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Full-Text Articles in Engineering

A System Dynamics Approach For Study Of Population Growth And The Residential Housing Market In The Us, Gasser Galal Ali, Islam H. El-Adaway, Cihan H. Dagli May 2020

A System Dynamics Approach For Study Of Population Growth And The Residential Housing Market In The Us, Gasser Galal Ali, Islam H. El-Adaway, Cihan H. Dagli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The US Consensus bureau estimated the total construction spending at 1,320,305 Million Dollars, in February 2020, with an increase of 1.1% since last February. The construction market is large, and risky. Prediction of the market behavior, for several years ahead, is needed in order to take strategic investment decision for long and expensive projects. The goal of this research is to study the relationship between population growth and the housing market. To that end, a system dynamics model is developed. System dynamics is a top-down approach that starts with the high-level behavior of a complex system to simulate the behavior …


A System-Of-Systems Model To Simulate The Complex Emergent Behavior Of Vehicle Traffic On An Urban Transportation Infrastructure Network, Rayan Assaad, Cihan H. Dagli, Islam H. El-Adaway May 2020

A System-Of-Systems Model To Simulate The Complex Emergent Behavior Of Vehicle Traffic On An Urban Transportation Infrastructure Network, Rayan Assaad, Cihan H. Dagli, Islam H. El-Adaway

Engineering Management and Systems Engineering Faculty Research & Creative Works

Transportation agencies face escalating challenges in forecasting the traffic demand. Traditional prediction methods focused on individual transportation sectors and failed to study the inter-dependencies between the different transportation systems. Hence, there is a need for more advanced and holistic modeling techniques. To this end, this paper models and analyses an urban transportation system-of-systems incorporating seven various systems: population and GDP, CO2 emission, gasoline price and total vehicle trips, traffic demand, public and private transportation, transportation investment, and traffic congestion. Accordingly, this research simulates transportation networks as a collection of task-oriented systems that combine their resources to form a complex …


An Agent-Based Model To Study Competitive Construction Bidding And The Winner's Curse, Amr Elsayegh, Cihan H. Dagli, Islam H. El-Adaway May 2020

An Agent-Based Model To Study Competitive Construction Bidding And The Winner's Curse, Amr Elsayegh, Cihan H. Dagli, Islam H. El-Adaway

Engineering Management and Systems Engineering Faculty Research & Creative Works

Reverse auction theory is the basis for competitive construction bidding process. The lowest bid method is utilized for selecting contractors in public projects. The winning contractor having the lowest bid value could be cursed when the submitted bid value results in negative profits. This is caused by many factors such as the contractor's estimation accuracy and markup. This is addressed in this paper by providing a model simulating the construction competitive bidding and the occurrence of the winner's curse. To this end, the authors show the extent to which the winner's curse affects the status of contracting companies. The objectives …


A System Dynamics Model For Construction Safety Behavior, Mohamad Abdul Nabi, Islam H. El-Adaway, Cihan H. Dagli May 2020

A System Dynamics Model For Construction Safety Behavior, Mohamad Abdul Nabi, Islam H. El-Adaway, Cihan H. Dagli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Construction Industry has always been reputed by its high incident rates and poor safety performance. Construction accidents are, in most cases, resulted from the unsafe behaviors of construction workers on site. The study of workers' behavior is crucial in order to understand the causation of unsafe behaviors. Therefore, the objective of this paper is to simulate construction safety behavior in order to predict the number of safety incidents and better understand their causation factors. The simulation model illustrates how construction system influences construction labors on site in terms of unsafe behavior. The standard leading indicators of safety performance are first …


Understanding Transport Of An Elastic, Spherical Particle Through A Confining Channel, Shuaijun Li, Honghui Yu, Tai-De Li, Zi Chen, Wen Deng, Alimohammad Anbari, Jing Fan Mar 2020

Understanding Transport Of An Elastic, Spherical Particle Through A Confining Channel, Shuaijun Li, Honghui Yu, Tai-De Li, Zi Chen, Wen Deng, Alimohammad Anbari, Jing Fan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The transport of soft particles through narrow channels or pores is ubiquitous in biological systems and industrial processes. On many occasions, the particles deform and temporarily block the channel, inducing a built-up pressure. This pressure buildup often has a profound effect on the behavior of the respective system; yet, it is difficult to be characterized. In this work, we establish a quantitative correlation between the built-up pressure and the material and geometry properties through experiments and mechanics analysis. We fabricate microgels with a controlled diameter and elastic modulus by microfluidics. We then force them to individually pass through a constrictive …


A New Type Of Crumb Rubber Asphalt Mixture: A Dry Process Design And Performance Evaluation, Feng Ma, Jiasheng Dai, Zhen Fu, Jenny Liu, Wenhao Dong, Zhen Huang Jan 2020

A New Type Of Crumb Rubber Asphalt Mixture: A Dry Process Design And Performance Evaluation, Feng Ma, Jiasheng Dai, Zhen Fu, Jenny Liu, Wenhao Dong, Zhen Huang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To obtain a crumb rubber asphalt mixture with excellent performance, this study combined trans-polyoctenamer rubber (TOR), crumb rubber, and other additives to establish a new type of crumb rubber (CRT). The objective of this study was to design and evaluate the road performance of the new type of crumb rubber asphalt mixture (CRTAM) with a skeleton dense texture through a dry process. First, the skeleton intrusion compact volume method was used to optimize the grading of coarse and fine aggregates, and the design of the CRTAM gradation was carried out through the same and unequal volume replacement grading method. Then, …


Optical Fiber Based Integrity Test Of Civil Engineering Materials: Numerical Analysis, Ruoyu Zhong Jan 2020

Optical Fiber Based Integrity Test Of Civil Engineering Materials: Numerical Analysis, Ruoyu Zhong

Masters Theses

“Major advancement in Civil Engineering cannot be accomplished without the help of sensors. Among different types of sensors, fiber-optic sensor is known for its light weight, high accuracy, resolution, immunity to electromagnetic interference, and resistance to harsh environment. This research mainly focuses on fiber-optic sensor application on concrete structures as temperature sensor. Thermal Integrity Profiling (TIP) is a non-destructive integrity testing method which makes use of the hydration heat from the concrete curing process to detect defects within a drilled shaft. Any defect of concrete could result in a temperature anomaly in a drilled shaft. The accuracy of the current …


Studying The Effects Of Various Process Parameters On Early Age Hydration Of Single- And Multi-Phase Cementitious Systems, Rachel Cook Jan 2020

Studying The Effects Of Various Process Parameters On Early Age Hydration Of Single- And Multi-Phase Cementitious Systems, Rachel Cook

Doctoral Dissertations

”The hydration of multi-phase ordinary Portland cement (OPC) and its pure phase derivatives, such as tricalcium silicate (C3S) and belite (ß-C2S), are studied in the context varying process parameters -- for instance, variable water content, water activity, superplasticizer structure and dose, and mineral additive type and particle size. These parameters are studied by means of physical experiments and numerical/computational techniques, such as: thermodynamic estimations; numerical kinetic-based modelling; and artificial intelligence techniques like machine learning (ML) models. In the past decade, numerical kinetic modeling has greatly improved in terms of fitting experimental, isothermal calorimetry to kinetic-based modelling …


Seismic Behavior Of Composite Bridge Columns, Mohanad M. Abdulazeez Jan 2020

Seismic Behavior Of Composite Bridge Columns, Mohanad M. Abdulazeez

Doctoral Dissertations

“This study investigates experimentally and numerically the seismic behavior of large-scale hollow-core fiber-reinforced polymer-concrete-steel (HC-FCS) innovative bridge columns as a sustainable approach to endure and rapidly recover from natural disasters such as earthquakes. The HC-FCS column consisted of a concrete shell sandwiched between an outer fiber-reinforced polymer (GFRP) tube and an inner steel tube to provided continuous confinement for the concrete shell along with the height of the column. The columns have a slender inner steel tube with diameter-to-thickness (Ds/ts) ratios ranged between 85 to 254. Each steel tube was embedded into the footing, while the …


Minimizing The Negative Effect Of Pumping On Scc Freeze-Thaw Durability, Daniel Galvez-Moreno Jan 2020

Minimizing The Negative Effect Of Pumping On Scc Freeze-Thaw Durability, Daniel Galvez-Moreno

Doctoral Dissertations

“The durability of concrete must be ensured to reduce the carbon footprint of the production of portland cement. If concrete is properly designed to preserve its integrity under adverse exposure conditions, the service life of the material can be extended with minimum maintenance. Nevertheless, bad handling, placing, finishing or curing practices can abate the durability potential and service life of even the best mix design. Pumping concrete is a very efficient placing technique that offers significant cost reduction and versatility at the jobsite, but it also has the potential of altering the air void system parameters, which are key to …


Complexities Observed During The Development Of A Rheological Testing Procedure For Small Cement Paste Samples, Aida Margarita Ley-Hernandez Jan 2020

Complexities Observed During The Development Of A Rheological Testing Procedure For Small Cement Paste Samples, Aida Margarita Ley-Hernandez

Doctoral Dissertations

“Rheology has been widely used to describe the flow properties of fresh cement-based suspensions. The use of a rheometer to characterize these properties is not a straightforward task due to the dependency to different preparation conditions, mixing processes, testing procedures and measuring instruments employed. In addition, shear and time dependency of the material which undergoes chemical and physical particle bonding, caused by hydration of cement and flocculation. Nevertheless, the characterization and understanding of the rheological behavior of cement-based materials have become essential with the recent introduction of novel applications like digital construction in the field of civil engineering, among others. …


Feasibility Study On Novel Fire-Resistant Coating Materials, Anyou Zhu Jan 2020

Feasibility Study On Novel Fire-Resistant Coating Materials, Anyou Zhu

Masters Theses

“Over the past decades, wildfires in the United States have caused severe damage and property losses. The California Camp Fire in November 2018 caused 85 civilian fatalities and destroyed 18,793 structures. There is a need to enhance the fire resistance of structures and buildings. The primary purpose of this study was to develop innovative surface-bonded fire-resistant material that can be used as a wall coating with three primary features: (a) workability for application, (b) enough adhesion to the surface of the structure, (c) fire-resistant. This research developed mix designs of innovative fire-resistant coating materials including high-performance cement mortar (HPCM), geopolymer …


Bond Behavior Of Advanced Fiber Reinforced Composite-Concrete Joints, Xingxing Zou Jan 2020

Bond Behavior Of Advanced Fiber Reinforced Composite-Concrete Joints, Xingxing Zou

Doctoral Dissertations

“Externally bonding advanced composite materials to concrete structures is an effective way to improve their strength, ductility, and durability. The interfacial bond behavior is fundamental to understand the overall structural performance of concrete structures strengthened with advanced composite materials. This study includes a comprehensive investigation of the bond behavior of composite-concrete joints with different fiber reinforced composite types. First, a direct approach to determine the bond-slip relationship for fiber reinforced cementitious matrix (FRCM)-concrete joints based on fiber strain measurements was proposed. Then, an analytical solution to predict the full-range response of FRCM-concrete joints was derived by assuming a trilinear bond-slip …