Engineering Commons^™

Design, Construction, And Preliminary Investigations Of Otta Seal In Iowa, Sharif Y. Gushgari, Yang Zhang, Ali Nahvi, Halil Ceylan, Sunghwan Kim, Ali Arabzadeh, Charles T. Jahren, Charles Øverby

Ali Nahvi

Faced with limited financial resources, pavement engineers constantly seek more durable and economical technologies for road preservations and rehabilitations. Consequently, there have been many efforts to study resurfacing strategies, including various types of sealing for local roads. Among different sealing methodologies, Otta seal is a technique that has not yet been sufficiently studied in the U.S.A. For this investigation, the first Otta seal site in the state of Iowa was constructed using a double-layer Otta seal design over 6.4 km of cracked asphalt pavement. Otta seal design and construction details are documented and discussed, and test sections using various aggregates …

Polyurethane-Carbon Microfiber Composite Coating For Electrical Heating Of Concrete Pavement Surfaces, Alireza Sassani, Ali Arabzadeh, Halil Ceylan, Sunghwan Kim, Kasthurirangan Gopalakrishnan, Peter C. Taylor, Ali Nahvi

Ali Nahvi

Electrically-heated pavements have attracted attention as alternatives to the traditional ice/snow removal practices. Electrically conductive polymer-carbon composite coatings provide promising properties for this application. Based on the concept of joule heating, the conductive composite can be utilized as a resistor that generates heat by electric current and increases the surface temperature to melt the ice and snow on the pavement surface. This research investigates the feasibility of applying an electrically conductive composite coating made with a Polyurethane (PU) binder and micrometer-scale carbon fiber (CMF) filler as the electrical heating materials on the surface of Portland cement concrete (PCC) pavements. PU-CMF …

Simulation And Behavior Of Corrosion Deteriorated Reinforced Concrete Members, M. A. Shayanfar, Amir Safiey

Amir Safiey

Several reinforced concrete (RC) infrastructures are now crumbling from corrosion of steel bars in concrete. The paper presents the recent advancements in analytical simulation of corrosion aftereffects on behavior of RC members. The model juxtaposes the experimental findings with analytical relationships. The implementation of the model into a nonlinear finite element formulation as well as the experimental and analytical backgrounds are discussed. The abilities of the resulted program have been studied by modeling some experimental specimens showing a reasonable agreement between the analytical and experimental findings.

A New Approach For Nonlinear Finite Element Analysis Of Reinforced Concrete Structures With Corroded Reinforcements, Mohsen A. Shayanfar, Amir Safiey

Amir Safiey

A new approach for nonlinear finite element analysis of corroded reinforcements in reinforced concrete (RC) structures is elaborated in the article. An algorithmic procedure for producing the tension-stiffening curve of

RC elements taking into consideration most of effective parameters, e.g.: the rate of steel bar corrosion, bond-slip behavior, concrete cover and amount of reinforcement, is illustrated. This has been established on both experimental and analytical bases. This algorithm is implemented into a nonlinear finite element analysis program. The abilities of the resulted program have been studied by modeling some experimental specimens showing a reasonable agreement between the analytical and experimental …

A State-Of-The-Art Review Of Bending And Shear Behaviors Of Corrosion-Damaged Reinforced Concrete Beams, Mahmoodreza Soltani, Amir Safiey, Almarie Brennan

Amir Safiey

Steel corrosion is mainly at fault for the trend of deterioration among U.S. infrastructure—namely, bridges, pipelines, and wharves. Reinforced concrete (RC) is used as the primary construction material worldwide. Reinforcement corrosion can significantly impair mechanical properties of RC members, including shear and bending capacities. In the past decades, several attempts have been made to investigate the impacts of corrosion on the mechanical behavior of RC members. It can be observed that the number of research programs conducted on this topic has rapidly increased in recent years. Therefore, there is a need in the body of knowledge to encapsulate the relevant …

Investigation Of Corrosion Effects On Bond-Slip And Tensile Strength Of Reinforced Concrete Members, M. A. Shayanfar, Amir Safiey, M. Ghalehnovi

Amir Safiey

The corrosion effect on tensile strength of RC members is very important to region with high corrosion conditions. In this article a study on finding bond behaviour, crack pattern, crack spacing, and tensile strength of RC members is presented. For this purpose a comprehensive experimental program including reinforced concrete cylanders with different concrete covers and reinforcement ratios under various corrosion rates is conducted. The specimens are located in large tub containing water and salt (5% salt solution) with a devich for accelerated corrosion production. For each specimen, the variation of total tensile strength versus its average strain is plotted and …

Hypoelastic Modeling Of Reinforced Concrete Walls, Mohsen A. Shayanfar, Amir Safiey

Amir Safiey

This paper presents a new hypoelasticity model which was implemented in a nonlinear finite element formulation to analyze reinforced concrete (RC) structures. The model includes a new hypoelasticity constitutive relationship utilizing the rotation of material axis through successive iterations. The model can account for high nonlinearity of the stress-strain behavior of the concrete in the pre-peak regime, the softening behavior of the concrete in the post-peak regime and the irrecoverable volume dilatation at high levels of compressive load. This research introduces the modified version of the common application orthotropic stress-strain relation developed by Darwin and Pecknold. It is endeavored not …

Fiber Element-Based Nonlinear Analysis Of Concrete Bridge Piers With Consideration Of Permanent Displacement, Mokhtar Ansari, Farhad Daneshjoo, Amir Safiey, Naser Safaeian Hamzehkolaei, Maryam Sorkhou

Amir Safiey

Utilization of fiber beam-column element has gained considerable attention in recent years due mainly to its ability to model distributed plasticity over the length of the element through a number of integration points. However, the relatively high sensitivity of the method to modeling parameters as well as material behavior models can pose a significant challenge. Residual drift is one of the seismic demands which is highly sensitive to modeling parameters and material behavior models. Permanent deformations play a prominent role in the post-earthquake evaluation of serviceability of bridges affected by a near- fault ground shaking. In this research, the influence …

Corrosion Effects On Tension Stiffening Behavior Of Reinforced Concrete, M. A. Shayanfar, M. Ghalehnovi, Amir Safiey

Amir Safiey

The investigation of corrosion effects on the tensile behavior of reinforced concrete (RC) members is very important in region prone to high corrosion conditions. In this article, an experimental study concerning corrosion effects on tensile behavior of RC members is presented. For this purpose, a comprehensive experimental program including 58 cylindrical reinforced concrete specimens under various levels of corrosion is conducted. Some of the specimens (44) are located in large tub containing water and salt (5% salt solution); an electrical supplier has been utilized for the accelerated corrosion program. Afterwards, the tensile behavior of the specimens was studied by means …

Development Of Earthquake Vulnerability Functions And Risk Curves For Low And Mid-Rise Hotel Buildings Using A Performance-Based Loss Estimation Framework, Amir Safiey, Weichiang Pang, Mohammad Javanbarg, Keivan Rokneddin, Ershad Ziaei

AMIR SAFIEY

The concept of performance-based earthquake engineering has gained significant attentions in both the research and engineering communities. The development of a performance-based seismic loss assessment framework, known as the FEMA P-58 method, allows one to estimate the potential financial losses of a building using performance-based engineering method. This research employs a seismic loss estimation framework derived using the P-58 method to estimate the monetary loss of a mid-rise wood-frame hotel building which is assumed to be located in Napa Valley, California. A 3D structural model representative of the dynamic behavior of the wood-frame hotel was created and subjected to Incremental …

Transportation Safety Performance Of Us Bus Transit Agencies And Population Density: A Cross-Sectional Analysis (2008-2014), Ilker Karaca, Peter T. Savolainen

Ilker Karaca

The paper examines the transportation safety performance of transit agencies providing public bus service in the US by using data from the National Transit Database (NTD)

Uses NTD data for a seven-year period from 2008 to 2014 • 3,853 observations for 651 public transportation agencies in 50 states

Seven types of bus transit fatalities and injuries (including passengers, operators, pedestrians, bicyclists)

Main explanatory variable: urban density obtained from the US Census figures

Other explanatory variables: total agency revenue miles, unlinked passenger trips, agency fleet size, and urban population

Nchrp Synthesis 499: Alternate Design/Alternate Bid Process For Pavement-Type Selection. A Synthesis Of Highway Practice, Douglas D. Gransberg, Ashley F. Buss, Ilker Karaca, Michael C. Loulakis

Ilker Karaca

Highway administrators, engineers, and researchers often face problems for which information already exists, either in documented form or as undocumented experience and practice. This information may be fragmented, scattered, and unevaluated. As a consequence, full knowledge of what has been learned about a problem may not be brought to bear on its solution. Costly research findings may go unused, valuable experience may be overlooked, and due consideration may not be given to recommended practices for solving or alleviating the problem. There is information on nearly every subject of concern to highway administrators and engineers. Much of it derives from research …

Seismic Vulnerability Assessment Of Buildings Using A Statistical Method Of Response Prediction, Ershad Ziaei, Amir Safiey, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg, Mengzhe Gu

Amir Safiey

The seismic vulnerability functions for portfolio-level loss estimation are typically developed for general classes of buildings which may not be suitable to assess building-specific risks. Performance-based earthquake engineering (PBEE) provides the means to conduct building-specific seismic risk assessments. However, such assessments often rely on computationally-intensive analytical frameworks such as incremental dynamics analysis (IDA) which poses a challenge for many types of risk assessment projects. To expand its accessibility, FEMA P-58 outlines a simplified method to predict the nonlinear responses of buildings in which the scope is limited to lower levels of inter-story drifts (less than 4%). This limitation restricts its …

Influence Of Irreparability Fragility On Seismic Vulnerability Assessment Of Buildings, Amir Safiey, Ershad Ziaei, Mengzhe Gu, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg

Amir Safiey

The probability that a building is sanctioned to demolition following an earthquake depends on several geotechnical, structural, strategic and financial decision variables. This paper explores the literature on post-earthquake reparability assessment of buildings focusing on structural characteristics and evaluates their approaches for four midrise code-compliant structural systems, namely, steel moment frame, reinforced concrete moment frame, light frame wood, and steel braced frame. The structural responses are estimated using incremental dynamics analysis (IDA) in accordance with FEMA P-695 provisions and the IDA results are relayed to a building-specific loss assessment framework to estimate their seismic vulnerability in terms of monetary losses. …

Seismic Vulnerability Assessment Of Anchored Block Type Contents Due To Sliding And Overturning, Sereen Majdalaweyh, Weichiang Pang, Amir Safiey, Ershad Ziaei, Keivan Rokneddin, Mohammad Javanbarg, Saurabh Prabhu

Amir Safiey

Damage to contents and nonstructural components is often the main driver of property losses against smaller earthquakes as evidenced by empirical evidence from past events. In the 2014 South Napa earthquake in California, for example, 56% of the affected buildings reported content damage. The primary modes of content damage include sliding, rocking, and overturning. The FEMA P-58 document provides seismic fragility functions for sliding and overturning of unanchored block content types, but no data is provided for anchored components. The ASCE/SEI 7-16 provides stability guidelines for different types of nonstructural components, but falls short of providing recommendations for the contents …

Analytical Content Vulnerability Assessment Methodology For Earthquake Catastrophe Models, Keivan Rokneddin, Amir Safiey, Mohammad Javanbarg, Vijay Manghnani, Weichiang Pang

Amir Safiey

The scarcity of detailed claims data for building contents (Coverage C) from historical earthquake events poses a significant challenge for property insurance catastrophe models to reliably estimate the losses associated to building contents. To develop content vulnerability functions empirically, one would need to have access to data from a multitude of historical events; however, loss disaggregation by coverage is rarely reported even when claims data become available from recent significant events such as Maule (2010) and Tohoku (2011). While damage to the building structure (Coverage A) can be estimated analytically using simulation-based fragility functions to amend sparse historical observations, the …

Development Of Earthquake Vulnerability Functions And Risk Curves For Low And Mid-Rise Hotel Buildings Using A Performance-Based Loss Estimation Framework, Amir Safiey, Weichiang Pang, Mohammad Javanbarg, Keivan Rokneddin, Ershad Ziaei

Amir Safiey

The concept of performance-based earthquake engineering has gained significant attentions in both the research and engineering communities. The development of a performance-based seismic loss assessment framework, known as the FEMA P-58 method, allows one to estimate the potential financial losses of a building using performance-based engineering method. This research employs a seismic loss estimation framework derived using the P-58 method to estimate the monetary loss of a mid-rise wood-frame hotel building which is assumed to be located in Napa Valley, California. A 3D structural model representative of the dynamic behavior of the wood-frame hotel was created and subjected to Incremental …

Valuation Of Flexibility And Investment Timing In Airport Infrastructure Projects: Cases In Airport Expansions And Alternate Design Alternate Bid Bidding, Ilker Karaca

Ilker Karaca

Many large infrastructure projects are subject to considerable uncertainty over their revenue streams which makes their valuations particularly challenging. When project scalability can be altered as new information is revealed over the course of a project’s lifecycle, the presence of uncertainty can, in fact, provide option values that are ignored with static Net Present Value (NPV) analyses. To achieve these benefits, however, a better understanding of volatility is of the essence. This dissertation seeks to demonstrate how a better understanding of the business risks could facilitate the valuation of flexibility options in investment timing and engineering design. It also details …

A Review Of Pesticide Fate And Transport Simulation At Watershed Level Using Swat: Current Status And Research Concerns, Ruoyu Wang

Ruoyu Wang

Strengthening Of Continuous-Span Composite Bridges Using Post-Tensioning And Superimposed Trusses , Hisham Ahmed El-Arabaty

Hisham Ahmed

The need for upgrading understrength bridges in the United States has been well documented in the literature. In this thesis, two methods of strengthening are presented: post-tensioning of the positive moment regions of the bridge stringers and the addition of superimposed trusses at the piers. The use of these two systems is an efficient method of reducing flexural overstresses in undercapacity bridges. The objective of the research described in this thesis was to develop a design methodology to assist bridge engineers with designing a strengthening system to obtain the desired stress reductions. In addition, one such strengthening system was designed …

Nitrate Runoff Contributing From The Agriculturally Intensive San Joaquin River Watershed To Bay-Delta In California, Ruoyu Wang

Ruoyu Wang

Environmental Fate And Impact Assessment Of Thiobencarb Application In California Rice Fields Using Ricewq, Ruoyu Wang

Ruoyu Wang

Investigation Of The Effect Of Vehicle Color On Safety, Deogratias Eustace, Fayez Khalaf Alanazi, Peter W. Hovey

Peter Hovey

No abstract provided.

Investigation Of The Effect Of Vehicle Color On Safety, Deogratias Eustace, Fayez Khalaf Alanazi, Peter W. Hovey

Deogratias Eustace

No abstract provided.

Modeling Socio-Economic Determinants Of Traffic Fatalities, Amin Azimian, Deogratias Eustace

Deogratias Eustace

Over several decades, traffic growth has caused an increased number of traffic crashes, which are associated with economic losses and human sufferings. According to the National Highway Traffic Safety Administration [1] in 2016 there were a total of 34,247 fatal traffic crashes in the United States that resulted into 37,133 fatalities. Risk factors relating to the occurrence of fatal and injury severity of motor vehicle crashes have been extensively studied. Most studies [2-7] that have attempted to model the occurrences of traffic crashes and fatalities have been mainly confined to factors related to driver characteristics, roadway geometry characteristics, traffic characteristics, …

Wastewater Pipe Consequence Of Failure Model For Risk-Based Asset Management Using Analytic Hierarchy Process, Greta Vladeanu, John Matthews

John C. Matthews

Feasibility Investigation Of Upgrading Gravel Road To Otta Seal Surface: An Economic Analysis Approach, Ali Nahvi, Yang Zhang, Ali Arabzadeh, Halil Ceylan, Sunghwan Kim, Charles T. Jahren, Douglas D. Gransberg, Sharif Y. Gushgari

Ali Nahvi

The Norwegian Road Authorities desired that a surface treatment be cost-effective to provide a faster return on investment, perform (as perceived by the road user) in a manner similar to conventional bituminous surfacing, and comply with the following requirements: • Be cheap and easy to implement • Utilize locally-available aggregates • Be impervious to prevent water incursion into moisture-susceptible base material • Be very flexible, durable, and easy to maintain.

Such a bituminous surface treatment, referred to as in 1963, and initial field trials were carried out during 1963-1965 in the Otta Valley, Norway. Although Nordic countries, Asia, Africa, New …

Otta Seal Construction For Asphalt Pavement Resurfacing, Sharif Y. Gushgari, Yang Zhang, Ali Nahvi, Halil Ceylan, Sunghwan Kim

Ali Nahvi

Otta seal resurfacing methods have been widely demonstrated for unpaved roads and road rehabilitation in a few states in the U.S. as well as in Scandinavia and Africa. Application of Otta seal over a deteriorated hot mix asphalt (HMA) surface has been considered as the feasible concept that has not been applied for real construction. In this study, a double-layer Otta seal construction over HMA surface was monitored. The applied materials for the construction were introduced. The following performance of the constructed Otta seal layers was evaluated by measuring the international roughness index (IRI) and dust. The road IRI did …

Multi-Objective Bayesian Optimization Of Super Hydrophobic Coatings On Asphalt Concrete Surfaces, Ali Nahvi, Mohammad Kazem Sadoughi, Ali Arabzadeh, Alireza Sassani, Chao Hu, Halil Ceylan, Sunghwan Kim

Ali Nahvi

Conventional snow removal strategies add direct and indirect expenses to the economy through profit lost due to passenger delays costs, pavement durability issues, contaminating the water runoff, and so on. The use of superhydrophobic (super-water-repellent) coating methods is an alternative to conventional snow and ice removal practices for alleviating snow removal operations issues. As an integrated experimental and analytical study, this work focused on optimizing superhydrophobicity and skid resistance of hydrophobic coatings on asphalt concrete surfaces. A layer-by-layer (LBL) method was utilized for spray depositing polytetrafluoroethylene (PTFE) on an asphalt concrete at different spray times and variable dosages of PTFE. …

Evaluation Of Select Sensors For Real-Time Monitoring Of Escherichia Coli In Water Distribution Systems, Syreeta L. Miles, Ryan G. Sinclair, Mark R. Riley, Ian L. Pepper

Ryan Sinclair PhD, MPH

This study evaluated real-time sensing of Escherichia coli as a microbial contaminant in water distribution systems. Most sensors responded to increased E. coli concentrations, showing that select sensors can detect microbial water quality changes and be utilized as part of a contaminant warning system.