Structural Materials Commons^™

Case Studies Of Cavity And External Wall Insulation Retrofitted Under The Irish Home Energy Saving Scheme: Technical Analysis And Occupant Perspectives, Aimee Byrne, Gerard Byrne, Garrett O'Donnell, Anthony Robinson

Articles

The residential sector represents 27% of primary energy consumption in Ireland. This paper examines the case study of the Irish government’s national grant scheme to encourage energy efficiency retrofit in private housing. That is the Home Energy Saving (HES) Scheme, later rebranded the Better Energy: Homes (BEH) Scheme. The methodology involved monitoring several homes immediately before and after retrofit alongside discussions with occupants. The examination focused on specific measures commonly introduced through the HES/BEH programme − cavity and external wall insulation. It has been found that a significant decrease in heat loss through the walls was measured in all cases. …

Evaluating A New Cem Iii/A Cement For Concretes Exposed To Harsh Acid Rich Environments, David Thompson, Niall Holmes, John Reddy

Conference papers

The Irish Annex to the European specification, performance, production and conformity of concrete, IS EN 206, recommends CEM III/B cement for acid rich environments containing between 66 to 80% GGBS. However, BS 8500, the UK annex to EN 206 and the British Research Establishment (BRE) Special Digest 1, recommends CEM III/A cement with a GGBS range of 36-65%. This project investigated the performance of a new CEM III/A cement produced by Ecocem Ireland in concretes exposed to such environments using an extensive suite of laboratory tests.

In Ireland, up to €5.8bn will be invested to provide fresh drinking water and …

Underwater Explosion Energy Dissipation Near Waterborne Infrastructure, Paul R. Smith

Theses and Dissertations--Civil Engineering

Underwater explosions pose a significant threat to waterborne infrastructure though destructive pressure waves that can travel significant distances through the water. However, the use of bubble screens can attenuate the peak pressure and energy flux created by explosions to safe levels. This study investigates the prediction of pressure wave characteristics based on accumulated data, the damage potential of underwater explosions based on applied loads and effective material strength, and the bubble screen parameters required to prevent damage. The results were compiled to form a procedure for the design and implementation of a bubble screen the protection of waterborne infrastructure.

Preliminary Investigation Into The Rate Of Carbonation Of Concrete Blocks Under Normal Production Yard Conditions, Aimee Byrne, Eanna Nolan

Conference papers

The release of CO2 from calcination during the manufacture of cement can be partially or fully offset by the CO2 it naturally absorbs during its lifetime. This paper reports results from a preliminary investigation into the rate of carbonation in concrete blocks stacked in a production yard over a period of 6 months. The blocks were stacked in a normal manner under natural exposure conditions. Carbonation progress was determined by splitting the blocks and spraying the freshly exposed surface with a phenolphthalein solution at intervals over the test period. It was found that the rate of the carbonation front progression …

Methodology For Analyzing Epoxy-Cnt Phononic Crystals For Wave Attenuation And Guiding, Madhu Kolati

Dissertations, Master's Theses and Master's Reports

Phononic crystals (PhnCs) control, direct and manipulate sound waves to achieve wave guiding and attenuation. This dissertation presents methodology for analyzing nanotube materials based phononic crystals to achieve control over sound, vibration and stress mitigation. Much of the analytical work presented is in identifying frequency band gaps in which sound or vibration cannot propagate through these PhnCs. Wave attenuation and mitigation analysis is demonstrated using finite element simulation. Engineering principles from current research areas of solid mechanics, solid-state physics, elasto-dynamics, mechanical vibrations and acoustics are employed for the methodology. A considerable effort is put to show that these PhnCs can …

Heterogeneous Thermal Effects On Structural-Grade Steel, Eric Wickersham

Williams Honors College, Honors Research Projects

The AISC Steel Construction Manual covers structural steel design while at atmospheric and elevated temperatures. The manual does not, though, cover what happens to the steel after it has cooled from elevated temperatures. To fill in this knowledge gap, A36 steel was studied with respect to three main criteria: time, temperature, and cooling. Time was sub-divided into a standard burn (17-20min) and a prolonged burn (90min). Temperature was sub-divided into an average burn (600-800⁰F) and an extreme burn (>1200⁰F). To reach such temperatures, a forge was constructed and used during the burning process. Cooling was sub-divided into standard (air …

An Overview Of The Development Of Cement-Based Batteries For The Cathodic Protection Of Embedded Steel In Concrete, Aimee Byrne, Niall Holmes, Brian Norton

Conference papers

This paper presents an overview of the cement-based batteries developed in DIT for use in the cathodic protection of embedded steel in reinforced concrete undergoing chloride-induced corrosion. Cathodic protection delivers an external current (approximately 20mA per m2 of embedded steel) which effectively polarises the internal current generated during corrosion. The batteries developed in DIT comprise of a cement-based electrolyte containing different additives including sand, aggregate, salts, carbon black and plasticiser with protruding anode and cathode metal plates. These batteries produced an initial electrical output of 1.5V and 23mA through a 10 resistor as measured using data acquisition units and a …

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 …

A Comparison Of The Bond Behavior Of Pbo-Frcm Composites Determined By Double-Lap And Single-Lap Shear Tests, Lesley Sneed, T. D'Antino, C. Carloni, C. Pellegrino

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the results of an investigation on the bond behavior and stress-transfer mechanism of polyparaphenylene benzo isoxazole (PBO) fiber-reinforced cementitious matrix (FRCM) composites bonded to a concrete substrate using double-lap and single-lap shear tests. Results of double-lap shear tests with different composite bonded lengths and widths are presented and compared with those from single-lap shear tests previously reported by the authors. The idealized load response developed from single-lap shear tests is found to characterize the response of the composite in double-lap shear tests, although with a few key differences. With the double-lap shear test, load redistribution among the …

Influence Of Warping On Stress For Restrained Concrete Slabs: For Application To Crcp, Corey M. Beck, W. Jason Weiss, Nathan T. Todd

The Summer Undergraduate Research Fellowship (SURF) Symposium

Continuously-reinforced concrete pavement (CRCP) is widely used in transportation system because of its low maintenance requirement. However, the need for large volumes of steel creates a high cost for new construction. The Illinois Tollway is preparing to substantially renovate highways in and around Chicago and this work seeks to understand how concretes of varying mixture designs can be made thinner by reducing the amount of built-in stress. The experiment examines warping in beams subjected to various degrees of restraint, in an effort to assess effectiveness at reducing warping in continuously reinforced concrete pavements. Value added methodologies such as internal curing …

Examining The Hydration And Mechanical Properties Of Cement Paste Containing Cellulose Nanocrystals, Yvette Valadez-Carranza, Charles Y. Chiu, W. Jason Weiss, Pablo Zavattieri, Jeffrey P. Youngblood

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cellulose nanocrystals (CNCs) are a nano-scaled particulae material that has been shown to improve strength in cementitious pastes. One advantage of CNCs compared to other nano-materials is that CNCs are renewable and sustainable. The objective of this investigation is to investigate the influence of additional alkali content on the behavior of CNCs in cement paste. This work evaluates flexural and compressive strength as a function of heat of hydration—which measures the extent of reaction. Previous mechanical tests on cement paste containing cellulose nanocrystals (CNCs) have shown CNCs to improve the flexural strength of cement paste by approximately 30%. Isothermal calorimetry …

Prediction Of Shear Strength And Ductility Of Cyclically Loaded Reinforced Concrete Columns Using Artificial Intelligence, Nicholas Gordon

UNLV Theses, Dissertations, Professional Papers, and Capstones

The shear strength and deformation capacities of reinforced concrete (RC) columns are governed by a multitude of variables related to material properties of the steel and concrete used in the design and construction of the columns. Predicting performance of RC columns using design variables is a complex, non-linear problem. The prediction of shear strength and ductility for these types of structural members has historically been performed using empirically or semi-empirically derived formulae based on experimental results. The introduction of cyclical lateral loading, such as the forces imposed on a structure during an earthquake, can result in severe degradation of shear …

Early-Age Hydration Studies Of Portland Cement, Fengjuan Liu

Electronic Theses and Dissertations

Our current knowledge on cement hydration during setting is based on the discrete observation of hydrated paste. An advanced micro/nano-level technique which can perform the in-situ observation on the continuous hydration of cement paste is demanded. In this study, Raman spectroscopy (RS) was chosen as such a method to continuously investigate wet pastes. The objective of this research is to explore the hydration process and microstructural development of fresh pastes with this technique. This research was conducted in three phases. First, the RS analysis was used to continuously observe the cement hydration from 20 minutes after mixing to 9 hours. …

High Strength Steel Fiber Reinforced Flow-Able Or Scc Concrete With Variable Fiber By Volume Fractions For Thin Plate And Shell Structures, Abebe Berhe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study is to incorporate discrete, short, mechanically deformed, small diameter steel fibers into high strength concrete with f'c > 70 MPa (10 ksi) in an attempt to reduce and partially eliminate the need for steel rebar in concrete construction. By introducing steel fibers to high strength concrete mixture, the overall tensile, compressive and shear strength of the mixture can be improved immensely thus, replacing portions or major parts of the longitudinal, temperature and shrinkage reinforcements. The reduction or elimination of longitudinal and transverse reinforcements in the construction of structural or non-structural members can result in savings in …

Finite Element Analysis Of Bolted Connections Under Fire, Ke Liu, Qiaqia Zhu, Amit H. Varma

The Summer Undergraduate Research Fellowship (SURF) Symposium

Over the course of human history, fire disasters are one of the major catastrophes that causes loss of lives and properties. In order to ensure building safety against fire, civil engineers seek to understand the behavior of structures at high temperatures. Moreover, they need to study the behavior of bolted connections, given the important role it plays in steel structures. Sarraj (2007) proposed a plate-bearing computational model used to describe this behavior; however, it has never been experimentally verified. Prior to this specific project, a series of single-bolted connection tests at 400°C and 600°C were conducted in the Bowen Laboratory …

Bio-Inspired Helicoidal Composites: 3d Printing And Experiments, Michael E. Jones, Pablo Zavattieri, Nobphadon Suksangpanya

The Summer Undergraduate Research Fellowship (SURF) Symposium

Materials that are impact resistant enough for personal protection in sports, transport, and combat are not also lightweight, strong, tough, and impact tolerant. Nature can provide inspiration for novel materials that can meet these needs. The hierarchical composite of the stomatopod’s, or mantis shrimp’s, dactyl club has been shown to have high impact resistance and damage tolerance due to its helicoidal fiber reinforcement(1,2). Analyzing helicoidal composites of different pitch angles (angles between adjacent rows of fibers) under quasi-static, displacement-controlled loading has provided insights into the fracture mechanisms of the composite structure and how they affect the macroscopic properties of the …

Characterizing The Pore Structure Of Carbonated Natural Wollastonite, Chiara Villani, Robert Spragg, Raikhan Tokpatayeva, Jan Olek, W. Jason Weiss

International Conference on Durability of Concrete Structures

This paper focuses on examining the pore structure of a cementitious paste made with a calcium silicate (wollastonite) that reacts with carbon dioxide and water to form a hardened solid. The pore structure of the hardened solid has been characterized using vapor sorption and desorption, low-temperature differential scanning calorimetry (LT-DSC), and scanning electron microscopy (SEM). The total porosity was also measured using mass measurement in oven-dry and vacuum-saturated conditions. Evidence exists that support the hypothesis that the solid has two main pore sizes: large macropores (>10 nm) appear to form between the initial calcium silicate particles and small micropores …

Experimental Investigation Of Lateral Cyclic Behavior Of Wood-Based Screen-Grid Insulated Concrete Form Walls, John Stuart Garth

Dissertations and Theses

Insulated concrete forms (ICFs) are green building components that are primarily used for residential wall construction. Unlike most polystyrene based ICF variants, the Faswall ICFs used in these experiments were significantly denser because they were made from recycled wood particles and cement. The current design approach for structures constructed with this type of wall form only allows the designer to consider the contribution of the reinforced concrete cores. Previous research has shown that this approach may be conservative. This project experimentally evaluated the lateral structural response of these types of grid ICF walls under increasing amplitude of in-plane cyclic loading. …

The Effect Of Clay, Cement And Fibers On The Strength And Durability Of Compressed Earth Blocks, Wyatt Adair Banker-Hix

Master's Theses

This Thesis examines the effect of soil characteristics, cement content and fibers on the strength and durability of compressed earth blocks (CEBs). This work expands on the available information regarding the constituent properties which affect the compressive and tensile strengths and durability of CEBs. Additionally, little research on the subject of synthetic fibers and their effect on strength and durability of CEBs is available and this work provides an initial study in this area.

To study the effects of fibers, as well as confirm the trends of previous research regarding the effects of clay and cement, 27 unique batches of …

Post-Fracture Capacity Of Railroad Flat Car Bridges, Teresa L. Washeleski

Purdue Road School

Railroad flatcars (RRFCs) are a convenient option to replace existing deteriorating bridge structures on low-volume roads. They are typically used as the bridge superstructure by placing two or more flatcars side-by-side to achieve the desired bridge width. Utilizing RRFCs as a bridge allows for rapid construction and greater cost savings compared to traditional practices. These benefits make them an attractive solution for rural communities in Indiana, as well as other states.

Uncertainty remains about the response under higher loads than could be easily achieved in the field and the level of redundancy of railroad flatcar bridges. Using RRFCs as bridges …

Post-Failure Capacity Of Built-Up Steel Members, Matthew H. Hebdon

Purdue Road School

Mechanically fastened built-up steel members have long been known to possess internal member redundancy and, as a result, multiple load paths which can be exploited to increase their functional life. Internal redundancy provides the ability to resist total member failure in the event of a fracture of an individual component. However, there is little experimental data in the literature regarding post-fracture capacity in terms of strength and subsequent fatigue life. The experimental study currently underway will provide needed information on parameters that affect the ability of built- up members to arrest a fracture as well as the available remaining fatigue …

Mechanical And Transport Properties Of Alkali-Activated Natural Pozzolans As Sustainable Binders, Brittany Radke

Calvert Undergraduate Research Awards

OPC production accounts for 5 to 7% of the global carbon dioxide (CO₂) emissions, contributing to global warming. The desire to reduce CO₂ emissions and produce more durable concrete has given impetus to search for new binders. It is suggested that alkali-activated natural pozzolans have the potential for use as a sustainable replacement for OPC in concrete.

The current study presented herein evaluated fresh, mechanical, and transport properties of alkali-activated natural pozzolan mortars containing various concentrations of sodium hydroxide solutions as an alkaline activator. To this aim, alkali-activated natural pozzolan mortars were made with concentrations of sodium …

Development Of Cementitious Materials For Adhesion Type Applications Comprising Calcium Sulfoaluminate (Csa) Cement And Latex Polymer, Joshua V. Brien

Theses and Dissertations--Civil Engineering

The objective of this research was to develop high performing polymer modified calcium sulfoaluminate (CSA) cement materials for use in applications requiring superior adhesion characteristics. Little information is available describing interactions of CSA cement containing minor phase tri-calcium aluminate (C₃A) with commonly used admixtures. Given the scarcity of information, a basic approach for developing cementitious materials was followed. The basic approach consisted of four tasks: cement design, admixture design, polymer design and testing developed materials. The iterative, time consuming process is necessary for understanding the influence of specific constituent components on overall system behavior. Results from the cement …

Freeze Thaw Durability Of Internally Cured Concrete Made Using Superabsorbent Polymers, Wesley A. Jones, W. Jason Weiss

International Conference on Durability of Concrete Structures

The use of superabsorbent polymers (SAPs) to produce internally cured concrete has been shown to be effective in reducing the potential for restrained shrinkage cracking of high performance concrete mixtures. However, not much is known regarding the freeze–thaw durability of concrete mixtures that incorporate SAPs for internal curing (IC). When SAP particles desorb (or partially desorb) the “water” (pore fluid) they contain for the purposes of IC, some believe that the void space created by these particles can provide enough empty voids to accommodate the additional volume caused by water expansion upon freezing. This paper investigates the freeze–thaw durability of …

Co2 Sequestration In Cement-Based Materials During Mixing Process Using Carbonated Water And Gaseous Co2, Jacek Kwasny, P. A. Muhammed Basheer, Mark I. Russell, William Doherty, Kieran Owens, Neil Ward

International Conference on Durability of Concrete Structures

This paper presents selected findings from a recently completed research project, aimed at the investigation of CO₂ sequestration in cement-based materials during the early stages of hydration when the cement paste is being mixed. Portland cement pastes were carbonated during the mixing process, using both carbonated water and gaseous CO₂, and their properties were compared to the control non-carbonated mix. All mixes were prepared in a purpose-designed chamber that permitted carbonated water and gaseous CO₂ to be mixed with the cementbased materials during the mixing process, without losses of CO₂ to the external environment. Temperature …

Mode I Fracture Toughness Of Eight-Harness-Satin Carbon Cloth Weaves For Co-Cured And Post-Bonded Laminates, Josh E. Smith

Master's Theses

Mode I interlaminar fracture of 3k 8-Harness-Satin Carbon cloth, with identical fill and weft yarns, pre-impregnated with Newport 307 resin was investigated through the DCB test (ASTM D5528). Crack propagations along both the fill and weft yarns were considered for both post-bonded (co-bonded) and co-cured laminates. A patent-pending delamination insertion method was compared to the standard Teflon film option to assess its applicability to mode I fracture testing. The Modified Beam Theory, Compliance Calibration method, and Modified Compliance Calibration method were used for comparative purposes for these investigations and to evaluate the validity of the proposed Equivalent Stiffness (EQS) method. …

Compression Testing And Failure Modes Of Steel-Concrete Composite (Sc) Structures For Nuclear Containment, Patrick Michael Wanamaker, Amit H. Varma

The Summer Undergraduate Research Fellowship (SURF) Symposium

Although being able to provide much cleaner power than burning coal and other fossil fuels, nuclear power plants are still a tough sell to the general public due to their history of being spontaneously dangerous. The containment structures surrounding these nuclear plants, however, can play a huge role in reducing the risks associated with them. Relatively new designs for these containment assemblies, known as SC (steel-concrete composite) structures, aim to increase the strength and durability of the containment facilities while keeping costs down. By varying the spacing between shear studs, the ratio of concrete to steel, and the ratio of …

Structural Reliability Analysis Of Corroded Steel Girder Bridge, Mohammed Shaalan Al Badran

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The natural aging, environmental impact, and appropriate design are certainly playing a serious role in safety of the bridges function. The functional safety of bridge constitutes a prime element of the transportation system serving commuters, passengers and freight. According to Federal Highway Administration, the steel bridges share represents a large amount of the United States’ bridges. In last century, the collapse of both the Silver Bridge at Point Pleasant, West Virginia over the Ohio River on December 15, 1967 and over the Mianus River Bridge in Connecticut on June 28, 1983 showed that steel corrosion has been the leading reason …

Fatigue Testing And Data Analysis Of Welded Steel Cruciform Joints, Alina Shrestha

LSU New Orleans Theses and Dissertations

In this study, ABS Publication 115, “Guidance on Fatigue Assessment of Offshore Structures” is briefly reviewed. Emphasis is on the S-N curves based fatigue assessment approach of non-tubular joints, and both size and environment effects are also considered. Further, fatigue tests are performed to study the fatigue strength of load-carrying and non-load-carrying steel cruciform joints that represent typical joint types in marine structures. The experimental results are then compared against ABS fatigue assessment methods, based on nominal stress approach, which demonstrates a need for better fatigue evaluation parameter. A good fatigue parameter by definition should be consistent and should correlate …

Creep, Fatigue And Creep-Fatigue Interactions In Modified 9% Cr - 1% Mo (P91) Steels, Valliappa Kalyanasundaram

Graduate Theses and Dissertations

Grade P91 steel, from the class of advanced high-chrome ferritic steels, is one of the preferred materials for many elevated temperature structural components. Creep-fatigue (C-F) interactions, along with oxidation, can accelerate the kinetics of damage accumulation and consequently reduce such components' life. Hence, reliable C-F test data is required for meticulous consideration of C-F interactions and oxidation, which in turn is vital for sound design practices. It is also imperative to develop analytical constitutive models that can simulate and predict material response under various long-term in-service conditions using experimental data from short-term laboratory experiments. Consequently, the major objectives of the …