Architectural Engineering Commons^™

Effect Of Rheology Modification On Fiber Orientation And Dispersion In 3d-Printed Ultra-High-Performance Concrete, Haodao Li, Alfred Addai-Nimoh, Seongho Han, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The extrusion process in 3D concrete printing (3DCP) facilitates horizontal alignment of steel fibers along the printing direction, thus enhancing the load-bearing capacity of printed elements. However, such shear-induced fiber alignment is highly sensitive to rheological properties. This study investigates how variations in dynamic yield stress (τd) and plastic viscosity (μ), influence the extrudability, fiber orientation and dispersion, and anisotropic mechanical behavior of ultra-high-performance concrete (UHPC). Five viscosity-modifying agent (VMA) types were incorporated at two content levels to modify the rheology of printable UHPC. Results showed that moderate VMA additions improved printability, whereas excessive contents markedly increased τd and μ; …

Transforming Dredged Sediment Into Reactive Clay: Critical Review Of Calcination, Reactivity, And Sustainable Valorization As Supplementary Cementitious Material, Seongho Han, Sanghwon Wi, Koochul Ji, Keun Hyeok Yang, Farshad Rajabipour, Kamal H. Khayat, Jinyoung Yoon

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Dredged sediment (DS) is generated worldwide in large volumes through routine port and waterway maintenance, yet its disposal presents environmental and economic challenges. Recently, calcined dredged sediment (CDS) has emerged as a supplementary cementitious material (SCM), offering a viable alternative to traditional SCMs, such as fly ash and slag cement. This review synthesizes current knowledge on the physical, chemical, and mineralogical characteristics of raw DS and pretreatment strategies aimed at dewatering, organic matter removal, and contaminant stabilization. The effects of calcination on the production of reactive amorphous aluminosilicates are also discussed. Emphasis is placed on physicochemical changes revealed by experimental …

Bond Behavior Of Full-Scale Beams Using Sustainable Self-Compacting Concrete, Hayder H. Alghazali, Atheer H.M. Algburi, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Sustainable concrete is a step towards greener and more eco-friendly concrete construction practices, helping to solve global environmental problems. The present study focuses on the bond behavior between steel reinforcement and greener self-compacting concrete, specifically sustainable self-compacting concrete (SUS-SCC). Three SUS-SCC mixtures with different fly ash (FA) to cement replacement levels of [50, 60, and 70% (by mass)] were developed. Twelve full-scale SUS-SCC beams with a cross-section of (305 x 57) mm and a total length of 3048 mm were cast and tested using a four-point load test setup. The effect of longitudinal and lateral steel reinforcement ratios in the …

Co2-Induced Changes In Rheology, Structural Evolution, And Particle Characteristics Of Cement Paste, Seongho Han, Tae Yong Shin, Seung Mo Kim, Jae Hong Kim, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The injection of carbon dioxide (CO₂) into cementitious systems has emerged as a promising approach to enhancing sustainability in concrete production. This study explores the impact of CO₂ injection on the rheological behavior, structural build-up, and particle size evolution of cement paste by systematically varying the water-to-cement ratio (w/c) (0.35, 0.4, and 0.5) and CO₂ concentration (0.06, 0.28, and 0.84 mol). Rheological analysis revealed a significant increase in initial yield stress with CO₂ injection. Using the Modified Bingham model, yield stress increased by 72 % and 150 % for 0.28- and 0.84-mol CO₂, …

A Green Concrete Mixture Using Rice Husk As Partially Cement Replacement, Khloud Khalid Eldamshiry, Zeina Salama, Amany Micheal, Rania Rushdy Moussa, Ayatallah Raafat

Architectural Engineering

Egypt's agricultural waste production has increased significantly in recent decades, leading to improper disposal methods and environmental pollution. Rice husks are the most common agricultural solid waste in Egypt, contributing to "black clouds" and causing health issues. On the other hand, Cement, a crucial component of construction materials, generates unsound residues and greenhouse gas emissions. Green concrete with rice husks could be a profitable solution for environmentally sound construction, reducing cement consumption and increasing the durability and integrity of new materials. This study investigates the use untreated rice husk fibres with a concrete mixture, avoiding burning and contributing to environmental …

Building Ecologies: Maintaining Land, Working With Wood, Taylor Jais

Masters Theses

This thesis critiques contemporary architecture and building practices for their fundamentally unsustainable and place-less assemblies that rely on extracting finite resources that generate significant emissions while simultaneously neglecting to consider the needs and existence of humans and non-human species with in the built environment. Through experimental material research that diverts “wood” waste streams and integrates land and multispecies care, this work demonstrates how maintenance-based approaches to construction can transform built assemblies into ecological systems. By deconstructing wood to its cellular components and recombining these elements in novel ways, this research reveals possibilities for collaborative, materials-driven, place-based building practices. This thesis …

Anti-Corrosion Performance Of Magnesium Potassium Phosphate Cement Coating On Steel Reinforcement: The Effect Of Boric Acid, Fan Zhang, Jihui Qin, Kangyi Cai, John J. Myers, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

It has recently been found that magnesium potassium phosphate cement (MKPC) paste coating applied on the surface of steel reinforcement can effectively retard the onset of corrosion and suppress corrosion reactions. However, the fast-setting nature of MKPC—which is a merit in repair—can be problematic in a practical engineering process of coating the steel reinforcement with MKPC paste. To address this problem, boric acid (H₃BO₃) was added as a retarder in an MKPC formulation to prolong the setting time. This work investigated the impact of boric acid (at 5% by weight of MgO) on the anti-corrosion performance …

Polypropylene As Partial Fine Aggregate Substitute In Concrete, Samuel E. Royston, Chrisitan G. Achkar, Nicholas B. Tabarez

Architectural Engineering

The objective of this project is to discover a structurally effective method in repurposing recyclable plastic waste through its partial substitution for traditional fine aggregate in concrete.

Results obtained from analysis indicate a 25 percent compressive strength reduction with polypropylene at a 10 percent partial substitution for total sand content. This material successfully performed as an alternative, presenting a ductile mode of failure.

Three material alternatives - polypropylene, polyethylene, and rubber - were substituted for a percentage of sand. These materials underwent concrete cylinder crushing tests to determine their ultimate crushing strength, with the intent of identifying the most effective …

A Concept Of Producing Aluminum In-Situ On The Moon Through Molten Salt Electrolysis, Jacob N. Ortega, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daniel Stutts, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

This paper presents a concept of producing aluminum in-situ on the lunar surface, namely, the Lunar In-Situ Aluminum Production through Molten Salt Electrolysis (LISAP-MSE) method developed at Missouri University of Science and Technology. This paper aims to demonstrate the use of electro-deoxidation to reduce aluminum oxide (i.e., alumina) into aluminum and oxygen gas via electrolysis in a molten salt bath for the production of aluminum on the Moon. It is shown that with a steady supply of hydrogen chloride, this in-situ resource utilization (ISRU) method could supply several necessary materials consumed in the electro-deoxidation process except hydrogen chloride to produce …

Beneficiation Of Lunar Regolith Simulants Through Electrostatic Sieving And Magnetic Separation, Peter Bachle, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

In the light of future development of lunar structures, in-situ feldspar beneficiation is imperative for metal extraction. This research incorporates the tandem use of electrostatic sieving and magnetic separation for collecting a specific size range and mineral composition from lunar soil that optimizes subsequent chemical processing. While earlier works focused on silt-sized particles, this work expands that range up to medium-grained sand with a greater variety of potential lunar regolith compositions. This work shows that a 2.5 kV, 7 Hz to 30Hz frequency, single-phase square wave can lift silt and fine sand for collection. This lifting is successful directly from …

Kinetic Modeling Of Electrostatic Sieving For Lunar Regolith Beneficiation: Case Studies, Easton Ingram, Emmanuela Amen Eze, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

A new kinetic particle modeling framework was developed to investigate electrostatic transport of lunar regolith particles with applications to the concept of electrostatic sieving. The new approach is based on kinetic particle dynamics and includes major modules of sampling the particle size distribution, solving electric fields, and tracking motion of charged dust grains. Case studies for a concept of electrostatic sieving were chosen to validate the new model. The simulation achieved similar yields reported in previous works, which served as validation of the model. The new model is computationally efficient and could serve as a design, analysis, and optimization tool.

Mechanism Underlying Effect Of Expansive Agent And Shrinkage Reducing Admixture On Mechanical Properties And Fiber-Matrix Bonding Of Fiber-Reinforced Mortar, Kamran Aghaee, Taihao Han, Aditya Kumar, Kamal Khayat

Materials Science and Engineering Faculty Research & Creative Works

Expansive agent (EA) and shrinkage reducing admixture (SRA) are utilized to reduce shrinkage and risk of cracking in concrete. EA compensates shrinkage by initial expansion, and SRA reduces surface tension in the pore fluid. Although EA and SRA effectively reduce shrinkage, they can impair micro-structure of concrete at high contents. The shrinkage reduction effect of EA and SRA is well known; however, there is limited knowledge about their negative effect on microstructure and fiber matrix interfacial transition zone (ITZ). The current study explores the effect of using 10 % CaO-based EA, 2 % SRA, and their combination on mechanical, shrinkage, …

A Spike-Shaped Anchorage For Steel Reinforced Polymer (Srp)-Strengthened Concrete Structures, Xingxing Zou, Keenan L. Mcburney, Lesley H. Sneed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Steel reinforced polymer (SRP) composite has recently emerged as an effective and economical solution for strengthening of reinforced concrete (RC) structures. Premature debonding failure of unanchored SRP at low load levels generally governs the performance of RC structures strengthened with externally bonded SRP. Therefore, a novel yet simple spike-shaped anchorage system was proposed in this study to prevent the debonding failure of SRP and to improve the interfacial shear capacity. Experimental investigation through single-lap shear tests of SRP-concrete joints showed that the anchorage system changed the failure mode from composite debonding to fiber rupture. In addition, the anchorage system substantially …

Toward Low Carbon Footprint And Lightweight Masonry Alkali-Activated Material, Zina Ebrahim, Mohammad Mastali, Marc Maguire

Durham School of Architectural Engineering and Construction: Faculty Publications

The portland cement concrete industry and the masonry industry are undergoing changes in response to skilled labor shortages and concerns over climate and pollution. There may be interest from parts of the industry in lower carbon footprint and lightweight masonry products. Toward this aim, the use of hemp shiv--the woody core of the hemp plant--in alkali-activated concrete was investigated herein and shown to have a wide range of impacts on the hardened state characteristics of a material suitable for structural concrete masonry units (CMUs) in accordance with ASTM C90 requirements. Hemp shiv is well known for its use in hempcrete, …

Lunar In-Situ Aluminum Production Through Molten Salt Electrolysis (Lisap-Mse), Jacob Ortega, Jeffrey D. Smith, Fateme Rezaei, David Bayless, William P. Schonberg, Daniel S. Stutts, Daoru Frank Han

NASA-Missouri Space Grant Consortium

The goal of Artemis is to establish a sustained presence on the Moon. To achieve so, numerous resources are necessary. The Moon contains several essential elements needed to sustain human presence. Most of those elements are trapped in the form of minerals. To refine those minerals into useful materials, reduction methods are needed. Most reduction methods on Earth require large amounts of mass and power which is unrealistic for early stages of building a lunar base. To solve this problem, we are developing a concept of Lunar In-Situ Aluminum Production through Molten Salt Electrolysis (LISAP-MSE).

The LISAP-MSE project, if successful, …

Precious Plastics - Plastic Brick Machine Fabrication, Timothy Ukaobasi Kanu, Evi Paraskevi Troulis

Architectural Engineering

The goal of this research is to determine the structural parameters of the recycled plastic polypropylene when molded into bricks resembling CMU blocks. To accomplish this, three mechanisms had to be assembled: the shredder, the injector, and the 1x1 mold. A tensile and compression test were to be performed on the plastic brick, and the values would be used to compare the tensile and compressive strength of PP plastic bricks, as well as their modulus of elasticity and stress vs. Strain performance. These values would be analyzed to determine whether it would be feasible to build an entire plastic wall. …

Effect Of Class C And Class F Fly Ash On Early-Age And Mature-Age Properties Of Calcium Sulfoaluminate Cement Paste, Sukanta K. Mondal, Carrie Clinton, Hongyan Ma, Aditya Kumar, Monday Uchenna Okoronkwo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To Promote the Sustainable Development of Eco-Efficient Calcium Sulfoaluminate (CSA) Cements through the Partial Replacement of the CSA Clinker with Supplementary Cementitious Waste Products, the Effects of Coal Fly Ashes on the Early-Age and Mature-Age Properties of a Calcium Sulfoaluminate (CSA)-Based Cement Paste Were Investigated. the Impacts of Both Class C and Class F Fly Ashes on the Rheological Properties, Hydration Kinetics, and Compressive Strength Development of CSA Cement Paste Were Studied. Rheology-Based Workability Parameters, Representing the Rate of Loss of Flowability, the Rate of Hardening, and the Placement Limit, Were Characterized for the Pastes Prepared with Fixed Water-To-Cement (W/c) …

Higher-Order Effects In Biaxial Flexure Of Gfrp I-Section Beams, Zia Razzaq, Faridoon Z. Razzaq

Civil & Environmental Engineering Faculty Publications

A theoretical study of Glass Fiber Reinforced Polymer (GFRP) beams subjected to biaxial bending moments is presented with a focus on the influence of higher-order effects on maximum normal stresses. It is shown that the biaxial bending type of loading causes a dramatic increase in the maximum normal stress for a GFRP beam when induced torsional effects are included. The study demonstrates that the traditional first-order theory can grossly underestimate the maximum normal stress in a GFRP beam. Based on the numerical results presented using a higher-order theory which also accounts for induced warping normal stresses, the maximum normal stress …

Cold-Formed Steel Strength Predictions For Combined Bending And Torsion, Yu Xia, Robert S. Glauz, Benjamin W. Schafer, Michael Seek, Hannah B. Blum

Engineering Technology Faculty Publications

Locally slender cross-section members, such as cold-formed steel Cee and Zee sections, are susceptible to significant twisting and high warping torsion stresses. Torsion considerations are complicated by whether it is derived as a first-order effect from loading or a second-order effect from instability. The current design for combined bending and torsion interaction has some limitations, including only considering the first yield in torsion and ignoring the cross-section slenderness in torsion. Previous work has derived a simple uniform equation to predict the bimoment capacity and two bimoment strength curves for local and distortional buckling under torsion only. This work is extended …

Quantifying The Workability Of Calcium Sulfoaluminate Cement Paste Using Time-Dependent Rheology, Sukanta K. Mondal, Adam Welz, Carrie Clinton, Kamal Khayat, Aditya Kumar, Monday Uchenna Okoronkwo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Poor workability is a common feature of calcium sulfoaluminate (CSA) cement paste. Multiple chemical admixtures, such as set retarders and dispersants, are frequently employed to improve the workability and delay the setting of CSA cement paste. A quantitative assessment of the compatibility, efficiency, and the effects of the admixtures on cement paste workability is critical for the design of an appropriate paste formulation and admixture proportioning. Very limited studies are available on the quantitative rheology-based method for evaluating the workability of calcium sulfoaluminate cement pastes. This study presents a novel and robust time-dependent rheological method for quantifying the workability of …

Assessment Of Carbon Dioxide Emission And Its Impact On High-Rise Mixed-Use Buildings In Egypt, Ahmed Salah Hamza

Theses and Dissertations

With Egypt's vision of 2030 focusing on sustainable development with a true emphasis on Carbon Dioxide (CO₂) emission reduction in the newly built cities and high-rise buildings, efforts are exerted on various levels towards accomplishing the vision’s goals. This is achieved through multiple tools and models associated with aiding the reduction of carbon emissions, yet not a clear one was introduced for the mixed-use buildings in Egypt.

Through this work, a significant gap was identified with respect to high-rise buildings carbon emission assessment in Egypt. This was a main driving force for this work in an attempt to …

Analysis Of Burning Wood In The Transient State And The Application To Structural Design, Roberta Veliz, Kimberly Guzman

Architectural Engineering

Determining the extent of the contribution of exposed timber on compartment fire dynamics in open floor plans is a complex process. Designers traditionally used compartmentalization design methods which create spaces where flashover is likely, given the fuel load and ventilation conditions. However, due to the large geometric dimensions and spread of fuel, fires in open floor plans are more likely to remain as localized or traveling fires. As such, an understanding of not only ignition potential but also flame spread is critical to characterizing the contribution of exposed timber. An integral step in characterizing the potential contribution is through an …

Bridge Build, Andrew Little

Student Scholarship

Bridge build design that includes not only a building process, but a research paper to make the best build possible as well.

Speculations On A City For Mars, Edouard Terzis

School of Architecture - Theses

This thesis proposes the reinterpretation of architectural forms as the index of the constitution of the idea of the city. “Speculations on a City on Mars” is paradoxical in a sense as it superposes both the managerial representation of a city, that is Zoning, along with the speculative aspect of an extra-terrestrial city.

Wall Panel Optimization For Refugee Shelters In Germany: An Ahp Study, Zhu Jiadong

Masters Theses & Specialist Projects

The German government is experiencing difficulties housing and assimilating Syrian refugees in its borders. Erecting temporary shelters on location is one way to deal with the current crises. This thesis attempts to use Analytic Hierarchy Process (AHP) to determine the optimum combination of materials and construction methods to be used in the shelter’s walls in order to improve the living conditions of the refugees and to ensure that the cost is acceptable to the German government. This thesis compares six existing wall panel products from China, which have the lowest cost on the worldwide market. The R-value, strength, price, weight, …

Lateral Strength And Ductile Behavior Of A Mortise-Tenon Connected Timber Frame, Alexandros Kouromenos

Master's Theses

The primary goals of this project were to examine the amount of lateral force resisted by a single-bay mortise-tenon connected timber moment frame, and to introduce ductile behavior into the mortise-tenon connections by adding a steel sleeve around a traditional wood peg. This research aimed to provide proof that traditional timber frames are capable of ductile racking while reliably complying with ASCE 7-10 building code drift speci! cations, implying an increase in the ASCE 7-10 ductility factor (R) for wood frames when used as lateral force resisting elements. A secondary goal was to promote traditional heavy timber framing as a …

Acoustic Management Of Library Fishbowls, Zachary J. Lilley

Materials Engineering

The purpose of this project is to aid the Cal Poly Robert E. Kennedy library in modifying the “fishbowl” study spaces to more effectively maintain the desirable sound that is generated within the fishbowls while avoiding the entrance and exit of excess noise to and from the fishbowls. A collaboration between the Materials Engineering Department and the Architecture Department provided the combined expertise needed to design, test, and install a prototype acoustic treatment in fishbowl 216-R in consultation with the Cal Poly Library as the voice of the customer. The fishbowl’s undesirable acoustic properties can be attributed to the hard …

Effect Of The Inherent Eccentricity In Single-Lap Direct-Shear Tests Of Pbo Frcm-Concrete Joints, Tommaso D'Antino, Lesley Sneed, Christian Carloni, Carlo Pellegrino

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Investigation of the bond between fiber reinforced composites and the substrates onto which they are applied is of critical importance to understand their failure mechanisms. The bond behavior can be studied using different experimental test set-ups; the most commonly used are the single-lap and double-lap direct-shear tests. Although single-lap shear tests are simpler to carry out than double-lap shear tests, the presence of an eccentricity between the pulling and restraining forces leads to a mixed mode fracture process at the interface, which may influence the results. This study investigates the eccentricity effect on the bond behavior of fiber reinforced cementitious …

Post-Repair Seismic Assessment Of Rc Bridges Damaged With Fractured Column Bars - A Numerical Approach, Ruili He, Yang Yang, Lesley H. Sneed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Seismic repair of reinforced concrete (RC) bridge columns has been studied extensively during the past several decades; however, few studies have been conducted on the influence of the column repair (member level) on the post-repair performance of bridge structures (system level). In a previous experimental study by the authors, a method was developed to rapidly repair severely damaged RC bridge columns to enable the quick reopening of the bridge to emergency traffic. Thus, a lower limit state was used for the repair design, so that the lateral strength and drift capacity of a repaired RC column with fractured longitudinal bars …

Influence Of The Substrate Characteristics On The Bond Behavior Of Pbo Frcm-Concrete Joints, Tommaso D'Antino, Lesley H. Sneed, Christian Carloni, Carlo Pellegrino

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fiber Reinforced Cementitious Matrix (FRCM) composites can be employed as a valid alternative to Fiber Reinforced Polymers (FRP) composites for strengthening existing reinforced concrete (RC) structures. The weakness of FRCM-concrete joints has been reported to be at the matrix-fiber interface rather than within the concrete substrate, as is usually reported in the case of FRP-concrete joints. The experimental investigations regarding FRCM strengthening available in the literature have been performed by applying the FRCM composite onto a surface that was treated before the application, usually by grinding or sandblasting. However, the role of the substrate characteristics on the failure mechanism of …