Architectural Engineering Commons^™

An Experimental Study On Bond Strength Of Reinforcing Steel In High-Volume Fly-Ash Concrete, Trevor J. Looney, Mahdi Arezoumandi, Jeffery S. Volz, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The production of Portland cement-the key ingredient in concrete-generates a significant amount of carbon dioxide. However, because of its incredible versatility, availability, and relatively low cost, concrete is the most consumed manmade material on the planet. One method of reducing concrete's contribution to greenhouse gas emissions is the use of fly ash to replace a significant amount of the cement. an experimental investigation was conducted to compare the bond strength of reinforcing steel in high-volume fly-ash concrete (HVFAC)-concrete with at least 50 % of the cement replaced with fly ash-with conventional concrete (CC). This study investigated two HVFAC mixes [with …

Influencing Factors On The Dynamic Properties Of Organobentonites, Bate Bate, Susan Burns

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The dynamic responses of soils are important engineering properties, especially for soils with high organic contents, because these soils can underlie critical support structures such as highway bridges or levees. Consequently, the initial tangent shear modulus (Gmax), secant shear modulus ratio (G/Gmax), and damping ratio (D) are important parameters in evaluating the dynamic soil behavior for soils subjected to earthquake, wind, waves, traffic, and equipment vibration. in this study, these dynamic properties of organ bentonites were quantified experimentally using resonant column tests. the results from this study were evaluated in terms of the effect of shear strain, organic content, and …

Effect Of Scc Mixture Composition On Thixotropy And Formwork Pressure, A. F. Omran, Kamal H. Khayat, Y. M. Elaguab

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High lateral pressure exerted on formwork systems by self-consolidating concrete (SCC) is one of the hindrances for using such highly flowable concrete in cast-in-place applications. Self-consolidating concrete is a complex system that can be made using a wide range of mixture proportioning and often incorporated various chemical admixtures and supplementary cementitious materials. the investigation of the effect of each material ingredient independently on lateral pressure of SCC is not a simple task. in this study, thixotropy is rather used to assess the effect of various mixture parameters on formwork pressure. Thixotropy is determined by the evaluation of the structural buildup …

Statistical Modelling Of The Coupled Effect Of Mix Design And Rebar Spacing On Restricted Flow Characteristics Of Scc, Yahia Ammar, Khayat H. Kamal, Sayed Mohammed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Self-consolidating concrete (SCC) is designed to exhibit high deformability and stability to maintain homogenous suspension of coarse aggregate particles in the mortar during flow to ensure adequate passing ability of the concrete through restricted areas and the filling of the formwork without any consolidation. Proper deformability and uniform suspension of coarse aggregate particles in the matrix are key parameters to ensure successful casting and adequate in situ performance. the required flow properties of concrete are affected by the rheological properties of the mixture and the characteristics of the cast element, including the level of reinforcement. the mixture proportioning of SCC …

Numerical Simulation Of Particle-Driven Gravity Currents, Sangdo An, Pierre Y. Julien, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Particle-driven gravity currents frequently occur in nature, for instance as turbidity currents in reservoirs. They are produced by the buoyant forces between fluids of different density and can introduce sediments and pollutants into water bodies. In this study, the propagation dynamics of gravity currents is investigated using the FLOW-3D computational fluid dynamics code. The performance of the numerical model using two different turbulence closure schemes namely the renormalization group (RNG) k-ε scheme in a Reynold-averaged Navier-Stokes framework (RANS) and the large-eddy simulation (LES) technique using the Smagorinsky scheme, were compared with laboratory experiments. The numerical simulations focus on two different …

Quantifying The Effect Of Nanoparticles On As(V) Ecotoxicity Exemplified By Nano-Fe2o3 (Magnetic) And Nano-Al2o3, Ji Hu, Demin Wang, Brett E. Forthaus, Jianmin Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Nano-Fe₂O₃ (magnetic) and nano-Al₂O₃ are increasingly used in biomedical fields for cellular labeling and drug delivery, and in the industry as catalysts. However, they may also serve as carriers of toxic contaminants and negatively impact the environment and human health. in the present study, Ceriodaphnia dubia was used to assess the toxicity of these nanoparticles (NPs) with and without the presence of background arsenic(V) (As[V]). the results showed that although these NPs alone did not exhibit significant toxicity in the experimental concentration range, they could significantly enhance the toxicity of As(V). the accumulation of …

Can We Teach Lean Construction Methods In Schools Of Architecture, Gary Graham

Fall 2012 Faculty Showcase

Traditionally, schools of architecture are not great laboratories to explore the collaborative processes and teamwork that are essential to integrated design and delivery practices as exemplified by Lean Construction. The pre-eminence of the “hero-architect” in the design studio is in direct conflict with methods that can reduce risk and improve the efficiency of the design and construction delivery process. Risk? Efficiency? Delivery Process?... not mention Cost Control, Schedule and Constructability, are foreign concepts to the predominant design studio culture.

Integrated practices and integrated project delivery are clearly “hot” topics in the design and construction industry today. They are a response …

Lifecycle Energy Consumption Prediction Of Residential Buildings By Incorporating Longitudinal Uncertainties, Endong Wang, Zhigang Shen

Durham School of Architectural Engineering and Construction: Faculty Publications

Accurate prediction of buildings’ lifecycle energy consumption is a critical part in lifecycle assessment of residential buildings. Longitudinal variations in building conditions, weather conditions and building’s service life can cause significant deviation of the prediction from the real lifecycle energy consumption. The objective is to improve the accuracy of lifecycle energy consumption prediction by properly modelling the longitudinal variations in residential energy consumption model using Markov chain based stochastic approach. A stochastic Markov model considering longitudinal uncertainties in building condition, degree days, and service life is developed: 1) Building’s service life is estimated through Markov deterioration curve derived from actual …

Survey Of Surface Fault Rupture And Structure Interation, Lucy Redmond

Master's Theses

This report aims to raise awareness of the hazards of surface fault rupture and to identify parameters that influence structural performance during earthquake fault rupture. In researching structures subject to surface rupture, both damaged and sound, guidelines and procedures to evaluate buildings in potential hazard areas are developed herein. Little to no guidance on how to design for surface fault offset exists in current codes and design guides. Thus it is important create tools for designers to appropriately analyze structures by developing guidance and requirements to aid designers in their strength assessment of a structure subject to this particular hazard. …

The Bridge Newsletter Winter 2012, Missouri University Of Science And Technology

The Bridge Newsletter

-Creating bridge beams that will last 100 years
-Great school, great price
-Recruiting technical minds
-Combatting obesity, diabetes

Computational Modeling Of Baffled Disinfection Tanks, Zachary H. Taylor, Qing Xu, Jordan M. Wilson, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The present study focuses on understanding the flow dynamics of baffled disinfection contact tanks through the use of computational fluid dynamics (CFD). In particular, we seek to address the key question: for a given footprint of a contact tank with a fixed inlet configuration, how does the hydraulic efficiency of the tank depend on the configuration of internal baffles? The benchmark contact tank geometry in our study is shown in Figure 1. In order to define guidelines for hydraulically efficient baffle tanks, we perform a total of 36 high-resolution three-dimensional simulations to quantify the efficiency of a laboratory scale tank …

Roof Drainage: Not My Problem ... Maybe, John Lawson

Architectural Engineering

Many structural engineers are surprised to learn that the International Building Code (IBC, 2009) requires the roof structure to be engineered for standing water weight in the vicinity of the drains and scuppers regardless of roof slope. In addition, some low-slope roofs also require special attention for water weight and stiffness for safety against ponding failures or protection against accelerated roofing deterioration. With a mixture of overlapping design disciplines between the architect, plumbing consultant and structural engineer, proper roof drainage is often not fully addressed in building design and can lead to catastrophic collapse.

The author has been involved as …

Investigating Self-Cooling Effects Of Ventilated Attics Under Different Roof And Ambient Temperatures In Summer, Zhigang Shen, Shimin Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

An unsteady computational fluid dynamics model is employed to simulate summer-time buoyancy-driven turbulent ventilation in gable-roof attics of residential buildings. The energy performance of vented attics is assessed by comparing their performance to sealed attics with the same geometry and insulation configurations. The simulated boundary conditions of the roof-top temperature ranging between 295.15 K and 345.15 K, coupled with an ambient temperature ranging between 295.15 K and 315.15 K, resemble the summer attic conditions with effects of solar irradiance on the roofs. Simulation results indicate that both the vented and sealed attics are dominated by thermal stratification. The cooling load …

Cal Viva: Assessing The Seismic Vulnerablility Of California's State-Owned Buildings, James Guthrie, Jill Nelson

Architectural Engineering

In the last 20 years, agencies and departments in the State of California have initiated seismic vulnerability programs for state-owned buildings with goals ranging from life safety to reduced post-earthquake disruption. Until now, there has not been an assessment of all state-owned buildings with the goal of identifying and assessing the seismic vulnerability of those buildings needed for response and recovery efforts after an earthquake.

The California Vital Infrastructure Vulnerability Assessment Project (Cal VIVA), sponsored by the California Emergency Management Agency (Cal EMA) and funded through FEMA, has developed a statewide approach to assessing the vulnerability of the state-owned building …

Dendrochemistry Of Multiple Releases Of Chlorinated Solvents At A Former Industrial Site, Jean Christophe Balouet, Joel Gerard Burken, Frank Karg, Don Vroblesky, Kevin T. Smith, Håkan Grudd, Anders Rindby, François Beaujard, Michel Chalot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Trees Can Take Up and Assimilate Contaminants from the Soil, Subsurface, and Groundwater. Contaminants in the Transpiration Stream Can Become Bound or Incorporated into the Annual Rings Formed in Trees of the Temperate Zones. the Chemical Analysis of Precisely Dated Tree Rings, Called Dendrochemistry, Can Be Used to Interpret Past Plant Interactions with Contaminants. This Investigation Demonstrates that Dendrochemistry Can Be Used to Generate Historical Scenarios of Past Contamination of Groundwater by Chlorinated Solvents at a Site in Verl, Germany. Increment Cores from Trees at the Verl Site Were Collected and Analyzed by Energy-Dispersive X-Ray Fluorescence (EDXRF) Line Scanning. the …

Framework For Formative Assessment Learning Strategies In Built Environment Higher Education Programmes, Lloyd Scott, Christopher Fortune

Conference papers

Formative assessment has begun to be recognized as a driving force for enhancing student learning. This paper addresses the context of Built Environment (BE) undergraduate programmes and the findings from a research project in the context of the changing Higher Education (HE) environment. The analysis of the literature on formative assessment shows that there is a common concern among the educational researchers about the function and position of assessment in HE today. The overall aim of this research is to contribute to an improvement in the quality of student learning in BE undergraduate education through the development of a theoretical …

An Experimental Study On Bond Strength Of Reinforcing Steel In Self-Consolidating Concrete, Trevor J. Looney, Mahdi Arezoumandi, Jeffery S. Volz, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An experimental investigation was conducted to compare the bond strength of reinforcing steel in self-consolidating concrete (SCC) with conventional concrete (CC). This study investigated two different compressive strengths of SCC as well as CC. the experimental program consisted of 24 pull-out specimens as well as 12 full-scale beams (three for each concrete type and strength). the pull-out specimens were based on RILEM recommendations, and the beam specimens were tested under a simply supported four-point loading condition. the CC test results served as a control and were used to evaluate the results from the SCC pull-out and beam specimen tests. Furthermore, …

Behavior Of Segmental Precast Posttensioned Bridge Piers Under Lateral Loads, Haitham Dawood, Mohamed Elgawady, Joshua Hewes

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Abstract a segmental precast posttensioned (SPPT) bridge pier is an economic recentering structural system. Understanding the seismic behavior of a SPPT system is an important step toward its application in high seismic zones. This paper presents a detailed three-dimensional finite-element (FE) model that was developed using the ABAQUS platform. a brief description and discussion of cyclic tests on eight large-scale SPPT piers is also presented. Four of the piers were constructed and tested to a predefined degree of damage. Then, these piers were retrofitted and retested. the FE models developed and presented in this paper predicted the backbone curves of …

An Innovative Solution Set Of Algorithm For Converting Architectural Drawings To Vector-Based Computer Graphics, Yuye Peng

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

Appraisal Floor Plan Sketch (AFPS) as a simplified architectural floor plan shows the bird's eye view of a building’s spatial arrangement. An efficient automated vectorization system of AFPS not only fulfills AFPS’s preservation and dissemination purposes but also helps extract the building’s geometric information, which can be used to create 3D models of the building and improve building energy efficiency. The purpose of this study is to develop an automated system for converting scanned AFPS into vector based computer graphics.

Text/graphic separation and corner detection are two essential components in this vectorization system. Text/graphic separation ensures that only graphic data …

Instruction Manual: Photogrammetry As A Non-Contact Measurement System In Large Scale Structural Testing, Anahid A. Behrouzi, Rhu Li

Architectural Engineering

Photogrammetry is a non-contact measurement method that is being used in large scale structural experimentation to extract information about the overall geometry of the specimen as well as the XYZ motion of select points on the structure during testing. This is possible through the use of high-resolution still cameras that capture several photographs of the specimen and are processed using photogrammetric software. The following document will focus specifically on the application of PhotoModeler® as the image post-processing tool. This instruction manual aims to provide guidance to researchers who would like to adopt photogrammetric techniques to acquire experimental test data, especially …