Engineering Commons^™

Characteristics Of Thick Concrete Neutron Reflection, Richard Gordon Taylor

Doctoral Dissertations

Water is considered as a neutron reflector in nuclear criticality safety evaluations because it is readily available and easily forms a close-fitting shape around fissile material. Concrete is commonly encountered industrial environments and can be a more effective reflector than water. Nuclear criticality safety literature reporting experimental and analytical studies involving concrete as a reflector from the 1950’s to the present was reviewed. Nuclear criticality safety community perspective on concrete reflection has evolved from acknowledgement that concrete is a reflector through recognition that concrete can be a more effective reflector than water to current interest in identifying which constituents are …

Identifying Damage, Predicting Expansion, And Determining The Effectiveness Of Sealers On Concrete Affected By Alkali-Silica Reaction And Freeze-Thaw, Matthew Caleb Waidner

Graduate Theses and Dissertations

Premature cracking of the barrier wall and pavement on I-49 south of Fayetteville, Arkansas due to a combination of Alkali-Silica Reaction (ASR) and freeze-thaw has led to ASR and freeze-thaw research at the University of Arkansas. Potential for further expansion (PFET), Damage Rating Index (DRI), and mitigation of freeze-thaw and ASR with sealers testing and results are contained herein. PFET results indicated that the pavement will not continue to expand from ASR. With other interstate pavements deteriorating prematurely throughout Arkansas, DRI has shown that most are damaged not only by ASR but by freeze-thaw too. Recommendations for freeze-thaw’s inclusion into …

Feasibility Study Of Using Recyclable Polyethylene (Pet) Materials As Coarse Aggregate For Concrete Mixtures, Philip M. Angelo

Construction Management

The feasibility of using recyclable household plastics, specifically those made of polyethylene, commonly used in water and soda bottles, as a replacement for concrete coarse aggregate, was assessed. A method was developed for cutting polyethylene materials into fibrous strips. These strips were then used as a replacement for the rock coarse aggregate in batches of concrete. Standard 6” x 12” test cylinders were made using the concrete mixture and subject to destructive compressive testing in order to yield the compressive strength of the concrete mix 7, 14, 21, and 28 days after pouring. Three mixtures were tested, one control with …

Reflectivity Of Light Emitting Diodes (Led) And Incandescent Lights On Concrete And Asphalt Pavements., Jeremy Elliott Rice

Electronic Theses and Dissertations

The purpose of this study is to investigate the reflectivity of light on concrete and asphalt pavement systems. In 1983, the Illuminating Engineering Society (IES) published the first recommended practice (RP-8) for the design of roadway and parking lot lighting. This design method implemented empirically tested factors which were defined as the “reduced luminance coefficients” or the R-Tables. The R-Tables are essential for proper design of light pole installation dimensions, required power, and the distribution of light. The originally tested pavements are not necessarily representative of modern pavement materials used today. Moreover, recent Light Emitting Diodes (LED) are a relatively …

Continuous Long-Term Health Monitoring Using Ultrasonic Wave Propagation, Ece Erdogmus

Nebraska Department of Transportation: Research Reports

No abstract provided.

Performance Of Continuous Concrete Slabs Reinforced With Hybrid Steel-Basalt Bars, Mohammad Sohayeb Akiel

Theses

Continuous steel-reinforced concrete structures are vulnerable to corrosion

Damage when exposed to harsh environment. Although replacing conventional steel entirely with basalt fiber-reinforced polymer (BFRP) bars can eliminate corrosion problems, the lower modulus of elasticity of BFRP would reduce serviceability of the structure. The use of hybrid steel-BFRP bars rather than BFRP bars only has a potential to improve the serviceability of continuous concrete

Structures without reducing the deformation capacity. Through experimental testing and numerical simulation, this work aims to examine the structural behavior of two-span concrete specimens internally reinforced with BFRP or hybrid steel-BFRP bars.

A total of 12 two-span …

Prediction Of Punching Shear Capacity Of Two-Ways Frp Reinforced Concrete Slabs, Ilker Fatih Kara, Besian Sinani

UBT International Conference

An innovative solution to the corrosion problem is the use of fiber-reinforced polymer (FRP) as an alternative reinforcing material in concrete structures. In addition to the non corrodible nature of FRP materials, they also have a high strength-to-weight ratio that makes them attractive as reinforcement for concrete structures. Extensive research programs have been carried out to investigate the flexural behavior of concrete members reinforced with FRP reinforcement. On the other hand, the shear behavior of concrete members, especially punching shear of two-way slabs, reinforced with FRP bars has not yet been fully explored. The existing provisions for punching of slabs …

Development Of A Transition Between An Energy-Absorbing Concrete Barrier And A Rigid Concrete Butress, Tyler L. Schmidt, Ronald K. Faller, Jennifer D. Schmidt, John D. Reid, Robert W. Bielenberg, Scott Rosenbaugh

Nebraska Department of Transportation: Research Reports

From 2010 to 2015, MwRSF researchers developed the RESTORE barrier, which is a restorable MASH TL-4 median barrier with a steel and concrete rail supported by elastomer posts and steel skids. The research effort reported herein describes the initial development of a transition from the RESTORE barrier to a rigid TL-4 concrete buttress.

The previously-developed RESTORE barrier LS-DYNA model was validated against three full-scale vehicle crash tests. Several design concepts were generated through a series of brainstorming efforts. The primary transition concept consisted of a pin and loop connection between the RESTORE barrier and rigid concrete buttress, which was designed …

Chloride-Binding Isotherms In Concrete Submitted To Non-Steady-State Diffusion-Migration Model, Wen-Hu Tsao, Ming-Te Liang, Ta-Peng Chang

Journal of Marine Science and Technology

We propose a mathematical non-steady-state, time/depth dependent diffusion-migration model based on the modified Fick’s second law of diffusion. It considers the effects of different chloride binding mechanisms for the transport process of chloride ions diffused in a porous concrete on the variation of its chloride profile. Four different chloride-binding isotherms, i.e., no binding, linear binding, Langmuir binding and Freundlich binding, together with the time/depth dependent chloride diffusivities are investigated. Results of this study show that the variations of amounts of available free chloride ions in the solution of saturated concrete resulting from different chloride-binding isotherms have significant effects on the …

Bridge Deck Research At The University Of Tennessee: A Summary Thesis, Lindsey Brooke Phelps

Masters Theses

Currently, there has been no compilation of all the research the University of Tennessee has completed on chloride ion penetration in concrete bridge decks. The following thesis is a brief summary of the work that has been completed under Dr. Edwin Burdette’s direction over the last six years along with some additional literature review. The testing consisted of Surface Resistivity and Rapid Chloride Ion Penetration testing. This testing showed that there is, in fact a correlation between the two test methods, though SR testing is much easier to conduct. Considerable testing was completed on bridge decks throughout the state of …

Effect Of Severe Corrosion On Lateral Strength Of Square Rc Bridge Columns, Sara Sotoud

Dissertations - ALL

Corrosion of reinforcing steel bars is the primary durability problem that causes degradation of reinforced concrete structures located in aggressive environments. Severe corrosion of steel bars decreases the lateral load-carrying capacity of reinforced concrete members, causes loss in the mechanical properties of reinforcement and cross-sectional area of steel bars and concrete cover, bond deterioration, reduces anchorage of steel bars, and decreases the confinement by transverse reinforcement. Consequently, corrosion results in drop in the lateral strength of columns. Therefore, studying response of corroded reinforced concrete columns subjected to lateral loads is necessary.

According to the Federal Highway Administration (FHWA) report in …

Standardized Testing Of Non-Standard Photovoltaic Pavement Surfaces, John H. Nussbaum, Robert A. Lake, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

Emerging photovoltaic products have expanded the applications for the technologies into markets previously unconsidered for what was thought to be a delicate electronic product. One company leading this effort, Solar Roadways, Incorporated, is producing pavement replacing photovoltaic systems and proposing their use in everything from sidewalks to runways. Current pavement testing methods cannot be applied to these non-homogenous structures to identify if they can support the required loads. However, the standards called out specifically for pavements may be able to be translated to these products and their non-homogenous structures and non-standard materials to identify if they are able to perform …

Use Of Recycled Crushed Concrete (Rcc) Fines For Potential Soil Stabilization, Lindeman Mark, Varilek Brandon, Lieska Halsey, Rick Gloe, Maria Olomi

Nebraska Department of Transportation: Research Reports

This study evaluated the use of Recycled Crushed Concrete (RCC) Fines for potential soil stabilization. Soil stabilization is the enhancement of subgrade stability to improve the constructability of successive pavement layers. Use of RCC fines may not only provide less costly alternatives for subgrade stabilization, but their use may also alleviate landfill disposal challenges.

Edge Detection Of Concrete Mesostructure Based On Dis Operator, Bin Feng, Zicheng Xu, Jin Xia, Shijie Jin, Weiliang Jin

International Conference on Durability of Concrete Structures

Aggregate edge detection is the basis of creating concrete mesoscale model, which is applied to analyze concrete mesoscale characteristics. A concrete digital image edge detection method using DIS operator is presented in this paper. Mean filter, multi-scale filter, and Gaussian filter are compared on the effect of concrete image noise reduction. Based on the result, Gaussian filter is the most optimum method to reduce image noise and remain aggregate edge distinct. Sobel operator, Laplacian operator, and DIS operator are applied respectively to detect the aggregate edge on Gaussian filter processed images. Based on the experiment, DIS operator outperforms other two …

Aggregate Shape Effect On Multicomponent Ionic Electromigration In Concrete, Qing-Feng Liu, Long-Yuan Li, Jian Yang

International Conference on Durability of Concrete Structures

This paper presents a numerical study on the mechanism of chloride migration in concrete. Unlike most of existing work, this study utilises multicomponent ionic transport models to reflect the influence of ionic interactions by coupling both mass conservation and Poisson’s equations. A series of 2-D, 3-phase models with different shapes and volume fractions of aggregates are developed to simulate the chloride migration test. Through a comparatively overall numerical exploration that considers external voltage, ionic interactions, heterogeneous nature, ITZ, and ionic binding, some important features about multispecies coupling and aggregate shape effect, which have not been properly reported from existing concrete …

Seismic Design Of A Prestressed Concrete Bridge, Alperen Ozel

University of New Orleans Theses and Dissertations

Latest advancements in software have become an indispensable tool in structural analysis. The main goal of this thesis is to examine dynamic responses of bridges in seismic activity with the help of such tool as CSi Bridge. Therefore, throughout this study, a prestressed concrete bridge model will be thoroughly designed. In the first section, the required materials and structural components will be introduced. The following section will cover calculations required for modeling. The actual modeling of the structure will be carried out in Section 3. In Section 4, the set of required analysis for seismic design such as modal, pushover …

A Concrete Water Pasteurization Device For Third World Countries, Andrea R. Murchie

Senior Honors Projects, 2010-2019

In the rural areas of South Africa, as well as many other developing countries, people cook food and sterilize their water by heating over open fires. Many times the fires are inside of homes, which more often than not are very small. Children will often be the ones to tend to the fire, out of necessity while parents and other family members are tending to other work and needs.

The purpose of my Senior Honors Project was to design a concrete vessel that can hold water and heat the water to pasteurization (149°F) when exposed to sunlight for an extended …

Impact Of Extreme Summer Temperatures On Bridge Structures, Ryan Hagedorn

Graduate Theses and Dissertations

Climate change and its effect on weather in the United States is a well-documented phenomenon. In particular, extreme heat waves have become more intense, more frequent, and longer lasting, especially in the southern United States. As with much of America’s transportation infrastructure, prestressed concrete bridge girders experience the effects of these heat waves. Uneven heating of optimized bridge girder sections results in large non-linear temperature gradients. In this study, temperature was monitored in three different AASHTO I-girders to determine the vertical and transverse temperature gradients in a pre-deck placement condition. It was determined that the current design standard, which uses …

Quantification And Characterization Of Fracture Resistance In Asphalt Concrete Based On R-Curve Method, Shu Yang

Graduate Theses and Dissertations

The application of fracture energy is widely applied in the evaluation of cracking in the laboratory for asphalt concrete. However, this single number does not provide information on the characterization of the initiation and propagation of cracks. The Resistance Curve method, or R-Curve, is widely applied in characterizing various materials including, but not limited to, metal, polymer, rock, and composite. This research R-Curve method introduces asphalt concrete through a stepwise approach. First, in chapter one, there is a literature review of the history of fracture mechanics, fracture research in asphalt concrete, and an examination of the role of R-Curve application …

Carbonation Resistance Of Concrete With Mortar Coating, Wen-Hu Tsao, Ming-Te Liang, Nai-Ming Huang, Ke-Hung Liao

Journal of Marine Science and Technology

The principal purpose of this paper was theoretically to study the carbonation resistance of a semi-infinite medium which concrete has a mortar coating having diffusion properties different from those of the rest of the medium. The analytical solution of a semi-infinite composite medium was used to predict the time required for subsidence due to concrete with mortar coating. The inaccurate analytical solution was published in previous books. Thus, the analytical solution of a semi-infinite composite medium is re-derived in this article. The governing equations without initial and boundary conditions in the previous books are also pointed out. In order to …

Evaluation Of Penetration Depth And Protective Effectiveness Of Concrete-Penetrating Sealer Materials, Sung-Ching Chen, Ran Huang, Hui-Mi Hsu, Si-Yu Zou, Li-Wei Teng

Journal of Marine Science and Technology

Crystal penetrating sealer materials (PSMs) are commonly used on the surface of concrete to protect the surface from damage and thereby extend its service life. Such materials penetrate into existing pores or cracks and form crystals, which block potential paths through which unknown materials could enter and degrade the concrete. In this study, the constituent compounds of a PSM were divided into seven categories, labeled CAT I to CAT VII, and five discrete particle size fractions corresponding to sieve Nos. 30, 50, 100, 200, and 200 were considered. Energy dispersive spectrometry revealed that the constituent elements of the PSM were …

Corrosion Of Rebar Under Carbonation And Salt Environment, Wei-Chung Yeih, Jiang-Jhy Chang, Yu-Ping Huang, Ran Huang

Journal of Marine Science and Technology

In this study, the behavior of reinforced concrete under carbonation and in a salt environment was investigated. Three types of cements- Type I cement, Type II cement and highalumina cement (HAC) - were used to study the influence of cement on reinforced concrete behavior. To simulate chloridecontaminated concrete, 1% NaCl (by cement weight) was added to some groups of specimens. Results revealed that the carbonation released chloride ions from Friedel's salt, which increased the chloride content near the carbonation front. The carbonation rate of HAC concrete was higher than that of Type I and Type II cement concrete. The corrosion …

Normal-Strength And High-Strength Concrete Columns Under Cyclic Axial Load And Biaxial Moment, Mehdi Zarei

Dissertations

The technique of using Carbon Fiber Reinforced Polymer (CFRP) materials to repair and strengthen various concrete members has become popular in the structural retrofitting field as an effective way to enhance the strength and ductility of concrete members due to its superior mechanical properties. In this study a method was introduced to study the behavior of concrete columns with and without CFRP jackets under constant axial load and variable lateral load. The lateral load was applied monotonically and cyclically. To predict the behavior of concrete columns under monotonic and cyclic compressive loadings, a computer code was developed to produce the …

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 …

Axial And Flexural Behavior Of Unreinforced And Frp Bar Reinforced Circular Concrete Filled Frp Tube Columns, Muhammad N. S Hadi, Qasim Khan, M Neaz Sheikh

Faculty of Engineering and Information Sciences - Papers: Part A

Fiber Reinforced Polymer (FRP) composites have emerged as a viable alternative of steel reinforcement due to higher ultimate tensile strength to weight ratio and corrosion resistance of FRP composites. Concrete Filled Fiber Reinforced Polymer Tube (CFFT) technique for new column construction has attracted significant research attention. This paper investigated the axial and flexural behavior of concrete filled Carbon FRP (CFRP) tube columns with and without CFRP bar and concrete filled Glass FRP (GFRP) tube columns with and without GFRP bar. The test results of 16 circular CFFT and four steel Reinforced Concrete (RC) specimens of 203-205 mm diameter and 800-812 …

Experimental Investigation Of The Behaviour Of Concrete Beams Reinforced With Gfrp Bars Under Static And Impact Loading, Matthew Goldston, Alex M. Remennikov, M Neaz Sheikh

Faculty of Engineering and Information Sciences - Papers: Part A

Composite materials, including Fibre Reinforced Polymer (FRP) bars, have been gaining momentum as alternatives to traditional steel reinforcements in civil and structural engineering sectors. FRP materials are non-corrosive, non-conductive, and lightweight and possess high longitudinal tensile strength, which are advantageous for their use in civil infrastructure. This paper presents the results of an experimental investigation into the effects of the use of glass FRP (GFRP) bars as internal reinforcement on the behaviour of concrete beams. Both static and dynamic (impact) behaviours of the beam have been investigated. Twelve GFRP reinforced concrete (RC) beams were designed, cast and tested. Six GFRP …

Design-Oriented Stress–Strain Model For Concrete Under Combined Frp-Steel Confinement, G Lin, Tao Yu, Jin Guang Teng

Faculty of Engineering and Information Sciences - Papers: Part A

Extensive research has been conducted on fiber-reinforced polymer (FRP)-confined plain and RC columns, leading to a large number of stress–strain models. Most of these models have been developed for FRP-confined plain concrete and are thus applicable only to concrete in FRP-confined RC columns with a negligible amount of transverse steel reinforcement. The few models that have been developed for concrete under the combined confinement of FRP and transverse steel reinforcement are either inaccurate or too complex for direct use in design. This paper presents an accurate design-oriented stress–strain model for concrete under combined FRP-steel confinement in FRP-confined circular RC columns. …

Experimental Study On Frp Tube Reinforced Concrete Columns Under Different Loading Conditions, Weiqiang Wang, M Neaz Sheikh, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part A

The behavior of fiber-reinforced polymer (FRP) tube reinforced concrete (FTRC) columns under different loading conditions was investigated in this study. Four groups of 16 specimens were cast and tested. Specimens in the first group (the reference group) were re- inforced with longitudinal steel bars and steel helices (Group REF). Specimens in the second group were reinforced with intact glass FRP tubes (Group IT). Specimens in the third group were also reinforced with intact glass FRP tubes. In addition, polymer grid was embedded into the concrete cover to reduce the cover spalling (Group ITG). Specimens in the fourth group were reinforced …

Experimental Investigation Of Gfrp-Reinforced And Gfrp-Encased Square Concrete Specimens Under Axial And Eccentric Load, And Four-Point Bending Test, Muhammad N. S Hadi, Jim Youssef

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents the results of an experimental study on the axial and flexural behavior of square concrete members reinforced with glass fiber-reinforced polymer (GFRP) bars and embedded with pultruded GFRP structural sections under different loading conditions. The main parameters investigated in this study were the influence of the type of internal reinforcement (steel bars, GFRP bars and pultruded GFRP structural I-sections and C-sections) and magnitude of load eccentricity on the flexural and compressive behavior of square concrete members. To fulfil the objectives of this study, 16 reinforced concrete specimens were tested, of which 12 were tested as columns under …

Structural Behaviours Of Railway Prestressed Concrete Sleepers (Crossties) With Hole And Web Openings, Sakdirat Kaewunruen, Erosha Kahawatta Gamage, Alex M. Remennikov

Faculty of Engineering and Information Sciences - Papers: Part A

As the crosstie beam in railway track systems, the prestressed concrete sleepers (or railroad ties) are principally designed in order to carry wheel loads from the rails to the ground. Their design takes into account static and dynamic loading conditions. It is evident that prestressed concrete has played a significant role as to maintain the high endurance of the sleepers under low to moderate repeated impact loads. In spite of the most common use of the prestressed concrete sleepers in railway tracks, there have always been considerable demands from rail and track engineers to improve serviceability and functionality of concrete …