Engineering Commons^™

High Strain Rate Analysis Of 3d Printed Concrete As Compared To Conventionally Cast Concrete, Weston Mcleod Thomsen

Masters Theses

"3D Printed Concrete (3DPC) is a developing method of construction that has advantages over conventional methods, including formwork reduction, complex geometry, and expedited construction. This technology has potential benefits for the military when considering the austere environments that forward operating bases are built in. This study aims to assess 3DPC applications in protective structures that protect critical assets from explosive blasts. These protective structures experience a high-strain rate response during blast loading of the structure, and the effects of this have yet to be analyzed in the literature concerning 3DPC. With the lack of prior research, the focus here will …

Lcc Mse Walls, Joel Smith

Theses and Dissertations

Lightweight cellular concrete (LCC) is mainly a mixture of water, cement, and foam bubbles. LCC generally has a cast density between 20-60 pcf and an air content between 49-84%. LCC is often used as a fill material because it has a low unit weight which reduces settlement. LCC is increasingly being considered as a backfill behind Mechanically Stabilized Earth (MSE) walls and embankments. Although engineers are using LCC in MSE walls or free face walls (MSE wall without the concrete panels or reinforcements), there is presently a lack of information regarding the performance and behavior of LCC to guide them. …

Compressive And Flexural Tensile Strength Impacts Of Aluminum Shavings In Concrete, Ian Smith

Construction Management

Concrete is one of the most utilized construction materials around the world, but new and cutting-edge methods are constantly pushing the envelope for concrete’s applications and feasibility as a construction material. Unfortunately, concrete has a general lack of resistance to bending and stretching. Studies have shown several successful attempts to enhance the mechanical properties of concrete through implementation of various admixtures and methods. Steel is widely considered the primary material capable of reinforcing concrete. This paper evaluates concrete’s change in strength of flexural tension and compression as a result of implementing aluminum as a reinforcing agent. To determine the full …

Slab Extension At Woods Humane Society, Corey K. Smith

Construction Management

Woods Humane Society is an animal shelter that provides pet rehabilitation and adoption services to San Luis Obispo and surrounding areas. The Woods’ facility contains a number of kennels for dogs as well as numerous outdoor, fenced-in, concrete exercise yards. These yards give dogs the opportunity to play outside a few times a day allowing them to get vital exercise. One of these yards on the south side of the property had an exterior fence that was offset from an existing slab on the interior of the fence by one foot. This was an issue for the shelter as dogs …

City Farm Slo ‘Garden For All’ – Shade Structure, Reed Aitken

Construction Management

Local non-profit, City Farm SLO, recently presented an opportunity for four Cal Poly Construction Management students to complete senior projects to construct their vision of a “Garden for All.” This paper will focus on the design, preconstruction, and construction processes necessary to complete the shade structure. The project will provide much needed shade to an outdoor classroom area where City Farm SLO hosts farm based education programs all year round. The completion of this senior project required thorough design, estimating, coordination, and construction efforts, while keeping safety and sustainable building practices at the forefront of every decision. This was particularly …

Optimal Concrete Mix Design And Finish For Skateboarding Performance, Lohgan Christoper Spencer

Construction Management

While concrete has been used in construction for hundreds of years, the introduction of concrete to skateboarding is a relatively new development. Concrete and concrete finishes are very well studied in the context of buildings and building design. Shotcrete is also very well understood as it has been in use for over 100 years. Because it is a relatively new sector of the industry, concrete skatepark construction is an area that has plenty of room for research and development. This research paper will describe the finish methods and mix designs used for concrete skatepark construction by leading skatepark construction companies …

Effects Of Admixes On The Compressive Strength Of Permeable Concrete, James T. Lyon

Construction Management

Compression tests were performed on three samples of permeable concrete to evaluate the effects of admixes on a conventional permeable concrete. The first mix served as the control, representing a standard permeable concrete sample. The second mix replicated the control but added a small amount of fiberglass, accounting for 0.5% of the cement's weight. The third mix again mirrored the control and incorporated the manufacturer's recommended amount of a water reducing admix known as "Reducer 555". The objective of testing the two new mixes against the control mix was to evaluate the potential increase in ultimate compressive strength. Four 6” …

Optimization Of The Self-Healing Efficiency Of Bacterial Concrete Using Impregnation Of Three Different Precursors Into Lightweight Aggregate, Omar Omar

LSU Master's Theses

Concrete is the most broadly used construction material; thus, developing sustainable concrete is essential to decrease greenhouse gas (GHG) emissions from concrete production. Implementation of self-healing concrete technologies is a promising approach to enhance the durability and sustainability of the transportation infrastructure. Among these technologies, bacterial concrete has the potential to seal microcracks through microbial induced calcite precipitation (MICP). Bacterial protection is essential to ensure the viability of this technology due to concrete’s harsh environment. Additionally, the success of this technology depends on the presence of an adequate mineral precursor compound and nutrient for the bacteria. As such, the main …

Development Of Self-Stressing Ultra High-Performance Concrete Using Expansive Chemical Admixtures, Lane Edwards

Graduate Theses and Dissertations

This study investigated the effects of expansive chemical admixtures on ultra-high performance concrete (UHPC) and self-stressing mechanisms. A literature review was performed to determine different types of expansive admixtures for feasibility of the self-prestressing concept. Ultimately it was decided that type-k cement, made by combining Komponent admixture with conventional UHPC, was the most suitable option due to its effects on wet and hardened concrete properties. Mix designs with varying amounts of Komponent were developed to test the effects the admixture had on various properties. Tested properties included, workability, compressive strength, expansion, short-term shrinkage, long-term shrinkage, and developed prestress. The development …

The Influence Of The Addition Of Recycled Asphalt Shingles On The Compressive Strength Of Concrete, William E. Webb

Honors College Theses

The purpose of this study is to explore the effect of recycled asphalt shingles (RAS) as an additive on the compressive strength of concrete. This was accomplished by designing a concrete mix and creating 4” by 8” cylindrical test specimens containing 0, 5, 10, and 15 percent RAS by weight. The compressive strength was measured through axial loading until failure utilizing a compression testing apparatus. With these results, a relationship between the content of RAS and compressive strength was able to be developed, giving insight as to how RAS could be used in concrete mixes in the future. This study …

Adiabatic Temperature Rise And Durability Performance Of Slag Blended Concrete, Hai Zhu

USF Tampa Graduate Theses and Dissertations

Performance and durability of slag blended concrete was investigated in this study focusing on slag and cement characteristics. Seven slags with variable Al2O3 content, Al2O3/MgO ratio and fineness were selected for investigation. The eight selected cements included ASTM Type I, Type I(HA), Type II(MH), Type II(MH)(HA), and Type IL(10 and 14). Cementitious materials studied here were subjected to a battery of tests including physical, chemical and mineralogical characterization. Performance and durability testing included heat of hydration measurements, sulfate optimization, external sulfate resistance, adiabatic temperature rise and chloride ingress.

Adiabatic temperature rise was assessed on 60% slag blended concrete, using Type …

United Methodist Children Center Drain Project, Andy Abdelnour

Construction Management

The United Methodist Children Center in San Luis Obispo is a preschool for young children in our community. Some of these students are the children of Cal Poly faculty and staff. The previous drain was not draining water properly and was uneven with bumps and dips that became a hazard for the children. Children would trip, fall, and hurt themselves on the drain. A team of two Cal Poly Construction Management students Ethan Lin and Andy Abdelnour worked together to estimate, design, coordinate, demolish, and construct a new section of the drain that would be safe for the students. The …

Nondestructive Evaluation Of Structural Defects In Concrete Slabs, Ehsanul Kabir

Electronic Theses and Dissertations

Nondestructive testing (NDT) is a reliable method for determining the structural integrity of new and old construction and understanding the condition of structural defects. It is widely acknowledged that the interpretation of nondestructive evaluation (NDE) has a significant impact on the reliability and consistency of this technology. However, NDT data acquisition remains subjective and heavily dependent on the operator’s knowledge and expertise. As a result, there are still issues to be resolved regarding the imaging and diagnostic procedures for NDT-based concrete inspection. NDT methods such as ground penetrating radar (GPR), and impact-echo (IE), have been extensively used to inspect concrete …

Feasibility Of Applying Motion Magnification In Subsurface Defect Detection For Concrete And Fiber-Reinforced Polymer Specimens, Nagavardhani Malineni

Graduate Theses, Dissertations, and Problem Reports

Irrespective of size and complexity, every civil infrastructure needs certain scrutiny regarding its structural health to ensure its serviceability during its lifetime. In olden times such scrutiny was done with the aid of destructive testing methods using sensors that required cumbersome and expensive installations and led to the destruction of at least part of the tested specimen. However, in recent times, many non-destructive methods, such as acoustic emission testing, electromagnetic testing, and laser testing methods have emerged, leaving the specified tested specimen undisturbed. With the advancement in sensor technology like motion magnification and with the help of access to high-speed …

A Study On Early Age Properties Of Concrete For Precast And 3d Printing, Debalina Ghosh

Doctoral Dissertations

Concrete is the second-most consumed material, leading the global Portland cement production of 4.1 billion tons in 2020 and 5-8% of global Carbon dioxide (CO₂) emission annually. As with any other material and practice, the construction industry is also ever-changing to meet market demand, evolving technology, and resource limitation. In the case of concrete construction, one of the main concerns is the lack of automation. In the last few decades, some new construction methods have risen to address this concern. Some of these economic and successful practices are precast construction, self-compacting concrete (SCC), and 3D printing of concrete(3DPC). …

Flexural Bond Strength Of Masonry Assemblies With Lightweight Grout, Benjamin L. Hiner

All Theses

Lightweight grout has many potential benefits in masonry construction, including minimizing mass, improving thermal performance, and potentially reducing shrinkage cracking via internal curing. However, insufficient testing of masonry assemblies with lightweight grout has been conducted to suggest appropriate design modification factors akin to the lambda factor in ACI 318-19. The objective of this paper is to study the tensile bond behavior of masonry assemblies grouted with lightweight grout and to suggest appropriate equations for predicting design capacity. A moment couple test is designed specifically for grouted masonry assemblies and has additional capacity compared to the traditional ASTM 1072 bond wrench …

Shape Deformities In Recycled Concrete As A Substitute Aggregate In Concrete, Carson D. Timmerman

Construction Management

Concrete is a universal material that is used widely across the construction industry. Within a standard concrete mix, a fine aggregate and a coarse aggregate are added to the mix design to help with solidity and compressive strength in the mixture. The admixtures, additives, slump, and mix ratios will differ based on the compressive strength you're trying to attain. This paper directly reflects the results of the differences between shapes in recycled concrete used as a coarse aggregate substitute in concrete mixes. As the construction industry grows, so does outreach towards sustainability and reusing materials anywhere the industry can. Testing …

Evaluating Smartrock Temperature Sensor Performance In Measuring Concrete Strength, Jack Dasch

Construction Management

Concrete testing is one of the most important parts of the concrete placement process. Traditionally, this is done through the use of 6x12 cylinders cured in a lab that are broken at various stages of the curing process. These cylinders are not necessarily representative of the in-situ concrete because of their differing curing conditions- indoors versus exposed to the elements. Wireless temperature sensors, like Giatec’s SmartRock, have the potential to determine concrete strength based off the temperature of the placed concrete over time, thus eliminating the need for cylinder breaks. Once calibrated to the specific mix design, these wireless sensors …

Differing Moisture Content In Concrete And Mitigation Methods: Research Of Sacramento, Taylor S. Tonda

Construction Management

The city of Sacramento and its concrete foundations face one of the most challenging conditions in the flooring industry, high RH Moisture. RH Moisture or Relative Humidity Moisture is one of the main causes for flooring systems to fail. The source of High RH Moisture consists of surrounding geographic features like rivers, flood plains, and elevation, as well as improper or nonexistent use of a vapor barrier beneath the concrete foundation. Mapping and other data is used to support these claims. If a flooring system is not properly prepared for high RH Moisture levels, issues such as bubbling, delamination, and …

Construction Of Modular Concrete Footings For Use In Cal Poly’S High Bay Laboratory, Tyler W. Giddens

Construction Management

This project-based senior project had the end goal of creating two concrete modular foundations that can be used in the High Bay Laboratory for testing procedures. The concrete modular blocks are 6’ long by 3’ wide, and 1.5’ tall. The foundations each held 100 embeds. Each embed serves as an anchor point for various attachments for testing purposes. This was an interdisciplinary project amongst two CM students and one ARCE student. The ARCE student was responsible for the design of the blocks, encompassing the formwork and the rebar. The CM students were responsible for estimating, scheduling, and the construction of …

The Effects Of Recycled Waste On Concrete Mixture Properties, Noral Hadbawi

Master of Science in Civil Engineering Theses

Recent years have seen an exponential increase in plastic product consumption worldwide. Manufacturing, and individuals rely on plastics in almost every aspect, as a result, a negative impact on the environment is detected due to the large quantities and low biodegradability of plastic waste. The massive amount of plastic waste and end-of-life tires produced annually required a vast area of landfills, which became a major concern far and wide. To address these issues, an eco-friendly approach consisting of incorporating plastic and rubber waste into engineering applications, such as plastic concrete, and rubberized concrete was proposed. A primary objective of this …

Sustainable Concrete And Its Current Stance In The Construction Industry, Morgan Hailey Gawle

Construction Management

Concrete is currently the second most consumed resource used in the world and the production of this material, mainly the production of cement, contributes to a little over 8% of carbon dioxide emissions globally. The concept of sustainable concrete is rapidly surfacing within the construction industry as environmental issues and concerns like global warming and climate change continue to worsen. Scientists have been and continue to consistently conduct studies to test if sustainable concrete is a possible solution to reducing carbon dioxide and greenhouse gas emissions that come straight from the construction industry. But some construction companies have concerns that …

Performance Evaluation Of Glass-Fiber Reinforced Cement-Free Geopolymer Concrete, Mohammad Zuaiter

Theses

The alkali-activation of aluminosilicate materials produces a geopolymer binder that promises to be a sustainable replacement to cement in concrete. Yet, such concrete has experienced brittle behavior and poor resistance to cracking. As a means of improving its performance, this research assesses the feasibility of utilizing glass fibers in slag-fly ash blended geopolymer concrete for structural applications. A blend of slag and fly ash served as the binding material. Two types of glass fibers were used individually or as a hybrid combination. Type A and B glass fibers had similar properties but different lengths of 24 and 43 mm, respectively. …

Cvaf: Service Dog Kennel Construction, Luke A. Terrio, Spencer Allen

Construction Management

The California Veterans Assistance Foundation Service Dog Kennel Construction project gave back to our country’s veterans by constructing new kennels for their service dogs. The previous kennel on the veteran residential site needed an upgrade due to the increased number of service dogs at the shelter. A team of two Cal Poly Construction Management students consisting of Spencer Allen and Luke Terrio worked to design, estimate, coordinate, and construct a new kennel structure for the site. The roles were divided in the project between the preconstruction and construction phases. During pre-construction Spencer’s role was to schedule the job and create …

Cvaf: Service Dog Kennel Construction, Spencer G. Allen

Construction Management

The California Veterans Assistance Foundation Service Dog Kennel Construction gave back to our country’s veterans by constructing new kennels for their service dogs. The previous kennel on the veteran residential site needed an upgrade due to the increased number of service dogs at the shelter. A team of two Cal Poly Construction Management students consisting of Spencer Allen and Luke Terrio worked to design, estimate, coordinate, and construct a new kennel structure for the site. The roles were divided on the project between the preconstruction and construction phases. During preconstruction Spencer’s role was to schedule the job and create the …

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.

Persistence And Mitigation Of Pfas Within Concrete Stormwater Drainage Infrastructure, Jason R. Mcdonald

Theses and Dissertations

The persistence, fate, and transport of per- and poly-fluoroalkyl substances, which have been shown to have adverse effects on human health, have been previously studied in environmental media such as soils and groundwater. This study investigates concrete, a medium that is rarely studied but frequently present in instances where PFAS originating from AFFF releases and spills have occurred. Used heavily throughout aviation firefighting, AFFF poses environmental hazards due to the length of PFAS degradation and toxicological implications, thus its classification as a forever chemical. From the very limited reports to date, studies have suggested very slow release from concrete, potentially …

Thermal Testing And Simulation Of Lunar And Martian Isru-Based Materials, Andres Campbell

All Undergraduate Theses and Capstone Projects

Upon the eventual return of humans to the lunar surface, leveraging local resources to construct landing pads and other infrastructure is an essential component to minimize cost and risk. The inability to accurately model landing and launch scenarios to predict damage to lunar structures poses risks to astronaut and equipment safety. The following experiment is an investigation of using simulation software and temperature sensors to model lunar and Martian regolith simulant-based concrete exposed to thermal loads. The basis of this experiment is built upon standards defined by the American Society for Testing and Materials, the fundamental axioms of structural health …

Strain And Temperature Measurement From Distributed Fiber Optic Sensors In Performance-Based Fire Engineering, Yanping Zhu

Doctoral Dissertations

"Strain and temperature measurement of steel and concrete structures under fires is critical to the understanding of structural performance yet historically challenging due to a significant gap in measurement science. This Ph.D. study characterizes in six parts low-cost distributed fiber optic sensors and applies them to strain, and temperature measurements based on Rayleigh and Brillouin light scattering. The first part aims to quantify the Rayleigh scattering based measurement accuracy of distributed fiber optic sensors under a heating-holding load protocol and characterize the effect of polymer coating on the sensors as the polymer softens and melts at elevated temperatures. The second …

A Comparison Of Common Structural Materials, Molly Green

Williams Honors College, Honors Research Projects

This report will compare structural steel, concrete, and lumber through the lenses of mechanical properties, design process, cost, and environmental impact. Steel is a versatile, strong, and lightweight material that comes at a premium price – both financially and environmentally. It is the most expensive material of the three included in this report. This is largely due to its complex manufacturing process that is also responsible for a significant amount of the world’s carbon dioxide emissions. Concrete is significantly less expensive than steel, but the carbon dioxide emissions from manufacturing are approximately equal. Concrete also only performs well in compression …