Engineering Commons^™

Effect Of Fly Ash Fortification In The Manufacture Process Of Making Concrete Towards Characteristics Of Concrete In Sulfuric Acid Solution, Asep Handaya Saputra, Muhammad Shohibi, Masatoshi Kubouchi

Makara Journal of Technology

Fly ash is a silica or alumino silica material that can be used as a constituent of cement in the concrete manufacturing process. Utilization of fly ash aims to improve durability and minimize the reduction of concrete’s compressive strength exposed to an acidic environment, which can be achieved through the pozzolanic reaction of fly ash with Ca(OH)2 within concrete. The reduced content of Ca(OH)2 through pozzolanic reaction will minimize the tendency of ettringite formation (compounds that cause deterioration and decrease the compressive strength of concrete). In order to determine the relation between fly ash replenishment into concrete with concrete’s characteristics …

Study Of Structural Performance And Durability Of Concrete By Partial Replacement Of Cement With Hypo Sludge (Paper Waste), K Hari Kishan, N .Vidyasagar Lal,, 3 Sateesh Konni

Innovative Research Publications IRP India

Utilization of industrial waste products as supplementary cementitious materials (SCM) in concrete making is very important aspect in view of economical, environmental and technical reasons. As these supplementary cementitious materials have different chemical and mineralogical composition, their effect on micro structural properties and strength performance vary considerably. While producing paper, various wastes come out from the various processes in paper industries. The preliminary waste from paper industry is named as hypo sludge. In this study the material obtained from the paper industry waste (hypo sludge) is admixed with Portland cement at different replacement levels. The properties of concrete investigated include …

Investigation Into Mechanisms And Mitigation Of Alkali-Silica Reaction In Sustainable Portland Cement Concrete Containing Recycled Glass Materials, Kaveh Afshinnia

All Dissertations

A significant portion of recycled glass from municipal waste streams is not found to be suitable for reuse as cullet in the production of new glass containers, and as a result it is disposed in landfills. One of the appropriate ways to reduce the disposal of waste glass in landfills is by using it in portland cement concrete as an aggregate material and/or supplementary cementitious material to replace portion of portland cement. The high silica content of the soda glass (approximately 70%) can potentially behave as a pozzolanic material when finely ground, which may enhance the mechanical and durability properties …

Phase I Evaluation Of Selected Concrete Material Models In Ls-Dyna, Bradley J. Winkelbauer

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

Numerous roadside safety systems are configured with reinforced concrete materials, such as bridge railings, median barriers, and roadside parapets. These protective barrier systems are intended to safely contain and redirect errant vehicles as well as prevent impacts into hazardous fixed objects or other geometric features. The analysis and design of these structures may involve impact simulation with finite element software, like LS-DYNA, which includes multiple concrete material models. For such investigations, limited guidance is available for selecting preferred concrete material models and determining appropriate values for specific parameters. This Phase I study investigated the viability and performance of existing concrete …

Alkali-~Activated Fly Ash Binders: Feasibility As A Sustainable Alternative To Ordinary Portland Cement For Pre-~Cast Systems, Kimberly Sierra

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fresh, load-dependent, transport, and durability properties of alkali-activated fly ash mortars were studied. The influences of activator concentration, solution-to-binder ratio, curing condition, activator type, and sodium silicate-to-total solution ratio on the properties of the studied alkali-activated mortars were examined. This study was divided in two phases. The first phase dealt with the use of sodium hydroxide as the sole activator. The second phase of the study was divided into two parts, both of which used a combination of sodium hydroxide and sodium silicate as the activator solution. Part I of phase II used elevated temperature curing conditions, whereas part II …

Innovative Modular High Performance Lightweight Decks For Accelerated Bridge Construction, Sahar Ghasemi

FIU Electronic Theses and Dissertations

At an average age of 42 years, 10% of the nation’s over 607,000 bridges are posted for load restrictions, with an additional 15% considered structurally deficient or functionally obsolete. While there are major concerns with decks in 75% of structurally deficient bridges, often weight and geometry of the deck further limit the load rating and functionality of the bridge. Traditional deck systems and construction methods usually lead to prolonged periods of traffic delays, limiting options for transportation agencies to replace or widen a bridge, especially in urban areas.

The purpose of this study was to develop a new generation of …

Reducing The Porosity And Sealing Cracks By Using Crystalline Admixture In Conventional Concrete, Visar Krelani, Liberato Ferrara

UBT International Conference

There is a continuous increase of quality on civil engineering materials in developed countries and parallel increase of need for new constructions in developing countries. Professional community should propose solutions for the durability that can resist in different severe environments. The most important factor that can affect concrete durability is represented by the pore distribution. Transport properties can take place through the porous network inside the cementitious composites and the aggregates interface, permitting the ingress of aggressive agents damaging concrete function intrinsically as a material and the well-functioning of the entire structure. The use of a crystalline admixture during the …

Feasibility Of Cathodic Protection In Grouted Post Tensioned Tendons - Exploratory Model Calculations, Jacob Dharma Bumgardner

USF Tampa Graduate Theses and Dissertations

Recent corrosion related failures of grouted post tensioned tendons, even after the introduction of improved grouts, have led to renewed interest in supplemental or backup means of corrosion control for these systems. A finite element model is presented to explore feasibility of impressed current cathodic protection of strand in grouted tendons. The model examines polarization evolution as function of service time and includes consideration of anode placement and size, grout porosity, pore water alkalinity, electrochemical species diffusivity and applied voltage on the polarization efficacy and durability of such a system. The exploratory model projections suggested that, within the context of …

Shear Strengthening Of Reinforced Concrete Beams Using Textile-Reinforced Mortar, Oluwafunmilayo Morenike Awani

Theses

The effectiveness of using carbon textile-reinforced mortar as an innovative technique to improve the shear response of reinforced concrete beams has been investigated. The research comprised double-shear bond testing on bond behavior of textile-reinforced mortar, large-scale beam testing on shear response of reinforced concrete beams strengthened with textile-reinforced mortar, and nonlinear finite element modeling of the tested beam specimens. Test variables of the double-shear bond testing were the matrix type, and width/length of the bonded area, whereas for the large-scale beam testing, the variables included the number of textile-reinforced mortar layers, matrix type, and amount of internal stirrups. Results of …

Analytical Model Of Ultrasonic Pulse Velocity Of Waste Lcd Glass Concrete, Chien-Chih Wang, Her-Yung Wang, Shyh-Haur Chen, Chi Huang

Journal of Marine Science and Technology

The purpose of this study is to establish a prediction model for the ultrasonic pulse velocity (UPV) of waste LCD glass concrete and then analyze the results obtained from a series of laboratory tests. The power function is used to perform the nonlinear-multivariate regression analysis of the UPV prediction model, with parameters such as water-binder ratio (w/b), curing age (t) and waste glass content (G). According to the relative regression analysis, the UPV prediction model is developed. The calculated results are in accord with the laboratory-measured data, which are the concrete UPV of various mix proportions. The regression analysis results …

The Performance And Service Life Prediction Of High Performance Concrete In Sulfate And Acidic Environments, Shuo Zhang

FIU Electronic Theses and Dissertations

Concrete substructures are often subjected to environmental deterioration, such as sulfate and acid attack, which leads to severe damage and causes structure degradation or even failure. In order to improve the durability of concrete, the High Performance Concrete (HPC) has become widely used by partially replacing cement with pozzolanic materials. However, HPC degradation mechanisms in sulfate and acidic environments are not completely understood. It is therefore important to evaluate the performance of the HPC in such conditions and predict concrete service life by establishing degradation models.

This study began with a review of available environmental data in the State of …

Evaluation Of Deterioration Of Structural Concrete Due To Chloride Intrusion And Other Damaging Mechanisms, Sudhir Palle, Brian K. Howell, Theodore Hopwood Ii, Bobby W. Meade

Kentucky Transportation Center Research Report

Kentucky's bridges continue to age and experience distress. The intrusion of chlorides into concrete remains the primary mechanism for deterioration. It leads to reinforcing steel corrosion that damages the adjoining concrete structure. This study found problematic chloride concentrations in Kentucky concrete bridge elements (decks, pier caps, abutments). Chloride levels have been found at concentrations sufficient to initiate reinforcing steel corrosion. In some cases, chloride concentrations were sufficient to cause accelerated corrosion and produce major section loss of reinforcing steel. Advanced stages of corrosion such as these typically require costly repairs and maintenance to extend the service life of bridges.

Field …

Extrinsic Influence Of Environment On The Corrosion Behaviour Of Enamel-Coated Steel Dowel Bars, Srikanth Bajaj, Anil Patnaik, Joe Payer, Robert Liang, Kannan Manigandan, Tirumalai Srivatsan

Anil Patnaik

A new type of enamel coated dowel bars for use as concrete pavements has been recently developed and implemented. A gradual deterioration of such bars can occur due to corrosion occurring at locations of the fine microscopic cracks and other defects in the coating. The results of a study aimed at evaluating and understanding the corrosion resistance of such dowel bars is presented and comparisons made with corresponding epoxy-coated dowel bars. Identical defects were introduced onto the surface of the dowel bars with the two types of coatings. The extrinsic influence of environment and resultant corrosion based on type, location …

Extrinsic Influence Of Environment On The Corrosion Behaviour Of Enamel-Coated Steel Dowel Bars, Srikanth Bajaj, Anil Patnaik, Joe Payer, Robert Liang, Kannan Manigandan, Tirumalai Srivatsan

Robert Y. Liang

A new type of enamel coated dowel bars for use as concrete pavements has been recently developed and implemented. A gradual deterioration of such bars can occur due to corrosion occurring at locations of the fine microscopic cracks and other defects in the coating. The results of a study aimed at evaluating and understanding the corrosion resistance of such dowel bars is presented and comparisons made with corresponding epoxy-coated dowel bars. Identical defects were introduced onto the surface of the dowel bars with the two types of coatings. The extrinsic influence of environment and resultant corrosion based on type, location …

Post-Tensioned Concrete Shear Wall, Purdue Ect Team

ECT Fact Sheets

The post-tension concrete shear wall by Tipping Mar will replace the conventional concrete shear wall in earthquake prone areas in many instances, depending on the height and scale of the building.

Effect Of Mortar Coating On Concrete Carbonation, Wen-Hu Tsao, Ming-Te Liang, Jiang-Jhy Chang, Nai-Ming Huang

Journal of Marine Science and Technology

The mechanism of the effect of mortar coating on carbonation of concrete is investigated. Theoretical methods of Fick's first and second laws of linear diffusion are used to calculate the carbonation depth of concrete without and with mortar coating, respectively. Theoretical analyses are also done to obtain the carbonation retard coefficients of mortar coating on concrete with surface coatings. A great deal of well organized experimental tests are carried out to verify the values of calculation. The results of present study indicate that the suitable mortar coating on concrete can effectively delay carbonation of concrete. The carbonation depth is inversely …

Bonded Anchors In Concrete Under Sustained Loading, Douglas Droesch

Masters Theses

Post installed anchors come in either mechanical anchors that develop their strength purely through mechanical interlock with the base concrete, or bonded anchors that develop their strength by bonding anchor rod to the base concrete. Bonded anchors are either grouted, typically cementitious material, or adhesive, typically a chemical material. This thesis presents a current literature review of post-installed bonded anchors, preliminary testing of adhesive bonded anchors, and details of short term and long term test setups for future testing. The purpose of this thesis was to develop the test setups that will be used for future testing on anchors.

Measurement Of Transfer And Development Lengths Of 0.7 In. Strands On Pretensioned Concrete Elements, Canh Ngoc Dang

Graduate Theses and Dissertations

The implementation of 0.7 in. (17.8 mm), Grade 270 (1860), low-relaxation prestressing strands in construction is slow regardless of its advantages over the use of 0.6 in. (15.2 mm) and 0.5 in. (12.7 mm) strands. The limited research data and unavailable design guidelines partially account for the slow utilization. This study measured transfer and development length, and evaluated applicable strand spacing of 0.7 in. (17.8 mm) prestressing strands for 24 pretensioned concrete beams. Each beam contained one prestressing strand or two prestressing strands placed at spacing of 2.0 in. (51 mm). The beams were fabricated with high strength, conventional concrete …

Design And Construction Of A Full-Scale Lateral Impact Testing Facility, Cody Aaron Mitchell

Masters Theses

The goal of this work is to design and construct a full scale lateral impact testing facility that is capable of recreating the damage that would be created by an overheight vehicle collision. This was accomplished by impacting a test specimen with an 8000 lbs. impact cart. The impact cart is raised on an elevated track and allowed to roll down the track with a change in height of 10 ft. This change in height is what provides the impact force necessary to recreate an overheight vehicle collision. The track is constructed out of wood and is designed to withstand …

Blind Source Separation For Feature Detection And Segmentation In Ground Penetrating Radar (Gpr) Lmaging Of Concrete Bridge Decks For Nondestructive Condition Assessment, Vincent Krause

Dissertations

Concrete bridge decks require periodic condition assessment and preventive maintenance to extend their useful lifespan. Nondestructive evaluation methods such as Ground Penetrating Radar (GPR) are slowly beginning to replace or complement the manual (visual) assessment of bridge conditions for detecting defects at their early stages. However, GPR scans of bridge decks are frequently cluttered with high amplitude reflections from known parts of the bridge deck, which make the detection of defects’ low amplitude reflections difficult. One such known part is the embedded steel reinforcement bars known as rebar.

This dissertation presents a novel approach to the automated detection of defects …

Experimental And Numerical Study On Full-Scale Precast Steel Fibre-Reinforced Concrete Pipes, Nedal Mohamed

Electronic Thesis and Dissertation Repository

Reinforced concrete (RC) pipes are widely used as open channels (non-pressurized pipes) for sewage and storm water conveyance. RC pipes have generally achieved a reliable long-term performance. Depending on multiple parameters (e.g. pipe diameter, pipe wall thickness, required strength, etc.) the pipe may have up to three welded reinforcement cages in order to resist anticipated loads. Each cage is an assembled unit of steel reinforcement consisting of circumferential and longitudinal bars or wires. The fabrication process of a steel cage reinforcement is time and labour consuming. Thus, eliminating the steel cage reinforcement will yield an overall reduction in the production …

Prediction Of Unconfined Compressive Strength Of Pulverized Fuel Ash-Cement-Sand Mixture

Faculty of Engineering University of Malaya

Recently, ground improvement has become much more feasible. Chemical stabilization is a quick and affordable approach to enhancing soil characteristics. An important avenue of research is discovering alternative materials for use in soil enhancement. Pulverized fuel ash (PFA), which is a waste byproduct of coal power plants, has been shown to reduce the environmental risks and costs involved in construction. In this study, a series of unconfined compressive tests were performed for various mixtures of cement, PFA, and sand; the tests considered both the curing period and the optimum moisture content (OMC). In addition, multiple variable linear regression was used …

Geopolymer Concrete-Filled Pultruded Composite Beams – Concrete Mix Design And Application, Wahid Ferdous, Allan Manalo, Amar Khennane, Obada Kayali

Wahid Ferdous

The limited research on the geopolymer concrete mix design for targeting a specific strength is identified an obstacle for their effective design and wide use. In this paper, a mix design procedure has been proposed for fly-ash based geopolymer concrete and its use as infill hybrid composite beam is investigated. Then, the structural performance of geopolymer concrete filled hybrid composite beam is investigated to determine their possible application in civil infrastructure. Firstly, a detailed procedure of mix design for fly-ash based geopolymer concrete is presented. Secondly, three hybrid beams filled with geopolymer concrete were prepared and tested in a four-point …

Stiffness Performance Of Polyethylene Terephthalate Modified Asphalt Mixtures Estimation Using Support Vector Machine-Firefly Algorithm

Faculty of Engineering University of Malaya

Predicting asphalt pavement performance is an important matter which can save cost and energy. To ensure an accurate estimation of performance of the mixtures, new soft computing techniques can be used. In this study, in order to estimate the stiffness property of Polyethylene Terephthalate (PET) modified asphalt mixture, different soft computing methods were developed, namely: support vector machine-firefly algorithm (SVM-FFA), genetic programming (GP), artificial neural network (ANN) and support vector machine. The support vector machine-firefly algorithm (SVM-FFA) is a metaheuristic search algorithm developed according to the socially dashing manners of fireflies in nature. To develop the models, experiments were performed. …

Supplementary Cementitious Materials Origin From Agricultural Wastes - A Review

Faculty of Engineering University of Malaya

Concrete is heavily used as a construction material in modern society. With the growth in urbanization and industrialization, the demand for concrete is increasing day by-days. Therefore, raw materials and natural resources are required in large quantities for concrete production worldwide. At the same time, a considerable quantity of agricultural waste and other types of solid material disposal are posing serious environmental issues. To minimize and reduce the negative impact of the concrete industry through the explosive usage of raw materials, the use of agricultural wastes as supplementary cementitious materials, the source of which are both reliable and suitable for …

Numerical Simulation Of Prestressed Precast Concrete Bridge Deck Panels Using Damage Plasticity Model, Wei Ren, Lesley Sneed, Yang Yang, Ruili He

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

The Role Of Shrinkage Strains Causing Early-Age Cracking In Cast-In-Place Concrete Bridge Decks, Tayyebeh Mohammadi, Baolin Wan, Christopher M. Foley

Civil and Environmental Engineering Faculty Research and Publications

Early-age cracking in cast-in-place reinforced concrete bridge decks is occurring more frequently now than three decades ago and principle factors that lead to early-age deck cracking are not fully understood. A finite element (FE) simulation methodology for assessing the role of shrinkage-induced strains in generating early-age bridge deck cracking is described. The simulations conducted indicate that drying shrinkage appears to be capable of causing transverse (and possibly longitudinal) bridge deck cracks as early as 9 to II days after bridge deck placement. The drying-shrinkage induced stresses would result in transverse cracking over interior pier supports in a typical bridge superstructure …

Utilisation Of Iron Ore Tailings As Aggregates In Concrete, Francis Atta Kuranchie, Sanjay Kumar Shukla, Daryoush Habibi, Alireza Mohyeddin

Research outputs 2014 to 2021

Sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. This study seeks to add value to the tailings by utilising them as a replacement for aggregates in concrete. A concrete mix of grade 40 MPa was prepared in the laboratory with water–cement ratio of 0.5. The concrete were cured for 1, 2, 3, 7, 14 and 28 days. The properties of the concrete such as workability, durability, density, compressive strength and indirect tensile strength were tested. A controlled mix of concrete was also prepared in similar way using conventional materials …

Advanced Sustainable Concrete Materials For Infrastructure Applications, Kaylea Ann Smith

Masters Theses

"This study was performed to examine the effects of cement replaced by high volumes of Class C fly-ash on durability characteristics of concrete up to 120 days. Specifically, this study investigates possibility of amending American Society for Testing and Materials (ASTM) to allow High Volume Fly-ash (HVFA) concrete to cure until later ages prior to testing instead of 28 days. Five mix designs were compared with varying fly-ash percentages from 0 to 70% (by total cementitious mass). No other additives were present in any of the five mix designs. Water-to-cementitious ratio (w/cm) and total cementitious material remained constant as 0.40 …

Characterisation And Applications Of Iron Ore Tailings In Building And Construction Projects, Francis Atta Kuranchie

Theses: Doctorates and Masters

The mine tailings are generated as the wastes worldwide as a result of exploration, excavation, blasting, beneficiation and extraction of mineral ores. In Western Australia, due to the extensive mining activities and increasing low grade ores, there is generation of mine tailings in large quantities, which could lead to environmental and disposal problems. The common practice of handling the tailings are to store them in tailing dams or as stockpiles near mine sites. Limited quantities are sometimes used as backfills and other applications. The utilisation of tailings in building and construction projects, which may consume a large volume of wastes, …