSC specimens were constructed and tested up to failure. The three connections were reinforced with GFRP sand-coated bars with reinforcement ratios of 1.0, 1.5 and 2.0% without any shear reinforcement. The typical dimensions of the test specimens were 2800 × 2800 × 200 …

Str-839: Addressing The Issues Of Modal Identification Using Tensor Decomposition, Peter W. Friesen, Ayan Sadhu

Canadian Society for Civil Engineering

Modal identification has been an indispensable tool for condition assessment of critical civil infrastructure. Recently several signal processing techniques including time-frequency analysis have shown significant success in addressing wide range of challenges in modal identification of flexible structures. In a parallel development, tensor decomposition is explored as an attractive and versatile system identification tool that can use even a limited number of vibration sensors to estimate the modal parameters under ambient excitations. In this paper, the performance of tensor decomposition is evaluated for modal identification of a building model under a multitude of earthquake excitations.