Structural Engineering Commons^™

Mat-713: Evaluation Of Ndt Techniques For Concrete Bridge Decks Using Fuzzy Analytical Hierarchy Process, Tarek Omar, Moncef L. Nehdi

Canadian Society for Civil Engineering

Considering the colossal backlog of deteriorating bridges, transportation agencies need to systematically evaluate bridge deck conditions in order to optimize the timing, scope, and approach of preventive maintenance, repair, and replacement. Over the last few years, there have been growing interest among bridge infrastructure stakeholders in using non-destructive methodologies for bridge inspection, evaluation, and maintenance. Nondestructive testing (NDT) techniques can provide needed information about the “under-the-surface” deteriorated condition of bridge decks. This paper examines the most common NDT technologies for assessing bridge decks. Each technology was rated based on five performance measures: capability to detect subsurface defects, speed of data …

Mat-714: Condition Assessment And Deterioration Prediction Tools For Concrete Bridges: A New Look, Tarek Omar, Moncef L. Nehdi

Canadian Society for Civil Engineering

Structural problems created by corrosion, ageing, aggressive environments, material defects and unforeseen mechanical or seismic loads can compromise the serviceability and safety of bridges. The importance of an effective bridge-management system (BMS) cannot be overstated, especially in light of the recent collapse of bridges in North America and elsewhere. Several technologies are available for assessing the condition of concrete bridges and a number of deterioration models are used to predict future bridge conditions and estimate associated funding requirements. This paper critically reviews the different available condition assessment and deterioration prediction approaches for concrete bridges. The potential applications of condition assessment …

Mat-719: Investigation Of Grouted Precast Concrete Wall Connections At Subfreezing Conditions, Douglas James Provost-Smith, Mohamed Elsayed, Moncef L. Nehdi

Canadian Society for Civil Engineering

The effect of exposing grouted precast wall connections to subfreezing curing temperatures at early-age was explored in this study. In cold weather construction, heating of the surrounding environment of grouted precast wall connections is usually conducted for short periods of time. Hence, subfreezing conditions can affect the strength of the grout and the bond strength of the connection, which can ultimately compromise the integrity of the structure. In this study, grout specimens typical of that used in precast wall construction were cured at ambient conditions for one day, and then placed in an environmental chamber at subfreezing temperatures (-10°C and …

Mat-720: Effect Of Pore Structure On Concrete Deterioration By Physical Sulphate Attack, Ahmed R. Suleiman, Moncef L. Nehdi

Canadian Society for Civil Engineering

Repeated crystallisation of salt minerals has been considered as the driving force for surface scaling of concrete exposed to physical sulphate attack. This damage is initiated when stresses induced by the internal pressure created via repeated salt crystallisation exceed the tensile strength of the concrete. The degree of such damage will depend mainly on the structure and connectivity of pores, which control the penetration of sulphates into the concrete. Several factors affect the pore structure including the concrete constituents, mixture proportions and the curing process. Therefore, in this paper, the effect of the pore structure on concrete deterioration by physical …

Mat-722: Effect Of Fiber Orientation On The Behavior Of Cfrp Confined Concrete Cylinders, Ahmed Sulaiman, Husham Almansour, Hassan Aoude

Canadian Society for Civil Engineering

This paper presents the results of an ongoing experimental investigation examining the effect of fiber orientation and stacking sequence on the behavior of FRP-confined concrete. As part of the experimental study, 100 mm x 200 mm concrete cylinders were jacketed with carbon fiber reinforced polymer (CFRP) sheets and tested under pure axial compressive loading. The specimens were confined using various CFRP stacking sequences, with fibers oriented at 0⁰, 90⁰, and ±45⁰. Furthermore, within each stacking sequence, the numbers of layers was varied from 4 to 8 to examine the effect of number of plies on the behavior of the FRP-confined …

Mat-723: Bond Behaviour Of Grouted Connections Under Monotonic Tensile Loads, Mohamed Elsayed, Douglas James Provost-Smith, Moncef L. Nehdi, Osama Eissa

Canadian Society for Civil Engineering

Grouted bar-in-conduit connections are versatile connections widely used in the precast concrete construction. In precast load bearing wall structures, two vertical wall panels are connected by a reinforcing bar, which is projected from one panel and grouted into a sleeve placed in the other. The main function of the ties is to resist tension induced by in-plane and out-of-plane straining actions and to provide ductility to the wall assembly through the yielding of the reinforcement. Limited information is currently available on the behaviour of such connections. This paper presents the findings of an investigation conducted to investigate the behaviour of …

Mat-732: Experimental Study On The Capacity Of Barrier Deck Anchorage In Mtq Pl-3 Barrier Reinforced With Hm-Gfrp Bars With Headed Ends, Michael Rostami, Khaled Sennah, S. Milad Dehnadi

Canadian Society for Civil Engineering

A recent design work conducted at Ryerson University on PL-3 bridge barrier has led to an economical glass fibre reinforced polymer (GFRP) bar detailing for sustainable construction. A PL-3 barrier wall of 27.6 m length was constructed using the proposed GFRP bar configuration, incorporating the use of V-Rod headed-end bars. The proposed barrier configuration was recently crash tested to qualify its use in Canada’s highway bridges. Then, wall segments of this barrier were tested under static loading to-collapse to determine their structural behavior, crack pattern and ultimate load carrying capacity under simulated vehicle impact load. Test results led to establishing …

Mat-734: Increasing The Durability And Resilience Of Tall Buildings With Precast Concrete Enclosure Systems, Randy A. Van Straaten, John F. Straube, C. Alex Lukachko

Canadian Society for Civil Engineering

In this paper precast concrete wall systems are compared to curtain wall and window wall systems in terms of durability and disaster resilience of multi-story buildings. Window wall systems are currently the enclosure system of choice for tall residential buildings in most parts of North America.

Precast concrete wall systems can be expected to last the lifetime of a building with routine seal replacement. These are highly durable systems. Windows within precast concrete wall systems will require replacement in 25-35 years but represent a limited portion of the wall area and hence are less costly and have less impact on …

Mat-735: Optimizing Performance Of Zinc Coated Reinforcing Steel In Concrete Structures, Martin Gagné, Shannon Pole, Frank Goodwin, Gary Dallin

Canadian Society for Civil Engineering

Corrosion of steel reinforcing bar (rebar) is the most significant cause of concrete failure, resulting in expensive repairs and premature structure replacements across the country. This paper will discuss a new, low-cost, zinc coating process for rebar. The properties of this new coated rebar and its contribution to improvement of concrete performance will be presented together with the status of related national and international standards. The Continuous Galvanized Rebar (CGR) coating process is similar to galvanizing of sheet steel. The zinc coating is durable and resistant to abrasion that is routine during transport and construction, but is also highly ductile …

Mat-744: Assessment Of Performance Of Bio Self-Healing Mortar Using Diatomaceous Earth And Silica Fume, Ahmed J. Al Bughdadi, Mohamed N. Abou-Zeid

Canadian Society for Civil Engineering

Cracking represents a major threat for the integrity and performance of structures. Self-healing concept was introduced to construction materials in order to enhance their performance and extend their service life with less repair. This study aims at assessing the performance of Portland cement mortar incorporating self-healing Bacillus Pseudofirmus bacteria using Diatomaceous earth (DE) to immobilize precursor and bacteria in mortar and lowering the pH level of mortar by using silica fume to provide a suitable growth environment for bacteria to generate limestone. The specimens were prepared at three different bacteria dosages and three DE dosages. Cracking of specimens was induced …

Mat-745: The Effect Of Ground Granulated Blast Furnace Slag And Silica Fume On The Durability Of High Performance Concrete In Bridge Decks, Abdulaziz Alaskar, R. Douglas Hooton

Canadian Society for Civil Engineering

High-performance concrete typically has a low water to cementing materials ratio (w/cm), high binder content and may contain high levels of supplementary cementitious materials. The effects of ground granulated blast furnace slag (GGBFS) and silica fume (SF) on the durability of HPC were investigated. In this study, HPC mixtures at 0.33 w/cm were made with two sources of blended cements containing 8% SF mixed with 25 and 50% GGBFS replacements by mass of cement. The compressive strength, drying shrinkage, thermal deformation and transport properties were tested. The preliminary test results have shown that increased fineness of the blended cement enhances …

Mat-755: Sustainable Road Construction For Heavy Traffic Using High Strength Polymeric Geocells, Sanat K. Pokharel, Meisam Norouzi, Ian Martin, Marc Breault

Canadian Society for Civil Engineering

Construction Sustainability has been the focus of debate ever since the Brundtland commission report ‘Our Common Future’ defined Sustainable Development. Kyoto Protocol and subsequent climate change conferences leading up to the Paris submit this year has put still more emphasis on this agenda. Construction of heavy traffic unpaved access roads require huge amount of aggregate mining and long haulage in the areas of scarce virgin aggregate. Conventional practices in these road constructions seek structural adequacy but never specifically address the sustainability issue. Innovative technology that can reduce the volume of aggregate material while maintaining the structural integrity is required to …

Str-805: Experimental Evaluation Of The Robustness Of Wt Connections Under Quasi-Dynamic Load, Megan E. Hayes, Christopher H. Raebel, Christopher M. Foley

Canadian Society for Civil Engineering

Flexible (simple) shear connections commonly used in steel-framed buildings are very economical and are relatively easy to fabricate. These connections are used for shear resistance, but recent studies have shown that they are capable of sustaining an interaction of rotational and axial load demand necessary for steel-framed building structures to help resist collapse in the event of unanticipated damage scenarios.

The objective of this paper is to outline and discuss an experimental effort designed to evaluate the robustness of flexible WT connections. The experimental program included twelve full-scale tests of a system consisting of two wide flange beams connected to …

Str-806: Experimental Evaluation Of The Robustness Of Single Plate Shear Connections Under Quasi-Dynamic Load, Jacklyn E. Lesser, Christopher H. Raebel, Christopher M. Foley

Canadian Society for Civil Engineering

Flexible (simple) shear connections commonly used in steel-framed buildings are very economical and are relatively easy to fabricate. These connections are used for shear resistance, but recent studies have shown that they are capable of sustaining an interaction of rotational and axial load demand necessary for steel-framed building structures to help resist collapse in the event of unanticipated damage scenarios.

The objective of this paper is to outline and discuss an experimental effort designed to evaluate the robustness of single plate shear connections under a quasi-dynamic loading scenario simulating the loss of a central column. The experimental program included eleven …

Str-807: Ansys Modeling Of Post-Tensioned Steel Beam-Column Connections Under Cyclic Loading, Saber Moradi, M. Shahria Alam

Canadian Society for Civil Engineering

Permanent deformations in a steel moment resisting frame can be eliminated by using post-tensioned (PT) elements. This paper presents the development of three-dimensional finite element models of PT steel beam-column connection subassemblies. Knowing that there is limited experimental data in the literature on PT steel connections with top-and-seat angles, reliable finite element models can be used to investigate the load carrying behaviour of PT steel connections as well as producing more data for these new connections. In this paper, finite element modelling, meshing, and analysis are performed in the commercial software, ANSYS. The analysis includes geometric and material nonlinearities, pre-loaded …

Str-808: Re-Testing Of A Fire-Damaged Bridge, Alexander M. C. Au

Canadian Society for Civil Engineering

A proof load test was performed on a fire-damaged bridge in October 2008 and its load capacity was confirmed. The bridge was then re-opened for full traffic shortly after the load test. It was further repaired in 2009 which included concrete patching and carbon fibre reinforced polymer (CFRP) warping of 6 girders in the main span. The bridge is located at one of the busiest highways of the country with many heavy trucks passing daily. Also, reinforced concrete could deteriorate much faster than usual after the fire accident. In 2014, the Bridge Office was requested to re-test the bridge in …

Str-810: A Formulated Approach To Cisc Shear Connection Resistance And Flexibility Design, Josiah J. Matthews, Kaveh Arjomandi

Canadian Society for Civil Engineering

The design of simple shear connections has been extensively studied by several researchers. The design requirements for ductility and strength of these connections have been established through both experimental and theoretical approaches. However, the current Canadian design guidelines such as the Handbook of Steel Construction published by the Canadian Institute of Steel Construction (CISC) do not provide a formulated approach for the design of shear connections. In addition, the CISC design approach is somewhat out dated when it comes to providing adequate rotational ductility. In this paper, a formulated approach for the design of bolted double angle shear connections considering …

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 …