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Articles 931 - 960 of 2201

Full-Text Articles in Civil and Environmental Engineering

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 Aug 2022

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 …


Crack Control And Bond Performance Of Alternative Coated Reinforcements In Concrete, Sachin Sreedhara Aug 2022

Crack Control And Bond Performance Of Alternative Coated Reinforcements In Concrete, Sachin Sreedhara

All Dissertations

Concrete cracking in structures is a ubiquitous problem which can lead to the deterioration of the structure. Other than affecting the strength aspect of a structure, cracking impacts the serviceability criteria as well. Although cracking phenomenon in any structure is highly inevitable, it has to be minimized in order to maintain a structure’s life effectively. Cracking in reinforced concrete structures is related to the bond strength developed between the bar and the concrete. It also depends on an ability of the bar to resist the stresses due to shrinkage to minimize the crack. Another important aspect is the resistance offered …


The Effects Of Curing Temperature On The Hydration Kinetics Of Plain And Fly Ash Pastes And Compressive Strength Of Corresponding Mortars With And Without Nano-Tio2 Addition., Dan Huang, Mirian Velay-Lizancos, Jan Olek Jul 2022

The Effects Of Curing Temperature On The Hydration Kinetics Of Plain And Fly Ash Pastes And Compressive Strength Of Corresponding Mortars With And Without Nano-Tio2 Addition., Dan Huang, Mirian Velay-Lizancos, Jan Olek

International Conference on Durability of Concrete Structures

Incorporation of fly ash in cementitious systems containing ordinary portland cement (OPC) increases their long-term strength and durability. However, replacement of cement by fly ash also reduces the heat of hydration of such systems and reduces early-age strength development. The reduced rate of strength development can increase the risk of durability problems, e.g. scaling, in cases when young concrete is exposed to low temperatures and deicing chemicals. This study investigated the potential of nano-titanium dioxide (nano-TiO2) particles to modify the hydration kinetics of fly ash pastes and compressive strength development of corresponding mortars cured under low (4°C) and …


Corrosion Performance Of Embedded Steel Bar In Cl--Contaminated Limestone Calcined Clay Cement (Lc3) At Initial Stage Of Hydration, Weiwen Li, Zuhua Xu, Yaocheng Wang, Xin Wang, Feng Xing Jul 2022

Corrosion Performance Of Embedded Steel Bar In Cl--Contaminated Limestone Calcined Clay Cement (Lc3) At Initial Stage Of Hydration, Weiwen Li, Zuhua Xu, Yaocheng Wang, Xin Wang, Feng Xing

International Conference on Durability of Concrete Structures

Limestone Calcined Clay Cement (LC3) presents brilliant properties in binding Cl- so that the embedded steel bars are probably protected in Cl--contaminated condition, which meets the need of sea sand application. However, the corrosion performance of steel bars embedded in LC3 paste with Cl‑ is unclear, especially in early age hydration. Thus, a series of experiments were carried out to evaluate the corrosion performance of steel bars on initial and hardened stages of hydration, including concentration of OH- and Cl- in real pore solution, open circuit potential (OCP) and chemical elements of steel bars. …


Investigation On The Properties Of Calcium Sulfoaluminate Cement Waterproof Repair Mortar Modified With Ethylene-Vinyl Acetate Powder, Dong Dong Jul 2022

Investigation On The Properties Of Calcium Sulfoaluminate Cement Waterproof Repair Mortar Modified With Ethylene-Vinyl Acetate Powder, Dong Dong

International Conference on Durability of Concrete Structures

本文采用乙烯-醋酸乙烯酯(EVA)粉体和CSA水泥制备了防水修复砂浆,并对其水化和性能进行了研究。结果表明,EVA粉体延长了凝固时间,提高了防水修补砂浆的流动性,使其在实际工程中更容易应用。EVA粉提高了防水修复砂浆的不渗透性,降低了吸水性。虽然EVA粉降低了防水修补砂浆的抗弯强度和抗压强度,但它仍然符合JC/T 2381-2016标准对刚性修复砂浆的要求。EVA粉体降低了防水修复砂浆的收缩率,改善了界面过渡区和拉伸粘接强度、弯曲粘接强度等粘接性能。EVA粉末抑制CSA水泥的水合作用6 h,在3 d水化年龄时抑制作用消失。


Mechanical And Durability Properties Of Geopolymer Concrete – A Review, Lelian Elkhatib, Fadi Al Aridi, Adel Elkordi, Jamal Khatib Jun 2022

Mechanical And Durability Properties Of Geopolymer Concrete – A Review, Lelian Elkhatib, Fadi Al Aridi, Adel Elkordi, Jamal Khatib

BAU Journal - Science and Technology

Owing to the ongoing increase in human population, there is a need for more construction projects including residential buildings and other amenities. Concrete is by far the dominant material used in construction and cement is a main ingredient. Cement manufacture is an energy intensive process and emit large amounts of carbon dioxide into the atmosphere. A reduction in the amount of cement used in construction is greatly beneficial. The use of geopolymer or alkali activated materials can serve this purpose as it attempts to totally replace cement in concrete. Geopolymers are materials that consist mainly of silica and alumina materials …


Production Of Low-Cost Self-Consolidating Concrete (Scc) Using Manufactured Aggregates, Rabab Raydan, Farah Chamseddine, Ali Jahami, Oussama Baalbaki, Jamal Khatib, Adel Elkordi Jun 2022

Production Of Low-Cost Self-Consolidating Concrete (Scc) Using Manufactured Aggregates, Rabab Raydan, Farah Chamseddine, Ali Jahami, Oussama Baalbaki, Jamal Khatib, Adel Elkordi

BAU Journal - Science and Technology

Limitations to the sources of aggregates and the unavailability of sand is becoming a problematic issue for concrete production. A novel technology of manufactured aggregates can produce well graded round aggregates that can substitute natural aggregates while maintaining the same characteristics needed and preserving the resources. Self-Consolidating Concrete (SCC) using manufactured aggregates is assessed in this experimental work to understand the variability of workability properties and mechanical properties with the changes in w/c ratio and percentages of Coarse Aggregates and Manufactured Sand to Natural Sand in order to choose the best mixture that satisfies an adequate overall performance. Targeting compressive …


Impedance Analysis Of Anodized Aluminum And Structural Bridge Tendons, Justin Silnutzer Jun 2022

Impedance Analysis Of Anodized Aluminum And Structural Bridge Tendons, Justin Silnutzer

USF Tampa Graduate Theses and Dissertations

This is a two-part thesis with the overall investigation technique being electrochemical impedance spectroscopy (EIS). In the first part, EIS is used to estimate the layer thickness of anodized aluminum oxide. This required the development of an appropriate electrical circuit model; that with parameters that correspond to physical properties of the oxide. In this work, it was found that for thicker oxides of which the outer porous layer is greater than 12 microns, impedance may be used to estimate the outer layer thickness. However, further research is required to understand the role of outer porous layer structure on the impedance …


Machine Learning Enabled Closed-Form Models To Predict Strength Of Alkali-Activated Systems, Taihao Han, Eslam Gomaa, Ahmed Gheni, Jie Huang, Mohamed Elgawady, Aditya Kumar Jun 2022

Machine Learning Enabled Closed-Form Models To Predict Strength Of Alkali-Activated Systems, Taihao Han, Eslam Gomaa, Ahmed Gheni, Jie Huang, Mohamed Elgawady, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Alkali-activated mortar (AAM) is an emerging eco-friendly construction material, which can complement ordinary Portland cement (OPC) mortars. Prediction of properties of AAMs—albeit much needed to complement experiments—is difficult, owing to substantive batch-to-batch variations in physicochemical properties of their precursors (i.e., aluminosilicate and activator solution). In this study, a machine learning (ML) model is employed; and it is shown that the model—once trained and optimized—can reliably predict compressive strength of AAMs solely from their initial physicochemical attributes. Prediction performance of the model improves when multiple compositional descriptors of the aluminosilicate are combined into a singular, composite chemostructural descriptor (i.e., network ratio …


Dynamic Response Of Elastic Two-Story Steel Moment Frame Scaled Structure Equipped With Viscous Dampers, Garrett L. Barker, Alexander L. Poirier Jun 2022

Dynamic Response Of Elastic Two-Story Steel Moment Frame Scaled Structure Equipped With Viscous Dampers, Garrett L. Barker, Alexander L. Poirier

Architectural Engineering

The authors of this report are Architectural Engineering undergraduate students at California Polytechnic State University, San Luis Obispo. Damping is a complex, experimentally derived value that is affected by many structural properties and has a profound effect on the dynamic response of structures. Deducing the inherent damping of a steel moment frame and affecting the damping ratio with viscous dampers are two topics explored in this paper. Dampers are commonly implemented in resilient structures that perform better in a design basis earthquake, reducing the seismic cost and downtime. Undergraduate coursework does not delve into the factors that affect damping and …


The Impact Of Material And Environmental Properties On The Ettringite - Metaettringite Thermochemical Reaction, Aaron Strand May 2022

The Impact Of Material And Environmental Properties On The Ettringite - Metaettringite Thermochemical Reaction, Aaron Strand

Dissertations

The use of energy is an essential need for people, with demand constantly increasing due to an increasing population and an increase in living and comfort standards. Since 1965, world energy consumption has quadrupled. During peak utilization, the strain on the grid infrastructure can be immense. As energy demand fluctuates during different times of the day and year, the energy production needs to scale accordingly This creates inefficiencies within the system such as over building generation capacity or losses from start up or ramping up production. This can be alleviated through load leveling where excess energy generated during low demand …


A Review Of Current Construction Guidelines To Inform The Design Of Rammed Earth Houses In Seismically Active Zones, David Thompson, Charles Augarde, Juan Pablo Osorio May 2022

A Review Of Current Construction Guidelines To Inform The Design Of Rammed Earth Houses In Seismically Active Zones, David Thompson, Charles Augarde, Juan Pablo Osorio

Articles

Sustainability in the materials we use for construction is a prime concern, focusing on reducing the embodied energy and carbon footprints of the materials used. The cement used in concrete products is responsible for a significant proportion of Man's CO2 emissions and its production requires substantial energy input, as do fired clay products. For this reason, products formed from unfired earthen materials are of increasing interest and the current challenges include devising means of robust design for strength and to address durability concerns. One form of earthen construction that employs an in-situ method is rammed earth, and it is a …


A Circular Economy Approach To Improve E-Waste Recycling In California: Economic Potential And Policy Options, Kripa Shah May 2022

A Circular Economy Approach To Improve E-Waste Recycling In California: Economic Potential And Policy Options, Kripa Shah

Master's Projects and Capstones

The higher consumption rates of electronic devices along with their short life cycles and few repair options poses a huge challenge for E-waste industries to manage them effectively. E-waste comprises of hazardous materials and toxic constituents that can affect the environment and public health through improper disposal. However, they also contain few valuable materials that, if recovered, can reduce the dependence on virgin raw materials. Circular economy has the potential to utilize these valuable materials and gain environment and socio-economic benefits. The research explains how the adoption of a circular economy approach can help improve the E-waste recycling in California …


The Living Breakwaters Pdr Efforts: Conceptual Scheduling, Calvin O. Walters Jr. May 2022

The Living Breakwaters Pdr Efforts: Conceptual Scheduling, Calvin O. Walters Jr.

Publications and Research

On October 29, 2012, Superstorm Sandy caused nearly $19 billion in damages in New York City including 69,000 residential units across the five boroughs. This disaster precipitated a post-disaster-rebuilding (PDR) project including roughly $4.2 billion in a Community Development Block Grant allocated towards PDR projects. A portion of the grant was used to construct a living breakwater in Tottenville, Staten Island, consisting of a resiliency approach to risk reduction through erosion prevention, wave energy attenuation, and enhancement of ecosystems and social resiliency to improve resistance to storms for the community of Tottenville. The ridges of each breakwater are designed with …


Hydration Of High-Alumina Calcium Aluminate Cements With Carbonate And Sulfate Additives, Jonathan Lapeyre, Sai Akshay Ponduru, Monday Uchenna Okoronkwo, Hongyan Ma, Aditya Kumar May 2022

Hydration Of High-Alumina Calcium Aluminate Cements With Carbonate And Sulfate Additives, Jonathan Lapeyre, Sai Akshay Ponduru, Monday Uchenna Okoronkwo, Hongyan Ma, Aditya Kumar

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study investigated the influence of limestone (LS) and calcium sulfate (C$) mineral additives on the hydration kinetics of high-α-Al2O3 calcium aluminate cement (CAC) utilizing experimental techniques and thermodynamic simulations. Increasing the replacement level of limestone or calcium sulfate increased the cumulative heat of the hydration reaction. The limestone exhibited limited acceleratory effects to the CAC hydration kinetics due to the coarseness of the powder. The coarse particle size distribution limited any heterogenous nucleation that would have occurred with a finer particle size as well as the intrinsic insolubility kinetically limits the formation of monocarboaluminate phases. Conversely, …


Evaluating The Effects Of Curing Methods On Bcsa Cement Concrete, Hannah Allen May 2022

Evaluating The Effects Of Curing Methods On Bcsa Cement Concrete, Hannah Allen

Civil Engineering Undergraduate Honors Theses

BCSA cement is a type of cement that makes concrete set up much quicker than typical portland cement concrete. BCSA cement concrete also has a much higher compressive strength than that of portland cement concrete. This study was conducted to determine the effect of different curing conditions on the compressive strength of BCSA cement concrete.


Mechanical Behavior Of Clay Soil Stabilized With Fly Ash And Bottom Ash, Soewignjo Agus Nugroho, Azra Zulnasari, Ferry Fatnanta, Andius Dasa Putra Apr 2022

Mechanical Behavior Of Clay Soil Stabilized With Fly Ash And Bottom Ash, Soewignjo Agus Nugroho, Azra Zulnasari, Ferry Fatnanta, Andius Dasa Putra

Makara Journal of Technology

Soil is one of the most important aspects of an infrastructure given its functions of receiving and holding structural loads. However, not all soils have good physical and mechanical properties. To overcome those conditions, stabilization of the soil is practiced to meet the technical requirements. This study aims to determine the behavior of high plasticity clay stabilized with lime, fly ash, and bottom ash. These additives can be used as a stabilizing agent to increase soil strength. The percentage of additives varied from 5%–25% then mixed with clay and were tested through the (Unconfined Compression Strength (UCS) test. The UCS …


Enhancement Of Biogas Production Through Solid-State Anaerobic Co-Digestion Of Food Waste And Corn Cobs, Lukhi Mulia Shitophyta, Anisa Salsabila, Firanita Angraini Putri, Siti Jamilatun Apr 2022

Enhancement Of Biogas Production Through Solid-State Anaerobic Co-Digestion Of Food Waste And Corn Cobs, Lukhi Mulia Shitophyta, Anisa Salsabila, Firanita Angraini Putri, Siti Jamilatun

Makara Journal of Technology

Although biogas has been primarily produced through liquid anaerobic digestion, this method leads to the floating and stratification of fibers and non-homogeneous mixing, which can reduce the biogas yield. Alternatively, biogas can be produced by the solid-state anaerobic digestion (SS-AD) of organic material with a high solid content, such as corn cobs. We investigated the co-digestion of food waste and corn cobs as a biomass feedstock for SS-AD in biogas production. We measured the effects of the total solid (TS) content, percentage of food waste, and reduction in volatile solids (VS), from which we determined its appropriate kinetic model. We …


Control Strategy For Solar Energy-Saving Lamps For Optimized Energy Utilization And Sustainability Of Operation Durability: Indonesia Case, Burhanuddin Halimi, Agus Purwadi, Nana Heryana Apr 2022

Control Strategy For Solar Energy-Saving Lamps For Optimized Energy Utilization And Sustainability Of Operation Durability: Indonesia Case, Burhanuddin Halimi, Agus Purwadi, Nana Heryana

Makara Journal of Technology

To solve the electrification ratio issue, the Indonesian government has promoted the use of solar energy-saving lamps. This study proposes a control strategy that adopts current reference time-based profiling for solar energy-saving lamps. For optimal energy consumption, the current reference profile is determined according to users’ daily energy requirements. From the aspect of user comfort, a gradual step reference profile is also introduced to provide a subtle change in lighting intensity level. The proposed control strategy can minimize energy consumption and optimize the operation durability of the system. The concept is verified by simulating four scenarios, the results of which …


Optimizing The Self-Healing Efficiency Of Hydrogel Encapsulated Bacteria In Concrete, Ricardo Hungria Apr 2022

Optimizing The Self-Healing Efficiency Of Hydrogel Encapsulated Bacteria In Concrete, Ricardo Hungria

LSU Master's Theses

Calcium carbonate precipitation through microbial means is a promising pathway for concrete self-healing technologies, mainly for its microcrack sealing attributes. The main goal of this project was to study and optimize the crack healing efficiency of hydrogel encapsulated bacteria in concrete. To achieve this purpose, Bacillus pseudiformus was implemented as the bacteria strain at a concentration of 108 cells/ml. This bacterium strain along with yeast extract was combined along with three different mineral precursors corresponding to magnesium acetate, calcium lactate, and sodium lactate. All these three precursors were evaluated at two concentrations (67.76 mM/l and 75 mM/l). For each …


Impulse, Spring 2022, University Marketing And Communications, Jerome J. Lohr College Of Engineering Apr 2022

Impulse, Spring 2022, University Marketing And Communications, Jerome J. Lohr College Of Engineering

Impulse (Jerome J. Lohr College of Engineering Publication)

2 | Ahmed Leads Construction and Operations Management
4 | Faculty News
8 | Kelley Steps Aside After 44 Years
12 | Boggs Retires From Mechanical Engineering
14 | Looking At Covid-19 Numbers
16 | Students Help College of Nursing
18 | Midwest Applied Materials Symposium Debuts
20 | Fourth Data Science Event Takes Place
24 | College Achievements
26 | Hard Work Pays Off
28 | Spotlight Shines on Students
30 | Mentoring Program Takes Off
32 | Robotics Club Busy With Activities
34 | The Numbers
36 | Brown, Sieve Honored
38 | Alumna Leads NASA Division
40 …


Development Of Cost-Effective High-Modulus Asphalt Concrete (Hmac) Mixtures Using Crumb Rubber And Local Construction Materials In Louisiana., Ibrahim A.I.E Elnaml Mar 2022

Development Of Cost-Effective High-Modulus Asphalt Concrete (Hmac) Mixtures Using Crumb Rubber And Local Construction Materials In Louisiana., Ibrahim A.I.E Elnaml

LSU Master's Theses

One of the emerging solutions to enhance the durability of asphalt pavements is the use of a French asphalt mix known as “High-Modulus Asphalt Concrete (HMAC).” This mix uses a hard asphalt binder, high binder content (about 6%), and low air voids content as compared to Superpave mixtures. The key objective of this study was to develop a cost-effective HMAC mixture using crumb rubber and local materials in Louisiana. To achieve this objective, four HMAC mixtures were prepared using two asphalt binders (PG 82-22 and PG 76-22 plus 10% crumb rubber) and two Reclaimed Asphalt Pavement (RAP) contents (20% and …


The Effect Of Sodium Polymethacrylate On The Rheology Of The Positive Paste And Performance Of The Lead-Acid Battery, Julian Kosacki, Dimitri Feys, Fatih Dogan Feb 2022

The Effect Of Sodium Polymethacrylate On The Rheology Of The Positive Paste And Performance Of The Lead-Acid Battery, Julian Kosacki, Dimitri Feys, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.


Examining The Effect Of A Chitosan Biopolymer On Alkali-Activated Inorganic Material For Aqueous Pb(Ii) And Zn(Ii) Sorption, Sukanta K. Mondal, Chenglin Wu, Felix C. Nwadire, Ali A. Rownaghi, Aditya Kumar, Yusuf Adewuyi, Monday Uchenna Okoronkwo Jan 2022

Examining The Effect Of A Chitosan Biopolymer On Alkali-Activated Inorganic Material For Aqueous Pb(Ii) And Zn(Ii) Sorption, Sukanta K. Mondal, Chenglin Wu, Felix C. Nwadire, Ali A. Rownaghi, Aditya Kumar, Yusuf Adewuyi, Monday Uchenna Okoronkwo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Biopolymers and alkali-activated materials have attracted a great deal of attention as adsorbents for the removal of heavy metal contaminants from aqueous solutions. Both materials are sustainable and feature unique properties, but biopolymers are relatively more expensive or difficult to prepare and exhibit low mechanical and surface properties, a narrow pH range, and thermal stability. In this study, hybrid adsorbents were prepared from both types of material, by alkali activation of low-cost fly ash precursors accompanied by incorporation of 0-2%mass chitosan biopolymer. Two types of alkaline activating solutions, NaOH and Na2SiO3, were employed to generate two sets of hybrid adsorbents …


Lateral-Torsional Instability And Biaxial Bending Of Imperfect Frp I-Beams, Jodi Knorowski, Stella B. Bondi, Zia Razzaq Jan 2022

Lateral-Torsional Instability And Biaxial Bending Of Imperfect Frp I-Beams, Jodi Knorowski, Stella B. Bondi, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

This paper presents the outcome of a theoretical and experimental study of the behavior of Fiber Reinforced Polymer (FRP) I-beams exposed to lateral-torsional instability or when subjected to biaxial bending. Laboratory experiments involved the application of vertical and horizontal static loads to a 4 x 4 x ¼ in. I-beam with various lengths and the resulting deflections were recorded. Governing biaxial flexure and torsion differential equations were modified to account for the presence of initial imperfections and subsequently solved using a central finite-difference scheme. The theoretical predictions of the beam behavior were found to be in good agreement with what …


Method For Reducing Warping Stresses In Torsionally Loaded I-Section Members Using Cfrp Plates, Mamadou Konate, Zia Razzaq Jan 2022

Method For Reducing Warping Stresses In Torsionally Loaded I-Section Members Using Cfrp Plates, Mamadou Konate, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

This paper presents a method for reducing warping normal stresses in torsionally loaded I-section members by utilizing carbon fiber-reinforced polymer (CFRP) plates. The CFRP plates are bonded to the outer surfaces of the flanges with a view to reducing warping normal stresses. The maximum warping normal stress in the flanges of a steel I-shaped member without the CFRP plates is compared to those obtained with the CFRP plates having various thicknesses. It has been found that the use of CFRP plates bonded to both flanges of the I-section result in a substantial reduction of the warping stresses. For the study …


Crystalline Analysis Of Geomicrobially-Induced Calcium Carbonate Precipitation In Sands Using A Surface Percolation Treatment Technique, Justin Edward Mulloney Jan 2022

Crystalline Analysis Of Geomicrobially-Induced Calcium Carbonate Precipitation In Sands Using A Surface Percolation Treatment Technique, Justin Edward Mulloney

UNF Graduate Theses and Dissertations

Ottawa 50/70 sand specimens and natural beach sand samples were treated using bio-augmented geomicrobies via a surface percolation technique. Testing was conducted on these specimens to determine how resultant calcium carbonate precipitation changed as a function of temperature, depth from the surface, and in the presence of magnesium. Specifically, x-ray Diffraction (XRD), a Scanning Electron Microscope (SEM), and Energy Dispersive X-ray Spectroscopy (EDS) were used to determine and quantify the presence of calcium carbonate and its associated phase. Results showed a direct relationship between temperature and precipitated calcium carbonate. In addition, as an unintended consequence associated with the treatment, ammonium …


New Type Of Lightweight Aggregate For Use In Structural Concrete, Jamal Khatib, Ali Jahami, Oussama Baalbaki, Adel Elkordi Dec 2021

New Type Of Lightweight Aggregate For Use In Structural Concrete, Jamal Khatib, Ali Jahami, Oussama Baalbaki, Adel Elkordi

BAU Journal - Science and Technology

This research studied the utilization of municipal solid waste incineration bottom ash (MSWI-BA) in lightweight coarse aggregate (LWC) production. A special method was followed to prepare the new aggregate to fully replace the normal aggregates (NWA) in concrete. The mechanical properties such as compressive strength, tensile strength, and elasticity modulus were investigated for the LWC concrete. Then, two beams were prepared; one from LWC and the other from NWC. The structural performance of beams made up of lightweight aggregates compared to normal aggregates was investigated. The results showed that this type of aggregates led to a 20% reduction in concrete …


Effects Of Bonding Pressure And Lamina Thickness On Mechanical Properties Of Clt Composed Of Southern Yellow Pine, Cody S. Bates Dec 2021

Effects Of Bonding Pressure And Lamina Thickness On Mechanical Properties Of Clt Composed Of Southern Yellow Pine, Cody S. Bates

Theses and Dissertations

This study produced cross-laminated timber panels at a range of four lamina thickness (5/8, 1, 1 1/8, and 1 1/4 inch) and three bonding pressures (50, 125, 200 psi), producing a total of 12 panels for mechanical testing. The goal of this study is to observe how the thickness and pressure trends affect the mechanical properties of CLT. Tests include flatwise bending, flatwise shear, internal-bond, and delamination. Results showed that bending MOE decreases as the panel thickness increases while bonding pressure had no significance. Bending MOR was less significant for the thickness and more significant for pressure compared to the …


Shear Strength Of Concrete Beams Made With Belitic Calcium Sulfoaluminate Cement, Caleb W. Chesnut Dec 2021

Shear Strength Of Concrete Beams Made With Belitic Calcium Sulfoaluminate Cement, Caleb W. Chesnut

Graduate Theses and Dissertations

The need for a cleaner alternative to portland cement (PC) concrete has led to increasing interest in alternatives to PC. Structural properties of most of these alternative cements are still an open research topic. One promising alternative cement is belitic calcium sulfoaluminate (BCSA) cement. The study presented in this paper investigated the shear strength, long term compressive strength, and carbonation in BCSA cement and PC concrete beams. A total of twelve eight-foot long beams were made; eight BCSA cement concrete beams and four PC concrete beams to be tested at various ages depending on cement type. Two beams of each …