Engineering Commons^™

Numerical Modelling Of Externally-Bonded Fiber Reinforced Polymer Shear-Strengthened Reinforced Concrete Beams Subjected To Fatigue Loading, Nagwa Ibrahim Fares

Theses

An extensive number of existing structures persistently exposed to fatigue loading such as bridges, offshore structures, pavements, and highways, are in urgent need of repairing and strengthening. This may be attributed to the continuous increase in the load requirements, change of the structure’s function, and meeting current load standards. Among the potential methods of rehabilitation and strengthening of existing reinforced concrete structures, the externally bonding fiber reinforced polymers (FRP) composites are gaining massive popularity and becoming a viable and cost-effective method. Shear failure of reinforced concrete (RC) beams is known to be brittle, which occurs without prior sufficient warnings; therefore, …

Using Metal-Organic Frameworks (Mof) To Reduce The Carbon Footprint Of Concrete, Mona Ibrahim El-Hallak

Theses

The production of concrete by the construction industry has a massive impact on the environment. The process of manufacturing its main component, cement, releases a considerable amount of anthropogenic carbon dioxide. This thesis is concerned with the production of sustainable and eco-friendly concrete that integrates metal-organic frameworks (MOF) to capture and offset the CO₂ emissions emitted during the production of cement. The main objective is to synthesize a MOF capable of capturing CO₂ in concrete through accelerated carbonation curing and to assess its impact on concrete performance. Different parameters were examined, including the MOF content, initial curing duration, …

Behavior Of Steel Fiber Reinforced Concrete Made With Recycled Concrete Aggregates: Material Characterization And Deep Beam Shear Response, Nancy Kachouh

Dissertations

This research aims to examine the performance of concrete made with recycled concrete aggregates (RCAs) and steel fibers. It comprises material characterization tests, large-scale reinforced concrete (RC) deep beam tests, and numerical modeling. Material characterization test parameters included the RCA replacement percentage (30, 70, and 100%) and the steel fiber volume fraction (vf = 1, 2, and 3%). Fourteen large-scale deep beam numerical models with and without web openings made with 100% RCAs and steel fibers were developed and validated through a comparative analysis with test results. A numerical parametric study was conducted to investigate the effect of varying …

Strengthening Of Concrete Deep Beams Using Carbon Fabric Reinforced Cementitious/Geopolymeric Matrix, Nour Mohamed Muhsen Khir Allah

Theses

This research aimed to examine the effectiveness of using carbon fabric-reinforced matrix (C-FRM) composites to improve the shear response of reinforced concrete (RC) deep beams. Ten RC deep beams with a/h of 1.6 were tested, where a is the shear span and his is the beam depth. Test parameters included the presence of internal shear reinforcement (no shear reinforcement and minimum shear reinforcement), number of C-FRM composite layers (one and two layers), angle of inclination of the second layer of CFRM (90o and 0o with respect to the longitudinal direction of the beam), and type of matrix (cementitious and geopolymer). …

Environmental Assessment Of The Impact Of Land-Based Discharges On Marine Water And Sediment Quality In Dubai, Uae, Ayman Fathy Halawa

Theses

The current seawater and Creek – Canal waterway in the Emirate of Dubai, UAE, is under tremendous pressure because of continuous urban water discharges from land-based sources. Therefore, the impact of urban water discharges on marine water and sediment quality in the Emirate requires a thorough assessment. The main objective of this study is to assess the impacts of effluent discharges on the quality of water and sediment in the open sea and Dubai Creek. The land-based sources include the power and desalination plants, industrial sector, sewage treatment plant, and stormwater runoff. To achieve the stated objective, relevant data on …

Performance Evaluation Of Cement-Free Geopolymer Concrete Made With Recycled Concrete Aggregates And Steel Fibers, Jamal Ahmad Samer Medljy

Theses

Sustainable and innovative alternatives have been investigated to replace concrete’s main components, natural aggregates, and cement. Previous studies have been carried out to replace NA and cement with recycled concrete aggregates (RCA) and inorganic alkali-activated geopolymer binders, respectively. Yet, such sustainable concrete has only been proposed for non-structural purposes, owing to the inferior properties of RCA. This research work aims to assess the feasibility of reutilizing RCA from construction and demolition waste and locally available industrial solid by-products in the production of sustainable geopolymer concrete for structural applications. The binding materials were either in the form of a single precursor, …

Behavior Of Steel Fiber-Reinforced Geopolymer Concrete Made With Recycled Concrete Aggregates, Abdalla Ahmed Moallim Hussein

Theses

Industrial by-products and recycled concrete aggregates (RCA) have the potential to fully replace cement and natural aggregates, respectively, in the production of concrete rather than being discarded wastefully into landfills or stockpiles. Yet, their combined use in the development of a novel RCA geopolymer concrete has been limited to nonstructural purposes, owing to the inferior mechanical and durability properties of said concrete. To improve the properties of geopolymer concrete made with RCA, steel fibers may be added to the mix. This research aims to study the feasibility of reutilizing locally available industrial solid wastes and RCA in geopolymer concrete for …

Performance Of Cement-Free Geopolymer Concrete Made With Ceramic Waste Powder Using Taguchi Method, Ponalagappan Chokkalingam

Theses

The ceramic industry produces a substantial amount of waste during its production processes. Recycling and reutilizing such ceramic waste is a challenge due to its extended biodegradation period. Consequently, the ceramic industry is dedicated to attaining a sustainable solution to dispose of this waste rather than discarding it wastefully into landfills or stockpiles. In turn, the demand for ordinary Portland cement has been on a steady increase, leading to concerns about the sustainability of the construction industry. As a sustainable alternative to cement, alkali-activated binders have been proposed owing to their ability to reduce carbon emissions, preserve nonrenewable natural resources, …

Bond Behavior Of Fabric Reinforced Geopolymeric Matrix-Concrete Joints, Feras Farid Abu Obaida

Civil and Environmental Theses

This research aimed to examine the potential use of a geopolymeric matrix as a sustainable alternative to commercial mortars in carbon fabric-reinforced matrix composites. Single-lap shear tests were conducted to examine the bond behavior at the fabric-matrix interface. Test parameters included the type of matrix (geopolymeric and cementitious matrices), the type of fabric (unidirectional and bidirectional) and the bonded length (50 to 300 mm). The geopolymeric matrix was a blend of fly ash/ground granulated blast furnace slag activated by an alkaline solution of sodium silicate and sodium hydroxide. The bond behavior of the geopolymeric-matrix specimens was characterized and compared to …

Assessment Of Different Seismic Retrofit Systems Of Rc Buildings For Earthquake Risk Mitigation, Aya Ragab Mohamed Abou Ei-Hamd

Theses

Many existing Reinforced Concrete (RC) structures were designed and constructed at a time when design codes were insufficient according to current standards. This class of structures is at risk of damage when subjected to strong earthquake loading. Therefore, several seismic retrofit techniques have been investigated experimentally to increase the earthquake resistance and damage-control potential of pre-seismic code structures using different methods such as quasi-static and pseudo-dynamic testing. However, a limited number of studies have focused on investigating the overall seismic performance of retrofitted RC structures using shake table testing. The first task of this study assesses analytically and experimentally the …

Strengthening Of Concrete Deep Beams With Extreme Discontinuities Using Near-Surface Mounted Composites, Moustafa Seifeddin Mansour

Civil and Environmental Theses

Installation of a web opening that fully interrupts the natural load path in concrete deep beams produces regions of extreme discontinuities and reduces the shear strength. This research examined the effectiveness of using near-surface-mounted carbon fiber-reinforced polymer (NSM-CFRP) reinforcement to restore the shear strength of deep beams with extreme discontinuities. The strut-and-tie model (STM) procedures were utilized to develop three different strengthening solutions around the discontinuity regions. A total of eight deep beam specimens (150 x 500 x2700 mm) with a shear span-to-depth ratio of a/h = 0.8 were constructed and tested. One beam was solid. Seven beams had a …

Assessment Of Carbon Emissions Of Road Projects And Development Of A Framework For Carbon Footprint Calculation Of Roads In The City Of Abu Dhabi, Mohammed H. H. Alzard

Civil and Environmental Theses

Climate change has become a global issue affecting the environment and human health. Transportation is a major contributor of greenhouse gases (GHG) emissions, with road transport being responsible for more than half of these emissions. The main objective of this thesis was to estimate the carbon footprint associated with road projects in the city of Abu Dhabi following a comprehensive approach that considers all activities within the life cycle of roads. Three cases were considered including, Al Rahba City internal road network, the upgrading of Al Salam Street, and the widening of the Eastern Corniche Road. A carbon footprint estimation …

Performance Prediction Of Concrete Deep Beams Containing Cutouts Internally- Reinforced With Composite Bars, Somoud Jebril Arabasi

Theses

The development of code provisions for the use of strut-and-tie model (STM) in structural design has been hindered by great uncertainties due to the lack of experimental evidences. The problem becomes more complex when the conventional steel reinforcing bars around disturbed regions are replaced by non-metallic composite reinforcement. This research aimed to investigate the structural behavior of concrete deep beams with cutouts internally reinforced with glass fiber-reinforced polymer (GFRP) bars around regions of discontinuities. Different STMs were developed for the design of GFRP-reinforced concrete deep beams. The models were analyzed through the use of ACI 318 (2014) and CSA S806 …

Combining Non-Destructive Tests To Improve The Reliability Of Evaluating Concrete Quality, Afra Al Asri Mohammed Obaid Al Dhaheri

Civil and Environmental Theses

Non-destructive tests (NDT) are commonly used in construction to evaluate concrete quality for both existing structures and during construction. The reliability of these tests have been questioned. This thesis is concerned with evaluating concrete strength and durability using different non-destructive tests (NDT). Also, it focuses on applying different combination of NDT to predict the concrete strength and durability using regression models. The main objective of the study was to investigate how to improve the reliability of nondestructive tests NDT to evaluate the concrete quality by combining more than one NDT test for concrete mixtures commonly used in Al Ain city, …

Calibrating And Evaluating Dynamic Rule-Based Transit-Signal-Priority Control Systems In Urban Traffic Networks, Md Didarul Alam

Civil and Environmental Engineering Dissertations

Setting the traffic controller parameters to perform effectively in real-time is a challenging task, and it entails setting several parameters to best suit some predicted traffic conditions. This study presents the framework and method that entail the application of the Response Surface Methodology (RSM) to calibrate the parameters of any control system incorporating advanced traffic management strategies (e.g., the complex integrated traffic control system developed by Ahmed and Hawas). The integrated system is a rule-based heuristic controller that reacts to specific triggering conditions, such as identification of priority transit vehicle, downstream signal congestion, and incidents by penalizing the predefined objective …

A Hierarchical Modelling Approach For Assessing The Impact Factors Of The Measured Of Mobility And Safety At Intersections, Hiba Eyesha Abou-Kassem

Civil and Environmental Theses

Measuring safety and mobility for various types of intersections is crucial in any transportation study. Many factors contribute to changing the effectiveness of the different types of intersections on mobility and safety. Deciding which type of intersection is most suitable in a particular environ and prevailing traffic conditions depends on the number of crashes, injuries, delay time, etc. This study focuses on two intersection types; signalized intersections and non-signalized intersections (only roundabouts). The aim of this research is to devise a theoretical modeling framework and hence a statistical-based methodology that can be used to assess the safety and mobility measures …

Assessment Of Shear Prediction Models For Seismic Loss Estimation Of Concrete Buildings, Bashir Mohamed Ayman Al Murad

Civil and Environmental Theses

No abstract provided.

Recycling Ceramic Waste Powder And Its Usage As An Alternative Ingredient In Concrete, Dima Mamoun Kanaan

Theses

Green environment is a challenging concern to accomplish in today’s world. This could be accomplished through an effective and beneficial recycling system through reusing solid waste materials. The study and exploration of alternative ingredients for concrete-making industry started more than five decades ago. Concrete that contains solid waste is referred to as “Green” concrete. Ceramic tiles are widely used in most structures; its production creates waste powder. Using ceramic waste powder (CWP) as an ingredient to partially replace cement in concrete will have a positive and progressive environmental impact in addition will help reserve natural resources. In this study, CWP …

Shear Behavior Of Steel-Fiber Reinforced Ultra-High-Strength Self-Compacted Concrete Beams, Omar Jum’Ah Za’Al Al Rawashdeh

Theses

Ultra-high-strength concrete is a new class of concrete that has been the result of the progress in concrete material science and development. This new type of concrete is characterized with very high compressive strength; about 100 MPa. Ultra-high strength concrete shows very brittle failure behavior compared to normal-strength concrete. Steel fibers will significantly reduce the workability of ultra-high strength concrete. The development and use of self-compacting concrete has provided a solution to the workability issue. The combination of technology and knowledge to produce Ultra-High strength fiber reinforced self-compacting concrete was proved to be feasible. Few studies investigated the effect of …

Shear Strengthening Of Reinforced Concrete Beams Using Textile-Reinforced Mortar, Oluwafunmilayo Morenike Awani

Theses

The effectiveness of using carbon textile-reinforced mortar as an innovative technique to improve the shear response of reinforced concrete beams has been investigated. The research comprised double-shear bond testing on bond behavior of textile-reinforced mortar, large-scale beam testing on shear response of reinforced concrete beams strengthened with textile-reinforced mortar, and nonlinear finite element modeling of the tested beam specimens. Test variables of the double-shear bond testing were the matrix type, and width/length of the bonded area, whereas for the large-scale beam testing, the variables included the number of textile-reinforced mortar layers, matrix type, and amount of internal stirrups. Results of …

A Two-Stage Fuzzy Logic Model For Urban Traffic Signal Control And Management., Nada Bakri Alnaser

Theses

Different traffic signal control systems are applied nowadays. They vary in complexity and approach but mostly aimed at improving the intersection level of service and the efficiency of the traffic network. Fuzzy Logic Models (FLM) have been widely regarded as quite appealing for real-time applications, in addition to their explicit considerations for stochasticities or uncertainties of traffic measures. The majority of the FLMs for signal control were developed to handle isolated intersections in specific. Very few of these FLM systems explicitly account for neighbor intersections’ traffic impact on the decisions to be made at the underlying intersections.

The aim of …

Capacity Models For Multilane Roundabouts And Their Evaluation Using Microscopic Simulation Models, Mohamad A. Shrayteh

Theses

Compared to previous versions of the manual, the Highway Capacity Manual 2010 has provided more comprehensive capacity models for single and multilane roundabouts. The Highway Capacity Manual 2010 multilane roundabout capacity models are limited to two-by-two lanes, that is, two entry lanes and two circulating lanes. These capacity models are not valid for the three-by-three–lane roundabouts (three entry lanes and three circulating lanes) due to different traffic flow characteristics and features. This limitation of the Highway Capacity Manual 2010 model is also clearly mentioned in the manual. In this research, capacity models and curves were developed for three-by-three–lane roundabouts. More …

Potential Of Greywater Reuse And Its Effects On Potable Water Demand Management And Downstream Sewer Network, Muhammad Ashfaque Rajput Abdul Hameed

Theses

The UAE’s water demand is rapidly increasing because of population growth, infrastructure development, expansion of agricultural practices, and desert greening policies. These circumstances force the country to depend on expansive desalinated water and made the country the second-largest desalination water producer in the world. It is essential to reduce the current water consumption rates by using efficient methods and conservation techniques. Greywater reuse is an effective and promising alternative to cope with this challenge. The study aimed to reduce water consumption in the Emirate of Abu Dhabi by investigating the potential of greywater reuse. A field survey was carried out …

Structural Response Of Flexure-Deficient Reinforced Concrete Continuous Slabs Strengthened With Composites, Jwan Ahmad Al Khalil

Theses

Accidental reduction in the amount of steel in continuous reinforced concrete (RC) floor slabs is a typical problem that might occur due to an error in design, unclear drawings, or overlooked verification of reinforcement prior to concrete casting. Existence of such deficiencies would compromise the load capacity and serviceability of RC floor slabs. This research examines the effectiveness of using fiber-reinforced polymers (FRP) to improve the structural response of flexure-deficient continuous RC slab strips. The study comprised experimental testing and finite element (FE) modeling. Sixteen two-span RC slab strips, 400 x 125 x 3800 mm each, were tested. Test parameters …

Potential Of Greywater Reuse And Its Effects On Potable Water Demand Management And Downstream Sewer Network, Muhammad Ashfaque Rajput Abdul Hameed

Theses

The UAE’s water demand is rapidly increasing because of population growth, infrastructure development, expansion of agricultural practices and for the desert greening policies. These circumstances force the country to depend on expansive desalinated water and made the country second largest desalination water producer in the world. It is essential to reduce the current water consumption rates by using efficient methods and conservation techniques. Greywater reuse is an effective and promising alternate to cope with this challenge. The study aimed to reduce the water consumption in the Emirate of Abu Dhabi by investigating the potential of greywater reuse. A field survey …

Assessment Of Multi-Story Building Seismic Design Factors With Structural Irregularity, El Sayed Abdel Naby Abdel Aziz Abou Khalifa

Theses

Many high-rise buildings are practically irregular as a result of the architectural and service requirements in the design process, errors and modifications during the construction phase, and changes of the building use throughout its service life. Structural irregularities could increase the uncertainties related to the ability of the building to meet the design objectives. This study is thus devoted to assess the safety margins and calibrate the seismic design response factors of modern high-rise buildings with different vertical irregularity features. A brief survey of the most common vertical irregularities in reinforced concrete multi-story buildings is conducted to select reference structures. …

Assessment Of Multi-Story Building Seismic Design Factors With Structural Irregularity, El Sayed Abdel Naby Abdel Aziz Abou Khalifa

Theses

Many high-rise buildings are practically irregular as a result of the architectural and service requirements in the design process, errors and modification during the construction phase, and changes of the building use throughout its service life. Structural irregularities could increase the uncertainties related to the ability of the building to meet the design objectives. This study is thus devoted to assess the safety margins and calibrate the seismic design response factors of modern high-rise buildings with different vertical irregularity features. A brief survey of the most common vertical irregularities inn reinforced concrete multi-story buildings is conducted to select reference structures. …

Development Of Simulation-Based Fragility Relationships For The Seismic Risk Assessment Of Buildings, Anas Salem (Mohammad Ghaleb) Issa

Theses

A number of driving engines are required for earthquake loss estimation and mitigation, including an inventory of exposed systems, seismic hazards of the study area and fragility relationships. The number of existing buildings in the UAE that may be at risk because of insufficient seismic design provisions cannot be underestimated. A crucial role in the recovery period following an earthquake is also played by emergency facilities. Therefore, a systematic seismic vulnerability assessment of a diverse range of reference structures representing pre-seismic code buildings and emergency facilities, in a highly populated and seismically active area in the UAE, has been conducted …

Retrofitting Of Shear-Deficient Reinforced Concrete T-Girders With Composite-Based Systems, Alaa Ahmad Ata Maali

Theses

This research examines the viability of using different composite-based systems to upgrade the shear resistance of shear-deficient reinforced concrete T-girders. The research comprised experimental testing and analytical investigation. Test parameters included the retrofitting system; externally-bonded carbon fiber-reinforced polymer (EB-CFRP) laminates with or without a mechanical end anchorage (MA) and embedded through depth glass fiber-reinforced (ETD-GFRP) rebars; amount of internal stirrups; no stirrups, limited amount of stirrups with spacing s₁ = 0.6d, higher amount of stirrups with spacing s₂ = 0.375d; and initial shear damage prior to retrofitting; no damage, pre-cracking, and pre-failure.

The shear …

Flexural Behavior Of Reinforced Concrete T-Beams Strengthened With Nsm Composite System Under Accelerated Corrosion., Anes Bouchair

Theses

This research work aims at evaluating the effects of corrosion on flexural response of simply supported reinforced concrete (RC) T-Beams strengthened with near-surface-mounted carbon fiber-reinforced polymer (NSM-CFRP) strips. The research comprised experimental testing and analytical modelling. Test parameters included concrete grade, amount of NSM-CFRP strips, presence of U-wraps along the beam span, and time of corrosion exposure. A total of eighteen reinforced concrete beams with a T-shaped cross section were tested. Fourteen beams were strengthened in flexure and four beams were not strengthened to act as benchmarks. The strengthening regime included installation of either two or four NSM-CFRP strips into …