Engineering Commons^™

Investigation Of Grouted Dowel Connection For Precast Concrete Wall Construction, Douglas J. Provost-Smith

Electronic Thesis and Dissertation Repository

The grouted dowel connection is a simple and cost-effective connection used in many precast concrete structural systems. The required dowel length is currently designed as a regular bar in reinforced concrete, which underestimates the bond strength, thus resulting in excessive connection lengths. Furthermore, precast wall construction continues throughout cold weather, where in-situ heating of the grout used in the grouted dowel connections is usually conducted for short periods of time. Hence, early-age exposure to subfreezing conditions may affect the quality of the grout and subsequently the bond strength of the connection, which can compromise structural integrity.

In this thesis, full-scale …

Development Of Design Loads For Transmission Line Structures Subjected To Downbursts Using Aero-Elastic Testing And Numerical Modeling, Amal Elawady

Electronic Thesis and Dissertation Repository

The failure of transmission line structures due to severe High Intensity Wind (HIW) events is one of the major problems facing the electrical utility companies in various places around the globe including Canada. An extensive research program focusing on this problem started about fifteen years ago at The University of Western Ontario (UWO). In this Thesis, two major milestones are achieved leading to the advancement of the knowledge in this field. The first milestone is conducting, for the first time, a test on an aero-elastic model of a multi-span transmission system under reduced–scale simulated downbursts. The first objective of the …

Behavior Of Fire-Exposed Rc Frames Before And After Jacketing, M. Monir M. Ajan Alhadid

Electronic Thesis and Dissertation Repository

Analysis and design of fire-exposed Reinforced Concrete (RC) frames before and after jacketing with concrete layers are commonly performed using prescriptive methods that rely on the concept of fire rating. These methods were developed based on empirical results on individual RC members subjected to certain fire conditions. In typical fire scenarios, the residual capacity, stiffness and thermal deformations affects not only the local performance of each fire-exposed member, but also the load redistribution and global behavior of the entire frame. In terms of fire safety, the philosophy of the new building codes considers objective-based design as an alternative of the …

Enhancing The Seismic Performance Of Steel Structures Utilizing Superelastic Shape Memory Alloys, Papia Sultana

Electronic Thesis and Dissertation Repository

Although conventional earthquake-resisting structural systems provide the life safety level during earthquakes, they experience significant structural damage when exposed to strong ground shaking that render structural retrofitting as uneconomical. Superelastic shape memory alloys (SMAs) can be used in steel structures to reduce the residual deformations due to their recentering capability, which can facilitate post-seismic retrofitting. The primary aim of this thesis is to enhance the seismic performance of both regular and modular steel structures using an optimum amount of superelastic SMAs material in terms of maximum inter-storey drift, residual drift, and damage scheme.

First, a simplified method based on pushover …

Numerical Studies For Improving Fracture Toughness Resistance Curve Testing Using Single-Edge (Notched) Tension Specimens, Yifan Huang

Electronic Thesis and Dissertation Repository

The fracture toughness resistance curve, i.e. the J-integral resistance curve (J-R curve) or the crack tip opening displacement resistance (CTOD-R) curves, is widely used in the integrity assessment and strain-based design of energy pipelines with respect to planar defects (i.e. cracks). This thesis deals with issues related to the experimental determination of the J(CTOD)-R curves using the newly-developed single-edge (notched) tension (SE(T)) specimens. In the first study, the plastic geometry factor, i.e. the η_pl factor, used to evaluate J in a J-R curve test based on …

Innovating Two-Stage Concrete With Improved Rheological, Mechanical And Durability Properties, Manal F. Najjar

Electronic Thesis and Dissertation Repository

Two-stage concrete (TSC), also known as preplaced aggregate concrete, is a special type of concrete that is produced using a unique procedure which differs from that of conventional concrete. TSC is distinguished by its high coarse aggregate content and exceptional placement technique, whereby aggregates are first pre-placed in the mold then injected with a special grout. The preplacement of aggregates saves substantial energy since only the grout needs mechanical mixing; the grout is self-leveling and needs no vibration and no mechanical compaction. However, TSC applications are still limited despite substantial advancement of modern concrete technology. Therefore, there is a need …

Mat-705: Improving The Efficiency Of Zinc Sacrificial Anodes In Repaired Concrete, Ahmed G. Bediwy, Mohamed T. Bassuoni, Martin Beaudette

Canadian Society for Civil Engineering

Zinc sacrificial anodes are considered an effective and economical method to prevent the electrochemical corrosion of steel bars by providing cathodic current to bars, which can provide corrosion protection at low galvanic current densities in the range of 0.2 to 2 mA/m2. Sacrificial anodes are commonly used in RC structures particularly in bridge decks to mitigate a critical phenomenon that occurs in the original concrete beside the repaired patches, which is known as the ‘halo effect’. One of the key factors affecting the efficacy of zinc anodes is the resistivity of concrete or cementitious repair material in which these anodes …

Mat-701: Predicting The Compressive Strength Of Ultra-Lightweight Concrete By An Artificial Neural Network, Jordan Ouellet, Jean-Luc Martel, Claudiane Ouellet-Plamondon, Alan Carter

Canadian Society for Civil Engineering

Ultra-lightweight concrete (ULWC) has potential applications for floating structures and architectural elements because of its dry density coming in at under 1000 kg/m3. The objective was to develop an artificial neural network (ANN) to aid the ULWC designer according to his needs. Boundary conditions were set for each material and 13 constraints based on the water binder ratio, density, air content, binder and aggregate content. The ANN predicted the compressive strength with a comfortable margin of error, with the gap encountered being attributed to variability in workability. Precise constraints and boundary conditions are needed to ensure a lower variability in …

Mat-704: Resistance Of Concrete Incorporating Portland Limestone Cement To Sulfuric Acid, Mahmud Amin, Mohamed T. Bassuoni

Canadian Society for Civil Engineering

Concrete has long been the most popular choice for constructing key infrastructural elements such as sewer pipes, water treatment facilities, industrial floors and foundations. However, many field cases from all around the world have shown that concrete elements in these environments are severely damaged due to biogenic and/or chemical sulfuric acid attack. Since high alkalinity is required for the stability of the cementitious matrix, concrete is highly prone to acid attacks, which decalcify and disintegrate the hydrated cement paste to various levels based on exposure conditions and type of concrete. Numerous studies have been conducted to enhance the durability of …

Mat-707: Development Of Enhanced Test Methods To Evaluate Alkali-Silica Reaction In Concrete, Noura Sinno, Medhat Shehata

Canadian Society for Civil Engineering

The research presented in this paper studies the effect of sample geometry and temperature on expansion due to alkali-silica reaction (ASR) in concrete. Expansions of cubes and cylinders are compared to those of the standard prisms. Control samples, samples with fly ash (FA) and others with slag are investigated at two temperatures, 38°C and 60°C. At 38°C, results showed that smaller samples have higher expansion at early ages. However, larger samples such as cubes and cylinders seem to reach higher expansion compared to prisms after 32 weeks for both control and samples with fly ash. In addition, the results showed …

Mat-708: Monitoring The Corrosion Process Of Reinforced Concrete Flat Slab-Column Connection, Mahmoud E. Said, Amgad Hussein, Assem A. A. Hassan

Canadian Society for Civil Engineering

The corrosion of the steel reinforcement embedded in a two-way reinforced concrete flat slab around the column stub area was investigated in this study, which aimed to studying the effect of corrosion on the shear punching behavior. Two square flat slab-column connections were cast, the flat slab dimension was 1900 mm × 1900 mm × 150 mm, and the column dimensions was 250 mm × 250 mm. A specific delaminated area was corroded around the column stub to emphasize the effect of corrosion around punching area. The corrosion reached two levels of mass loss uniformly over that specified area: 0% …

Mat-711: Utilization Of Recycled Crumb Rubber In Structural Self-Consolidating Concrete, Mohamed K. Ismail, Assem A. A. Hassan, Madolyn A. Lundrigan

Canadian Society for Civil Engineering

The present work evaluates the impact of using recycled crumb rubber (CR) as a partial replacement of fine aggregate on the fresh and mechanical properties of concrete composite, especially when self-consolidating concrete is used. In this study, seven mixtures containing various amounts of fine CR (0-30% by volume of sand) were tested. The fresh properties tests included flowability, passing ability, and segregation resistance. On the other hand, the mechanical properties tests included compressive strength, modulus of elasticity, splitting tensile strength, and flexural strength. The results indicated that although increasing the CR replacement decreased the fresh and mechanical properties of concrete, …

Mat-702: Mechanical Behaviour Of Ultra-High Performance Concrete Obtained With Different Concrete Constituents And Mix Designs, Mahmoud Sayed-Ahmed, Khaled Sennah, Moulay Youssef Monsif

Canadian Society for Civil Engineering

This research investigates the mechanical behaviour for the Ultra-High Performance Concrete (UHPC) and UltraHigh Performance Fiber Reinforced Concrete (UHPFRC). UHPC and UHPFRC are designed to be self-consolidated concrete that level itself without mechanical vibration due to its highly flowability and moderate viscosity. UHPFRC is used as joint-fill cementitious materials for the connections of prefabricated bride elements and systems used for the Accelerated Bridge Construction and rapid bridge replacement. The main concrete constituents of such materials consist from: binders (cement), powders (fillers), liquids (additives), water, and fibers. Hence, the mixture proportion design should follow a densified mixture design algorithm to densify …

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-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-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-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-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-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-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 …

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-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 …

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-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-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 …