Engineering Commons^™

Meta-Analysis Of Insulated Concrete Wall Panel Design Methods For Shear And Flexure Behavior, Maryam Al-Bayati

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

Insulated Concrete wall panels have been designed and constructed since the early 1950s with various shear ties, dimensions, and methods; nonetheless, thermal bridging and rational design are still a concern. Many companies have recently developed plastic connectors that have gradually replaced solid concrete sections and steel connectors due to their superior thermal efficiency and strength. However, there is no generally accepted method for predicting the behavior of sandwich wall panels in structural engineering practice or codes, but many methods have been used since the early 1920. This study aims to evaluate the accuracy of current methods for predicting the flexural …

Facilitating The Industrial Sector's Adoption Of Collaborative Project Delivery Methods, Xavier Wood-Aliberch

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

In an effort to improve outcomes in the civil and healthcare sectors, clients have adopted collaborative project delivery methods for the delivery of their capital projects. The success stories in these sectors have gathered the attention of clients in the industrial sector, where cost and schedule overruns have become the norm. The central objective of this thesis is to help clients make the transition to this new type of project delivery.

This thesis was written in a three-paper format, where each paper addresses a challenge with the adoption of collaborative delivery methods. The first paper investigates what type of industrial …

Quality Control In Concrete Pavement: Early Detection Of Near-Surface Honeycombing With Gpr, Theresa Mccabe

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

This thesis presents utilization of Ground Penetrating Radar (GPR) for the assessment of highway pavements to gain a better understanding of this NDE method’s capabilities in terms of early detection of consolidation-caused air voids in brittle materials. The objectives are to first, determine the earliest time during the dormant, setting, and early hardening periods of concrete’s set that GPR can be used to detect shallow air voids. Secondly, the change in dielectric constant will be tracked over the first 24 hours of concrete setting in order to quantify the impact of the dielectric constant assumptions in early detection. Two different …

Evaluation Of The Dynamic Behavior Of Steel Staircases With Concrete Filled Pan Treads, Tyler Sondag

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

Vibration serviceability of staircases has been a growing challenge for structural engineers due to changing materials and structural forms. In order to prevent or correct serviceability problems due to structural vibrations, structural engineers should be able to predict the dynamic performance of a staircase structure. However, there are few technical guides available for designing steel staircases, and the ones that do exist are often limited in their applications. Currently, there is a lack of research on staircases that are less prone to vibrations, such as staircases with concrete filled pans that are composed of face and wall stringers. Therefore, the …

The Impact Of Pev User Charging Behavior In Building Public Charging Infrastructure, Ahmad Almaghrebi

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

Plug-in electric vehicles (PEVs) play a significant role in the development of green cities since they generate less pollution than conventional vehicles. To promote PEV adoption and mitigate range anxiety, charging infrastructure should be deployed at strategic locations that are readily accessible to the public. Nebraska is working on the expansion of charging infrastructure around the state; however, stakeholders face several difficulties in trying to minimize irregular charging behaviors. Most electric vehicle users plug in and leave their vehicles for an extended time at public parking lots designated for PEVs. Some users even leave their vehicles for longer than 24 …

How Acoustics In California High Performance Schools Relate To Student Achievement, Devin K. Wong

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

This research project seeks to determine if students attending K-12 schools meeting a minimum standard of high performance classroom conditions in the state of California do evidence higher scholastic achievement, based on publically available results on state-wide standardized tests. In three phases, a subset of 200+ schools applying for grants dedicated to building high performance schools over the past decade was correlated with an existing database of achievement scores for all public schools in California. The criteria utilized to specify high performance classrooms was provided by the California High Performance Initiative (HPI) Grant program. Academic achievement was evaluated on a …

The Experiment And Analysis Of Active Mechanisms For Enhancing Heat And Mass Transfer In Sorption Fluids, Ziqi Shen

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

This project was funded by American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE RP-1462). It is a three years’ research, including the literature review, labs construction, experiments and data analysis.

In this thesis, first of all, we conducted literature review of mechanism motion influence on heat and mass transfer and additive effect in absorption chiller. This part helps us understand the basic idea of how mechanism motion affects the heat and mass transfer of sorption fluids and gives us reference on how to select the experiment instrument and the experiment operation range.

In the second part, the instrument selection …

Subjective Perception Of Varying Reflection Densities In Room Impulse Responses, Hyun Hong

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

Reverberation time (RT) is a metric commonly used to describe room acoustic conditions, but different rooms which have the same reverberation time can have different reflection densities. Much less is known about how humans perceive different reflection densities and how sensitive humans are to changes in reflection density. Previous investigations in the existing literature have studied the upper limit of distinguishable reflection density using artificial impulse responses, but not with more realistic impulse responses simulated in room acoustic software or measured from real rooms. The aim of this dissertation is to investigate methods for quantifying reflection density from measured impulse …

Pump Controller Design For Variable Primary Flow Configuration Systems, Yifan Shi

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

Pump systems are utilized widely in Heating, Ventilation and Air-Conditioning (HVAC) systems. There are mainly three configuration types: (1) the constant primary-only flow configuration, (2) the constant primary/variable secondary flow configuration, and (3) the variable primary-only flow configuration. This thesis focuses on finding the optimal control strategy for it and programming a controller for easy in-field usage.

In this thesis, the pump brake horse power (BHP) of the three pump configurations is simulated and compared using varying control methods. The best pump efficiency staging and DP reset control methods are implemented into the pump controller. A one month field experiment …