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 …

Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Evaluating Structural Build-Up At Rest Of Mortar And Concrete, Sofiane Amziane, Kamal Khayat, Mohammed Sonebi, Arnaud Perrot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Paper Presents the Results of a Round-Robin Testing Program Undertaken by RILEM TC-266-Measuring Rheological Properties of Cement-Based Materials in May 2018 at the Université D'Artois in Bethune, France. Seven Types of Rheometers Were Compared; They Consisted of Four ICAR Rheometers, Viskomat XL Rheometer, EBT-V Rheometer, Sliding Pipe Rheometer (SLIPER), RheoCAD Rheometer, and 4SCC Rheometer, as Well as the Plate Test. This Paper Discusses the Results of the Evolution of the Static Yield Stress at Rest of Three Mortar and Five Concrete Mixtures that Were Determined using Two ICAR Rheometers, Viskomat XL, and EBT-V Rheometers, as Well as the Plate …

Utilizing Waste Latex Paint Toward Improving The Performance Of Concrete, Mohamed Leithy, Eslam Gomaa, Ahmed A. Gheni, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper, incorporating the waste latex paint (WLP) into the conventional concrete as a partial replacement of sand to improve its durability was investigated. The fresh and hardened characterizations, in addition to the durability of concrete, were examined. The slump test was used to evaluate the fresh properties, while the hardened properties were evaluated through the volume of voids and absorption rate, in addition to the compressive, splitting tensile, and flexural strengths tests. The durability performance was evaluated by the surface resistivity, bulk electrical resistivity, as well as freeze and thaw resistance tests. The results showed a reduction in …

Nonlinear Impact-Echo Test For Quantitative Evaluation Of Asr Damage In Concrete, Clayton Malone, Hongbin Sun, Jinying Zhu

Department of Civil and Environmental Engineering: Faculty Publications

Nonlinear acoustic methods demonstrate high sensitivity for concrete damage evaluation. Among these methods, nonlinear resonance acoustic methods have been widely used in laboratory tests on small scale test samples. In this study, a nonlinear impact-echo (IE) method was proposed for concrete damage evaluation, in which the IE frequency shift was measured at different impact force levels. The nonlinear IE test is similar to the nonlinear impact resonance acoustic spectroscopy (NIRAS) test in the experimental setup and analysis method. How- ever, the nonlinear IE test excites a local thickness resonance mode of a member instead of the global resonance vibration. Therefore, …

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 …

Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Rheometers, Mixtures And Procedures, Dimitri Feys, Mohammed Sonebi, Sofiane Amziane, Chafika Djelal, Khadija El-Cheikh, Shirin Fataei, Markus Greim, Irina Ivanova, Helena Keller, Kamal Khayat, Laurent Libessart, Viktor Mechtcherine, Ivan Navarrete, Arnaud Perrot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Recent developments in understanding the rheology of mortar and concrete as well as applying this understanding in the practice of construction necessitate an accurate assessment of materials' rheological properties. It is well known that different rheometers for mortar and concrete deliver different results, as this was shown over 15 years ago in two measuring campaigns comparing concrete rheometers. Considering newly developed rheometers, including those to evaluate interface rheology and structural build-up at rest, as well as additional measurement procedures and data interpretation techniques, a new comparison campaign was carried out in 2018 at the Université d'Artois, in Bethune, France. This …

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 …

Editorial: Ultra-High Performance Concrete: Computation And Simulation Methods, Xinpeng Wang, Yitong Ma, Dongshuai Hou, Hongyan Ma, Yue Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

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 …

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 …

Concrete Mix Design Using Abrams And Bolomey Methods, Salem Abdelgader, Marzena Kurpinska, Hakim Abdelgader, Jamal Khatib

BAU Journal - Science and Technology

This research studied concrete design methods. To design concrete using two methods, including the Abrams law and the modified Bolomey method. Concrete with assumed compressive strength 25, 30, 35, 40, and 45 MPa was researched. The research was conducted in the laboratory using two types of samples: cubic 15x15x15cm for compressive strength tests and cylinders ϕ-15cm, h-30cm for the splitting strength tests using the Brazilian method.

The analysis of the cement content in the composition of 1m3 of the mixture showed very large differences depending on the calculation method used. The cement content calculated according to the Abrams method ranged …

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 …

Review Of Fly-Ash As A Supplementary Cementitious Material, Nikki Shaji, Niall Holmes Dr., Mark Tyrer

Conference papers

This paper presents a review of fly-ash as a Supplementary Cementitious Material (SCM) in concrete in terms of its effects on hydration and durability. The climate change agenda has focused the cement and concrete industry on using low embodied CO2 materials and much effort has been made on incorporating industrial by-products into cement as SCMs. With worldwide cement production (circa 4 billion tonnes) currently accounting for approximately 8% of global CO2 emissions and 7% of industry energy use, the use of suitable SCMs to partially replace cement in concrete is extremely important. However, while coal-fired power stations are in the …

The Degradation Of Concrete Tunnel Wall Panels: A Case Study, Christian Paglia

International Conference on Durability of Concrete Structures

Concrete panels are often used along tunnel walls for technical and aesthetic purposes. Generally, the environment in contact with such materials is aggressive. Emission gases from the vehicles, sulphates, chlorides coming from the winter salt spreading, high temperature and humidity promote an acceleration of the deterioration phenomena. In this work 30 years old concrete panels placed along a 16 km long highway tunnel across the Alps were investigated with respect to their durability. The focus was given to the tunnel entrance zone. This region of the tunnel exhibited a critical environment with respect to the durability of the cementitious material …

Finite Element Modeling Of Thermal Effect On Airport Slabs, Chuanyue Shen

International Conference on Durability of Concrete Structures

A sub-ground tunnel connecting two concourses of a terminal at Chicago O’Hare International Airport suffered from water leakage. The airport engineers suspected that the problem was caused by high stresses impinging on the tunnel structure by the pavement sections above the tunnel, acting to damage joints and waterproofing membranes that should have prevented such leakage. To provide a fundamental solution to this problem while minimizing the interference with airport operation, a repair strategy needs to be determined based on a clear understanding of the root cause. A preliminary field inspection confirmed that the concrete pavement slabs moved significantly when ambient …

Applications Of Stretching Technique And Time Window Effects On Ultrasonic Velocity Monitoring In Concrete, Bibo Zhong, Jinying Zhu

Department of Civil and Environmental Engineering: Faculty Publications

Coda wave interferometry (CWI) has been used to measure the relative wave-velocity change (dV/V) caused by small changes in materials. This study uses the stretching processing technique which has been used for CWI analysis to investigate velocity changes of direct longitudinal (P) wave, direct shear (S) wave, and coda wave in concrete by choosing different time windows of ultrasonic signals. It is found that the obtained wave-velocity change depends on the time window position, because the relative contribution of P wave and S wave is different in each signal window. This paper presents three experimental scenarios of velocity …