Construction Engineering and Management Commons^™

Recent Developments In Timber Design & Its Impact On Carbon Emissions, Raquel Jackson

Spectra Undergraduate Research Journal

This paper explores recent developments in timber building designs and its potential towards reducing carbon emissions. Carbon dioxide emissions are a growing issue worldwide as urbanization and industrialization continues to increase. The rising concentration of carbon dioxide emissions pose significant concerns towards public welfare and environmental health. Despite current methods to reduce greenhouse gasses, carbon emissions remain difficult to reduce from steel and concrete industries. Increasing timber use in building design is a possible solution. Increasing more timber in building design can help reduce carbon emissions due to the carbon-absorbing properties of the construction material. Timber as a construction material …

Cutting-Edge Technologies To Achieve A Higher Level Of Modular Construction – Literature Review, Seungtaek Lee, Jin Ouk Choi, Seung Song

Civil and Environmental Engineering and Construction Faculty Research

Cost overruns, schedule delays, and a shortage of skilled labor are common problems the construction industry is currently experiencing. Modularization and standardization strategies have the potential to resolve the various problems mentioned above and have been applied for various construction applications for a long time. However, the level of modularization remains low, and modular construction projects have not been getting the full benefits. Thus, this review investigated the cutting-edge technologies currently being utilized to develop the modular construction field. For this paper, qualified research papers were identified using predetermined keywords from previous related research papers. Identified literature was then filtered …

Hands-On Education Module For Modular Construction, 3d Design, And 4d Schedule, Kyle A. Kithas, Jin Ouk Choi

Architecture Faculty Research

A paradigm shift in teaching modular construction in higher education and K-12 is proposed as a means to increase the future adoption of the modular construction technique. To this effect, a new education module is presented to STEM educators. This education module is based on LEGOs and directed towards educators in the architecture, engineering, and construction (AEC) industry. The main objectives of the education module are to increase interest and knowledge of modular construction, acknowledge the benefits of using 3D design with 4D scheduling, and create a simulating hands-on educational opportunity. The education module is designed to allow participants to …

The Current State And Future Directions Of Industrial Robotic Arms In Modular Construction, Seung Ho Song, Jin Ouk Choi, Seungtaek Lee

Civil and Environmental Engineering and Construction Faculty Research

Industrial robotic arms are widely adopted in numerous industries for manufacturing automation under factory settings, which eliminates the limitations of manual labor and provides significant productivity and quality benefits. The U.S. modular construction industry, despite having similar controlled factory environments, still heavily relies on manual labor. Thus, this study investigates the U.S., Canada, and Europe-based leading modular construction companies and research labs implementing industrial robotic arms for manufacturing automation. The investigation mainly considered the current research scope, industry state, and constraints, as well as identifying the types and specifications of the robotic arms in use. First, the study investigated well-recognized …

Lessons Learned During The Early Phases Of A Modular Project: A Case Study Of Unlv's Solar Decathlon 2020 Project, Jin Ouk Choi, Seungtaek Lee, Eric Weber

Civil and Environmental Engineering and Construction Faculty Research

The U.S. Department of Energy conducts the Solar Decathlon competition as a student-based achievement that encourages sustainable design with energy efficiency and solar energy technologies. In the 2020 competition, the University of Nevada, Las Vegas (UNLV) team designed, fabricated, and constructed a net-zero modular house that applies innovative and highly efficient building technologies. This paper focused on the lessons learned during the early phases of this ongoing modular project. The research methodology included obtaining feedback from key project participants using a well-structured questionnaire. The results showed that the major items/challenges in the project’s planning phase included selecting the modular size, …

Improving Active Learning Through Advanced Teaching Practices On An Online Course, Jin Ouk O. Choi

UNLV Best Teaching Practices Expo

Since the outbreak of the COVID, there has been a great need to advance learning experiences and opportunities for students when the courses are taught remotely. To address the need, the author incorporated the teaching strategies learned from the Culturally Relevant & Responsive Teaching (CRRT) fellows program supported by the NSF TRANSCEnD project. In Fall 2021, the author implemented multiple new teaching techniques and strategies in the CEM453-653 course, delivered entirely online. The specific teaching practices and technologies are: 1) Delivering lectures both live (synchronous) and recordings (asynchronous); 2) Using adaptive technology (Mentimeter & WebEx Poll) with real-time feedback; 3) …

Construction Disputes And Associated Contractual Knowledge Discovery Using Unstructured Text-Heavy Data: Legal Cases In The United Kingdom, Jeehee Lee, Youngjib Ham, June-Seong Yi

Civil and Environmental Engineering and Construction Faculty Research

Construction disputes are one of the main challenges to successful construction projects. Most construction parties experience claims—and even worse, disputes—which are costly and time-consuming to resolve. Lessons learned from past failure cases can help reduce potential future risk factors that likely lead to disputes. In particular, case law, which has been accumulated from the past, is valuable information, providing useful insights to prepare for future disputes. However, few efforts have been made to discover legal knowledge using a large scale of case laws in the construction field. The aim of this paper is to enhance understanding of the multifaceted legal …

Collective Risk Of Construction Development On Desert Tortoise Populations, Paulina Smith

Undergraduate Research Symposium Posters

Desert tortoises (Gopherus agassizii) are threatened, extremely territorial reptiles living on a rapidly-shrinking landscape. This literature review was conducted with the goal of determining whether the desert tortoises of the Mojave Desert are experiencing compounded effects from construction development which are not reflected in mortality/fecundity calculations in the current literature. Seventeen peer-reviewed sources were identified from the last 20 years which related to roads, railroads, wind-harvesting, solar energy, and man-made barriers/flood control centers in the Mojave. Current literature reveals that researchers do not have the time nor resources to pursue long-term studies on all of the possible effects on this …

An Experimental Study On Concrete’S Durability And Mechanical Characteristics Subjected To Different Curing Regimes, Edgar L.S. Borrero, Visar Farhangi, Kazem Jadidi, Moses Karakouzian

Civil and Environmental Engineering and Construction Faculty Research

Considering a constant demand in construction of concrete structures to develop novel approaches for predicting the concert’s properties, a host of investigations were performed on concrete’s mechanical properties and durability under various curing regimes. However, few studies were concerned with evaluating the concrete’s durability using non-destructive concrete surface resistivity tests by applying various curing conditions. The present study compares the influence of different curing regimes on durability and compressive strength of concrete to recommend the most effective curing conditions on concrete’s characteristics. Five curing conditions including ambient, laboratory, dry oven, wet oven and 7-days were analyzed. Accordingly, a non-destructive concrete …

Mechanical Characteristics Of Cement Paste In The Presence Of Carbon Nanotubes And Silica Oxide Nanoparticles: An Experimental Study, Moses Karakouzian, Visar Farhangi, Marzieh R. Farani, Alireza Joshaghani, Mehdi Zadehmohamad, Mohammad Ahmadzadeh

Civil and Environmental Engineering and Construction Faculty Research

Considering the remarkable characteristics of nanomaterials, previous research studies investigated the effects of incorporating different types of these materials on improving the concrete properties. However, further studies are required to evaluate the complementary hybridization and synergistic influence of nanomaterials. In this research, the combined effect of adding nano silica particles (NS) and multi-walled carbon nanotubes (MWCNT) on enhancing both the compressive and flexural strengths of the cement paste was investigated. Moreover, the morphology of the interface between cement paste and aggregates was studied by scanning electron microscopy (SEM). The mixtures were prepared using three different portions of MWCNT and NS. …

Wearable Sensing Devices: Towards The Development Of A Personalized System For Construction Safety And Health Risk Mitigation, Chukwuma Nnaji, Ibukun Awolusi, Jeewoong Park, Alex Albert

Civil and Environmental Engineering and Construction Faculty Research

Wearable sensing devices (WSDs) are increasingly helping workers stay safe and healthy in several industries. However, workers, especially in the construction industry, have shown some aversion towards the use of WSDs due to their ability to capture specific information that may be considered personal and private. However, this revered information may provide some critical insight needed by management to plan and optimize worksite safety and support technology adoption in decision making. Therefore, there is a need to develop personalized WSD systems that are mutually beneficial to workers and management to ensure successful WSD integration. The present study aims to contribute …

A Review Of Different Aspects Of Applying Asphalt And Bituminous Mixes Under A Railway Track, Kazem Jadidi, Morteza Esmaeili, Mehdi Kalantari, Mehdi Khalili

Civil and Environmental Engineering and Construction Faculty Research

Asphalt is a common material that is used extensively for roadways. Furthermore, bituminous mixes have been used in railways, both as asphalt and as mortar. Different agencies and research institutes have investigated and suggested various applications. These studies indicate the benefits of bituminous material under railways, such as improving a substructure’s stiffness and bearing capacity; enhancing its dynamic characteristics and response, especially under high-speed train loads; waterproofing the subgrade; protecting the top layers against fine contamination. These potential applications can improve the overall track structure performance and lead to minimizing settlement under heavy loads. They can also guarantee an appropriate …

Multi-Level-Phase Deep Learning Using Divide-And-Conquer For Scaffolding Safety, Sayan Sakhakarmi, Jee Woong Park

Civil and Environmental Engineering and Construction Faculty Research

A traditional structural analysis of scaffolding structures requires loading conditions that are only possible during design, but not in operation. Thus, this study proposes a method that can be used during operation to make an automated safety prediction for scaffolds. It implements a divide-and-conquer technique with deep learning. As a test scaffolding, a four-bay, three-story scaffold model was used. Analysis of the model led to 1411 unique safety cases for the model. To apply deep learning, a test simulation generated 1,540,000 datasets for pre-training, and an additional 141,100 datasets for testing purposes. The cases were then sub-divided into 18 categories …

Calibrating Cii Rt283s Modularization Critical Success Factor Accomplishments, Jin Choi, James T. O’Connor, Young Hoon Kwak, Rajarshi Ghimire

Civil and Environmental Engineering and Construction Faculty Research

Modularization is a well-known construction technique where sections of the job are moved from on-site to a fabrication shop. Previously, the researchers identified the 21 most influential Critical Success Factors (CSFs) for successful modularization and quantified the degree of each CSF’s accomplishment by conducting a survey with 19 subject matter experts, and a case study with three modular projects. Through this methodology, the findings relied on the experience of experts. However, still missing from the understanding of modularization CSFs is a validation of the current degree of each CSF’s accomplishment by examining actual modular projects using a sufficient number of …

Investigation Of Setting Time And Compressive Strength Of Ready-Mixed Concrete Blended With Returned Fresh Concrete, Negasi N. Gebremichael, S. Mahmoud Motahara Karein, Moses Karakouzian, Kazem Jadidi

Civil and Environmental Engineering and Construction Faculty Research

Returned fresh mix concrete (RFC) is a problem with both economic and environmental impacts. Therefore, investigators have recommended various ways to decrease the amount of RFC in manufacturing facilities. Among the most common procedures are dumping concrete in landfill, recycling it, using the aggregate, and using it to produce concrete blocks. In this study, the authors investigated the behavior of various proportions of RFC mixed with ready-mix plain and retarded concrete. The authors also studied the influence of aging by producing specimens after one, two, three, and four hours. In addition, the researchers investigated controlled and uncontrolled environments by mixing …

An Embedded Sensory System For Worker Safety: Prototype Development And Evaluation, Chunhee Cho, Jee Woong Park

Civil and Environmental Engineering and Construction Faculty Research

At a construction site, workers mainly rely on two senses, which are sight and sound, in order to perceive their physical surroundings. However, they are often hindered by the nature of most construction sites, which are usually dynamic, loud, and complicated. To overcome these challenges, this research explored a method using an embedded sensory system that might offer construction workers an artificial sensing ability to better perceive their surroundings. This study identified three parameters (i.e., intensity, signal length, and delay between consecutive pulses) needed for tactile-based signals for the construction workers to communicate quickly. We developed a prototype system based …

Hispanic Construction Workers And Assertiveness Training, Pramen Shrestha, Nancy Menzel

Nursing Faculty Publications

BACKGROUND: Hispanic (Latino) construction workers experience disparities in occupational death and injury rates in the United States. The cultural value of respect for those in authority may hinder these workers from requesting safe working conditions from supervisors.

OBJECTIVE: To evaluate whether Hispanic construction workers in Las Vegas, Nevada found assertiveness training more useful than non-Hispanic trainees and whether or not they practiced this behavior at work after the training.

METHODS: An assertiveness training simulation was part of fall prevention classes offered to area construction workers. Eight weeks after the training, participants were interviewed by telephone about class topics they found …

Mechanical And Transport Properties Of Alkali-Activated Natural Pozzolans As Sustainable Binders, Brittany Radke

Calvert Undergraduate Research Awards

OPC production accounts for 5 to 7% of the global carbon dioxide (CO₂) emissions, contributing to global warming. The desire to reduce CO₂ emissions and produce more durable concrete has given impetus to search for new binders. It is suggested that alkali-activated natural pozzolans have the potential for use as a sustainable replacement for OPC in concrete.

The current study presented herein evaluated fresh, mechanical, and transport properties of alkali-activated natural pozzolan mortars containing various concentrations of sodium hydroxide solutions as an alkaline activator. To this aim, alkali-activated natural pozzolan mortars were made with concentrations of sodium …

Evaluation Of Alternative Project Delivery Methods In Water And Wastewater Projects, Ruiko Maharjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The United States (U.S.) is facing significant challenges in addressing aging water infrastructure. Most of the drinking water infrastructure is reaching the end of their useful lives. The American Water Works Association (AWWA) estimated that it will cost about $1 trillion to repair or replace drinking water pipes. Over the next 20 years, it will cost about $298 billion to fix or expand pipes of the nation's wastewater and storm-water systems (AWWA, 2012). Owners, engineers, and contractors are using Alternative Project Delivery (APD) methods - e.g., Design-Build Construction Management-at-Risk Construction Management/General Contractor- to build water and wastewater projects in order …

Performance Comparison Of Design-Build And Construction Manager/General Contractor Highway Projects, Binita Shakya

UNLV Theses, Dissertations, Professional Papers, and Capstones

Researchers have conducted numerous studies comparing project performance of design-bid-build (DBB) and design-build (DB) highway projects. However, little research has been done to compare the performance of DB and construction manager/general contractor (CM/GC) highway projects. Therefore, an exploratory study was conducted to compare the performance of 55 DB and 34 CM/GC highway projects from various States Departments of Transportation (DOTs) in terms of cost, change orders, and construction intensity. The results showed that contract award cost growth was significantly lower in DB projects than in CM/GC projects. In contrast to this, the total cost growth of DB projects was higher …

A Comparative Study Of Performance, Impediments, Advantages, And Disadvantages Of Construction And Professional Disadvantaged Business Enterprises, Ravi Sharma

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction and professional disadvantaged, minority, and women business enterprises (DBE/MBE/WBEs) face several impediments that hinder their business growth. A questionnaire survey was conducted to determine the important factors that affect their business performance, impediments faced by these business enterprises, advantages, and disadvantages of being DBE (DBE will be an umbrella designation for DBE, MBE, and WBE). This study compares the difference in responses from these two groups. A total of 333 business enterprises responded to the questionnaire. The survey results showed that construction firms gave significantly higher importance to "financial" issues and "safe work practices" as their most important factors …

Vulnerability Of Progressive Collapse In Reinforced Concrete Flat-Plate Buildings, Jinrong Liu

College of Engineering: Graduate Celebration Programs

• Progressive collapse is the spread of initial local failure, causing partial or
  even total collapse of a building.
• Flat plate structure is widely used for office and residential buildings.
• There is a large inventory of older flat plate building without continuous slab bottom reinforcement through columns.
• Limited knowledge exists regarding the risk of disproportionate collapse in
  older flat-plates under sudden column removal during abnormal events.
• Reliable mechanical model is needed for structural evaluation.

Legal Issues In Green Construction, Namrata Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

The most recent "green construction movement", made a significant impact on the design and construction industry in the United States. Organizations such as the American Institute of Architects (AIA) have lobbied governmental entities to provide financial incentives to promote green construction. The green construction community also promotes the notion that a healthier working and living environment is achieved. Due to finical incentives coupled with projected long-term energy cost savings, many owners of new construction are considering green construction as an option. Accompanying the "green construction movement", new kinds of legal issues, particularly relating to green aspects such as certification, energy …

Framework Development For Construction Safety Visualization, Kishor Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Throughout the history of the construction industry, many fatalities and injuries have occurred in construction sites. One of the major causes of accidents is unsafe site conditions; basically, this is due to inadequate supervision. To improve upon the traditional supervision approach, this study proposes a `Framework Development for Construction Safety Visualization' approach. In addition to this, a computer vision Edge Detection Algorithm was developed and tested to convert construction site still images into edges of the objects in the images. The framework development of this study uses computer vision, robot vision, image compression, pattern recognition, internet transmission, network communication, and …

Framework Developmant For Construction Safety Visialization, Kishor Shrestha

College of Engineering: Graduate Celebration Programs

Throughout the history of the construction industry, many fatalities and injuries have occurred in construction sites. One of the major causes of accidents is unsafe site conditions: basically, this is due to inadequate supervision. To improve upon the traditional supervision approach, this study proposes a 'Framework Development for Construction Safety Visualization' approach. In addition to this, a computer vision Edge Detection Algorithm was developed and tested to convert construction site still images into edges of the objects in the images. The framework development of this study uses computer vision, robot vision, image compression, pattern recognition, internet transmission, network communication, and …

Fall Prevention Training And Its Impact To Southern Nevada Construction Workers, Vedaspati Joshi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Death and injury from falls are a long-standing and continuing problem in construction, responsible for at least a third of the construction deaths in the U.S. from 2004 to 2007. Each of those years, Nevada has exceeded the national percentage. Although 29 CFR 1926.503 sets forth Occupational Safety and Health Administration (OSHA)'s requirements that construction employers train employees exposed to fall hazards and document such training, the incidence of deaths and injuries from falls are an indicator that this training was not provided or else was not effective.

Conventional fall protection training is more narrowly focused on recognizing fall hazards …

Comparison Of Design-Build And Design-Bid-Build Performance Of Public University Projects, James David Fernane

UNLV Theses, Dissertations, Professional Papers, and Capstones

With an unsure market and scarce work, owners across the United States, especially universities, are finding themselves in situations where they are unable to complete their projects within cost and schedule using the traditional delivery method: Design-Bid-Build (DBB). Under the DBB project delivery method, many competent contractors are electing to send low bids on projects just to keep work on their books, with plans to receive change orders once the project is underway; this practice is leading to cost and schedule overruns. Public universities across the United States are beginning to elect to use Design-Build (DB) as an alternate project …

Recycling Waste Latex Paint In Overlays, Rigid Pavements, And Pervious Concrete, Oscar Inez Quiroz

UNLV Theses, Dissertations, Professional Papers, and Capstones

With over 16 million gallons of latex paint (WLP) being disposed every year it is the largest by volume, liquid hazardous waste in the United States. WLP is difficult to recycle and hazardous to the environment due to the volatile organic compounds it contains. Several methods exist for disposing WLP including paint swaps, combustion, drying and discarding in a landfill, and by placing pigments in cement. Many communities are moving to dispose WLP by drying and placing in a landfill due to the reduced cost. However, this is the least preferred technique for the environment because it creates a need …

Impact Of Design Cost On Project Performance Of Design Bid Build Projects, Nirajan Mani

UNLV Theses, Dissertations, Professional Papers, and Capstones

The majority of public projects in the United States are procured and constructed by state or local governments using the design-bid-build (DBB) project delivery method. In the DBB method, the detailed design is completed by a design firm, then, a contractor builds the project according to the plans and specifications prepared by the design firm. Some studies show that a project's performance depends upon the quality of the design. If the errors in a design are minimized, the construction cost and schedule growth of the project also will be minimized.

This study analyzed data from Clark County, Nevada public works …

Performance Of Nevada’S Aggregates In Alkali-Aggregate Reactivity Of Portland Cement Concrete, Mohammad Shahidul Islam

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alkali-aggregate reaction (AAR) is a form of distress that occurs in concrete and results in serviceability problems, cracks, spalling, and other deterioration mechanisms. There are two categories of AAR, namely, alkali-silica reaction (ASR) and alkali-carbonate reaction (ACR). Alkali-silica reaction is one of the most recognized deleterious phenomena in concrete, and has been a major concern since its discovery in the 1940s. The reaction which occurs between reactive silica or silicates present in some aggregates and alkalis of Portland cement produces an alkali-silica gel that expands in the presence of moisture resulting in concrete cracks. ACR is also a chemical reaction …