Engineering Commons^™

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, …

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, …

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 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, …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Performance Of Reinforced Concrete Beams Strengthened With Mechanically-Fastened Composite System Under Corrosive Environment, Amna Zaid Suwaid Al Nassibi

Theses

This study examines the effects of corrosion exposure on the flexural response of reinforced concrete (RC) beams strengthened with a powder-actuated fastened (PAF) composite system. Twenty-one RC beams were constructed and tested to failure under four-point bending. The corroded beams were subjected to 30, 60, and 100 days of accelerated corrosion that corresponded to measure tensile steel mass losses of 6, 11 and 18% respectively. Other test parameters included width of fiber reinforced polymer (FRP) composite strip, fastener length, and number of fasteners rows.

For the non-corroded beams, the PAF-FRP system resulted in up to 24% increase in beam flexural …

A Methodology To Consolidate Transit Stops For Enhancing Transit Users Travel Times, Mohammad Nurul Hassan

Theses

This study develops a methodology to consolidate transit stops. It develops a mathematical model and a program which takes stop consolidation decision(s) according to users travel time savings and desired accessibility. The model iterates until the users travels time savings are maximized. The study tests this mathematical model in different hypothetical scenarios. Six factors (distance between stops, passengers’ activity, average cruising speed, and maximum walkable distance, frequency of service and percentage of decreased passengers) with multiple levels were set to build the scenarios. Three responses (percentage of consolidated stops, percentage of travel time savings and percentage of operating …

Investigation Of The Mechanical Behavior Of I-Shaped Steel Beams Strengthened By Mechanically-Fastened Frp Laminates, Hothifa Nayef Rojob

Theses

Retrofitting and strengthening of steel structures have gained significant importance due to the highly increasing number of deteriorated steel structures in many places around the globe. The conventional method of retrofitting or strengthening of steel structures by replacing steel members or attaching additional external steel plates are usually time-consuming, corrodible, and a cumbersome task. Many of the drawbacks of the conventional retrofitting systems can be overcome through the use of Fiber Reinforced Polymers (FRP) due to their high strength-to-weight ratio. Furthermore, FRP materials are corrosion resistant, which makes them more durable especially when environmental deterioration is a concern. In recent …

Evaluation Of The Effectiveness Of Portable Variable Message Signs In Improving Safety For Motorists And Workers At Construction Zones In Abu Dhabi, Khalid Ismail Al-Zoubi

Theses

In March 2008, a single accident resulted in three people being killed and nearly 350 injured in a horrific crash involving over 60 vehicles on the Abu Dhabi-Dubai highway near Ghantoot. The cause of this crash was attributed to failure by motorists to adhere to severe weather conditions (fog). In response to the increasing number of accidents on Abu Dhabi roads, the Abu Dhabi Department of Transport (DoT) has deployed approximately 40 portable Variable Message Signs (PVMSs) throughout the main DOT's highway network as one of the strategies to control driver behavior and to improve road safety. The objective of …

Structural Performance And Economics Of High-Rise Buildings Under Seismic And Wind Loads, Nadeem Hussain

Theses

High-rise buildings have a priority when considering the potential consequences from natural hazards since they represent concentrated human and monetary assets. The use of high strength materials is promoted in this class of structures to effectively use floor areas, control vibrations and expedite construction. There is a pressing need to investigate the relationship between structural performance and economics of high-rise buildings with different material strengths under lateral loads, particularly seismic loads that control the design of a wide range of buildings.

To realistically represent the modern high-rise construction, five 60-story reinforced concrete (RC) buildings with varying material strengths, ranging from …

Strengthening Of Reinforced Concrete Beams Pre-Damaged In Shear, Yousef Mohammed Bachar Chekfeh

Theses

Repair and strengthening of existing reinforced concrete (RC) structures has increased drastically in recent years. Shear reinforcement in RC beams is typically of a small bar diameter, and hence any shear-damage would result in a severe safety hazard and a catastrophic mode of failure especially under extreme loading events. The present work was initiated to the effectiveness of different composite strengthening systems; namely externally bonded carbon fiber reinforced polymer (EB-CFRP), and near surface mounted glass fiber reinforced polymer (NSM-GFRP) to prolong the functional service life of RC beams pre-damaged in shear. It comprised experimental testing and analytical investigation.

The experimental …

Strengthening Of Steel Beams Using Mechanically Anchored Carbon Fiber Reinforced Polymers Laminates, Mohammed Monir Makin Ajan Alhadid

Theses

على مدى العقدين المنصرمين من الزمن تم إستخدام الألياف البلاستيكية المسلحة بشكل فعال و عملي في تقوية وتدعيم المنشأت الهندسية المختلفة بما في ذلك العناصر الإنشائية الخرسانية والطابوقية والخشبية, وطوال هذه الفترة الزمنية جرت أبحاث مفصلة حول العالم لدراسة مدى فاعلية مثل هذه الألياف في تقوية العناصر المعدنية و ذلك عن طريق تثبيتها بواسطة مواد شديدة الإلتصاقو ولقد كشفت الدراسات المنشورة أن هذه الطريقة في التثبيت سواءً في العناصر الخرسانية أو العناصر المعدنية تؤدي الي الانهيار الفجائي للعناصر المدعمة عند قيم التحميل المرتفعة ما لم يتم اتخاذ احتياطات أخرى وخصوصاً عند أطراف هذه الألياف، وبالمقابل فإن هناك دراسات أخرى أجريت …

Elasto-Plastic Lateral Torsional Buckling Of Steel Beams With Perforated Web, Mohammad Iqbal Mohammad Hesham Martini

Theses

I-shaped steel members represent the basic structural element in the majority of steel structures. Perforated-web I-shaped steel sections have been used as structural members since the Second World War in an attempt to enhance the flexural behavior of traditional solid-webbed I-shaped steel sections without increasing the cost of the material. In general, two types of web perforations are commonly used in engineering practice; hexagonal and circular. Although, the main intent of the perforation process is to produce stiffer I-sections by increasing the web height and providing higher major-axis flexural capacity than solid-webbed members of the same weight, it also provides …