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Item Conceptual Cost Estimation Models for Bridge Projects(North Dakota State University, 2021) Essegbey, Adikie EsinamConceptual cost estimating is typically completed early in the project lifecycle when little design work has been completed. Because little information is known at this early stage, the estimate usually deviates substantially from the actual construction cost. Therefore, the objective of this research is to develop a conceptual cost estimate model for bridge infrastructure projects. In this study, a systematic literature review and meta-analysis of Mean Average Percentage Errors (MAPEs) of cost models was undertaken to identify the various cost estimation methods, the input variables that have adopted in the development of models and determine the impact of cost estimation method on the accuracy of cost prediction. The research study utilized regression analysis, decision tree and random forest methods for cost prediction of Wisconsin bridges. A comparison of the three models that were developed revealed that random forest cost estimation method yielded better cost prediction.Item Studying Window Energy Performance Using Thermal Camera(North Dakota State University, 2020) Akbari, SevdaWindows, which are responsible for 45% of overall heat loss, play a major role in a building’s energy performance. Therefore, it is critical to measure window energy performance for existing buildings. This study aimed to evaluate the energy performance of windows to determine if replacement of windows is necessary. The evaluation was based on window location, height, orientation, and weather condition in a high-rise residential building. A thermal camera was used for measurements and statistical analyses were performed for measured data. Analysis results showed different performance of each side and floor of the building with a significant difference at the 0.05 level due to various temperatures, wind speeds, and directions. This study suggests using more efficient windows on upper floors, particularly from the fourth floor and above is beneficial as well as considering dominant wind speed and direction for the best configuration of window design.Item Conceptual Cost Estimation of Highway Bid Items Using Geostatistical Interpolation(North Dakota State University, 2021) Awuku, BrightChallenges associated with ensuring the accuracy and reliability of cost estimation of highway bid items, especially during the conceptual phase of a project, are of significant interest to state highway agencies. Even with the existing research undertaken on the subject, the problem of inaccurate estimation of highway bid items still exists. A systematic literature review was performed to determine research trends, identify, categorize the factors influencing highway unit prices, and assess the performance of conceptual cost prediction models. This research proposes a geographic information system (GIS)–based methodology that leverages vast historical bid data for unit-price estimation and the robust GIS capabilities with consideration of the effects of project-specific location and variations due to cost escalation on different bid items. A comparison of the three spatial interpolation techniques operationalized in this research revealed that disjunctive and empirical Bayesian kriging models led to more accurate cost prediction than ordinary kriging algorithms.Item Development of a High-Efficiency, Cost-Effective Ground Source Heat Pump System for Single-Family Houses(North Dakota State University, 2021) Hu, XiaoouMulti-Source Heat Pump systems are intended to achieve a high system efficiency through the combined or alternate use of two or more sources for a heat pump. This thesis entails the research work to develop a hybrid Ground Source Heat Pump (GSHP) system integrated with a dry cooler with vertical underground loops for single-family houses. TRNSYS is used to verify the feasibility of this integrated system, so as to optimize the control strategy and quantify the energy and energy cost savings. The primary objective is to demonstrate the improved system efficiency of the GSHP through the combined use of a dry cooler in a single-family house under the eight ASHRAE-defined climates. The results indicate that the integrated system would not be an optimal option for houses located in cold climates, but it is feasible to be implemented in hot/warm areas to increase system efficiency at low cost.Item Investigating the Effect of Temperature and Lighting on Learning Performance of Students Using Physiological Responses(North Dakota State University, 2022) Pradhan, SurakshyaTemperature and lighting level are relatively important parameters of indoor environment in a university classroom because they affect students' learning performance. Previous research primarily focused on analyzing students' learning performance, ignoring the learning process involved and the impact of physiological reactions to their learning environment. This study investigates the learning process as well as the influence of students' sensations/comfort and physiological responses. Experiments were carried out in a university classroom with 17 students performing cognitive tests while wearing an EEG headset and an ECG wristband at different temperatures (20-23°C, 23-26°C, 26-29°C) and lighting levels (100-300 lux, 300-600 lux,600-900 lux). The results showed brighter light improved concentration, while neutral temperature was important for working memory, and a comfortable environment and emotional state were important in increasing motivation for better learning performance. The findings can be used to develop an IEQ management plan that will contribute to improve the learning environment.Item Influence of Paste Quality Constituents on Drying Shrinkage(North Dakota State University, 2020) Affum, BenjaminThe paste system of concrete materials often holds the “DNA” to understanding their potential mechanical properties. As drying shrinkage and related cracking remains a top concern for the service life of concrete, this paper explores the effect of paste quality on drying shrinkage. The semi-adiabatic calorimetry, restrained, and unrestrained shrinkage of concrete made with 15 different cementitious materials were studied. Cementitious blends included fly ash, slag, silica fume, metakaolin, zeolite and limestone as paste volume was kept constant across mixes. Results showed that the rate at which the paste system allowed free water to dissipate at early ages may have dictated the extent of drying shrinkage. Higher cement replacement with limestone improved the tensile capacity of concrete which resulted in better drying shrinkage cracking resistance. High tricalcium aluminate and alkali contents in cements were found to be drivers of early age shrinkage and potential cracking at later stages in concreteItem Developing an Interactive Model to Integrate Human Expertise with Building Information Modelling (BIM) Software(North Dakota State University, 2022) Ahiable, CyrilConsidering the significant amount of time and money wasted yearly in fixing errors caused by miscommunication and inadequate information on project sites, relaying the knowledge of field experts through design software may reduce communication-based conflicts in projects. This study aimed at creating a model to integrate human field expertise in the construction process with BIM software and also explored strides made in a similar regard. The study also explored the various strides made in human expertise integration. Basement construction in Fargo-North Dakota was the construction scenario selected for scrutiny in this study. Surveys and in-person interviews were conducted with local contractors to ascertain valuable recommendations on basement construction in Fargo. Information from these contractors was validated and coded into two concept models to offer warnings and recommendations on the assessed basement construction activities to help Architecture, Engineering and Construction (AEC) professionals with construction processes required before and during construction.Item Environmental and Economic Outlook of Construction and Demolition Waste Management Practices in a Mid-Sized City(North Dakota State University, 2022) Boateng, Simon BoadiConstruction and demolition waste (CDW) left at landfill sites increases the burden on landfills, which are increasingly becoming scarce and costly to operate. In North Dakota, CDW generated is disposed of at the Fargo landfill. This practice may hamper the realization of value from construction and demolition waste. Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) was used to evaluate the benefits of two CDW management scenarios. The study found that a 75% reduction in the CDW sent to the landfill can reduce the environmental burden by 35%. Furthermore, replacing raw materials with recycled materials creates net environmental savings by preventing the production of raw or virgin materials. This practice can reduce the environmental burden by 25% while generating an income of $61/ton for the city. The results of this study provide information on the value of recycling CDW and serve as a basis for decision-makers to rethink CDW waste management practices in North Dakota.Item A Comparative Life Cycle Assessment Study of Wood and Steel Materials at Project End-of-Life Stage(North Dakota State University, 2021) Bi, BinThe disposal of construction and demolition waste will have an impact on the environment. However, the currently limited research on the end-of-life stage waste is too general lacking separation and comparison of different material types. This study focuses on the end-of-life stage to assess two primary construction materials (wood and steel) and an office building, used as a case study. This study is performed applying life cycle assessment (LCA) and used Athena software to assess the impact of both materials. The software quantifies the environmental impact of two materials into nine categories, including Global Warming Potential, Acidification Potential, etc. The results of this study show that steel generates more impact than wood on the environment. In the future, the results of this study can provide valuable information about the environmental impact of wood and steel materials to reduce the environmental impact at the end-of-life stage.Item Conceptual Cost Estimation of Highway Earthwork Construction in Iowa Using Spatial Statistical Modeling(North Dakota State University, 2022) Hitsanu, Martha SebsibeEstimating cost at the conceptual phase of highway earthwork construction projects is challenging owing to the limited amount of information present at the initial stages. Methods that have been applied in the past to perform such estimates are regression, mathematical equations, artificial intelligence, and others. The objective of this research is to use two spatial statistical methods – indicator kriging and empirical Bayesian kriging – together with exponential, whittle, and k-Bessel semi-variograms to build an appropriate model to predict highway earthwork construction cost at the conceptual stage. Iowa Department of Transportation provided the data for the study. The cross-validation results were used to compare the performance of the kriging algorithms. It was observed that the exponential semi-variogram showed better performance for both types of kriging when they were analyzed separately. However, indicator kriging results were more accurate than empirical Bayesian kriging when they were compared for the same type of semi-variogram.