Engineering Commons^™

Integration Of A Prototype Wireless Communication System With Micro-Electromechanical Temperature And Humidity Sensor For Concrete Pavement Health Monitoring, Shuo Yang, Keyan Shen, Halil Ceylan, Sunghwan Kim, Daji Qiao, Kasthurirangan Gopalakrishnan

Daji Qiao

In recent years, structural health monitoring and management (SHMM) has become a popular approach and is considered essential for achieving well-performing, long-lasting, sustainable transportation infrastructure systems. Key requirements in ideal SHMM of road infrastructure include long-term, continuous, and real-time monitoring of pavement response and performance under various pavement geometry-materials-loading configurations and environmental conditions. With advancements in wireless technologies, integration of wireless communications into sensing device is considered an alternate and superior solution to existing time- and labor-intensive wired sensing systems in meeting the requirements of an ideal SHMM. This study explored the development and integration of a wireless communications sub-system …

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 …

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. …

Evaluating Waste Concrete For The Treatment Of Acid Sulphate Soil Groundwater From Coastal Floodplains, Gyanendra Regmi, Buddhima Indraratna, Long Nghiem, Laura Banasiak

Laura J Banasiak Dr

The treatment of acidic groundwater generated from acid sulphate soil (ASS) terrain is a challenging environmental issue in coastal floodplains of Australia. In this study, a laboratory column experiment was conducted to assess the performance of waste concrete for treating the acidic groundwater leachate from ASS terrain of the Shoalhaven region of NSW. The groundwater was highly acidic (pH of 2.5–3.5) and contained elevated concentrations of iron (10–90 mg/L) and aluminium (30–45 mg/L). Passage of the acidic groundwater through the column filled with waste concrete resulted in a significant improvement in water quality. Reduction in the concentration of iron and …

Armouring By Precipitates And The Associated Reduction In Hydraulic Conductivity Of Recycled Concrete Aggregates Used In A Novel Prb For The Treatment Of Acidic Groundwater, Punyama Pathirage, Buddhima Indraratna, Long Nghiem, Laura Banasiak, Gyanendra Regmi

Laura J Banasiak Dr

Acidic groundwater generated from acid sulphate soil (ASS) is a major geo-environmental problem in Australia. A permeable reactive barrier (PRB) with recycled concrete aggregates as the reactive material has received considerable attention as an innovative, cost effective technology for passive treatment of acidic groundwater in ASS terrain. Laboratory column experiments conducted at the University of Wollongong investigated the acid neutralisation behaviour of recycled concrete and its potential to remove dissolved aluminium (Al) and iron (Fe). The recycled concrete effectively treated the acidic groundwater, resulting in near-neutral effluent pH and complete removal of Al and Fe. However, armouring of the concrete …

Benefits Of Geopolymer Concrete-Filled Frp Beams And Its Flexural Behavior, Wahid Ferdous, Allan Manalo, Amar Khennane, Obada Kayali

Wahid Ferdous

Thin Conductive Concrete Overlay For Bridge Deck Deicing And Anti-Icing, Sherif Yehia, Christopher Tuan

Christopher Y. Tuan

Concrete bridge decks are prone to ice accumulation. Bridge decks freeze before the roads approaching them freeze, making wintry highway travel treacherous. Road salts and deicing chemicals are effective for ice removal but cause damage to concrete and corrosion of reinforcing steel in concrete bridge decks. The resulting rapid degradation of existing concrete pavements and bridge decks is a major concern to transportation and public-works officials. The use of insulation materials for ice control and electric or thermal heating for deicing have been attempted, with unsatisfactory results. Conductive concrete is a cementitious admixture containing electrically conductive components to attain high …

Flexural Behavior Of Concrete-Filled Circular Steel Tubes Under High-Strain Rate Impact Loading, Yaohua Deng, Christopher Tuan

Christopher Y. Tuan

Nine simply supported circular steel concrete-filled tubes (CFTs), two circular steel posttensioned concrete-filled tubes (PTCFTs), and one circular steel fiber–reinforced concrete-filled tube (FRCFT) have been tested in an instrumented drop-weight impact facility. The weight and the height of the drop-weight were varied to cause failure in some test specimens. The failure modes and local damages in those specimens have been investigated extensively. Failure in the steel tubes was commonly tensile facture or rupture along the circumference. Concrete core in the impact area commonly crushed under compression and cracked under tension. The use of prestressing strands and steel fibers significantly restrained …

Conductive-Concrete Overlays - An Innovative Solution For Bridge Deck Deicing, Sherif Yehia, Christopher Tuan

Christopher Y. Tuan

Bridge decks are prone to ice accumulation, making winter travel treacherous. Road salts and some other deicing chemicals are cost effective, but may cause surface scaling, reinforcing-steel corrosion, or both. Another alternative is a thin, conductive-concrete overlay that, when connected to a power source, can generate enough heat through electrical resistance to prevent ice formation on the deck or melt ice after it forms. Using a conductive concrete overlay provides an environment-friendly deicing method that would prolong bridge service life by significantly reducing the use of road salt and deicing chemicals. When used on pedestrian bridges, sidewalks, and driveways, it …

Evaluation Of Use Of Lithium Nitrate In Controlling Alkali-Silica Reactivity In Existing Concrete Pavement, Christopher Tuan, Hoasu Sun

Christopher Y. Tuan

This study presents the findings from a 2-year field trial in which lithium nitrate was applied at a rate of 0.006 gal/ft2 twice a year on an existing concrete pavement in Norfolk, Nebraska, in an attempt to arrest ongoing alkali-silica reaction (ASR) distress. Various destructive and nondestructive means were used to measure the effectiveness of the treatments. Concrete cylinders were cored for petrographic examination and split tension testing. Powder samples were taken to determine the lithium content. Nondestructive evaluations used crack mapping, a Schmidt hammer, a velocity meter, and an impact echo apparatus. The amount of lithium that penetrated into …

Electrical Resistance Heating Of Conductive Concrete Containing Steel Fibers And Shavings, Christopher Tuan

Christopher Y. Tuan

Conductive concrete is a category of concrete containing electrically conductive components to attain stable and high electrical conductivity. Due to its electrical resistance and impedance, a thin conductive concrete overlay can generate enough heat to prevent ice formation on a bridge deck when connected to a power source. Steel fibers and steel shavings were used for the conductive materials in this study. A conventional concrete slab, 1.2 x 3.6 m (4 x 12 ft), has been constructed with a 9 cm (3.5 in.) conductive concrete overlay for conducting deicing experiments in the natural environment. The conductive concrete mixture was developed …

Agricultural Wastes As Aggregate In Concrete Mixtures – A Review, Hilmi Mahmud

Hilmi Mahmud

Concrete is the most widely used construction material. With the ever-increasing industrialization and urbanization, huge amounts of natural resources are required to make concrete. This, in turn, means that large volumes of natural resources and raw materials are being used for concrete production around the world. To eliminate or minimize the negative environmental impact of the concrete industry and promote environmental sustainability of the industry, the use of wastes from industry as materials for concrete making is considered as an alternative solution for preventing the excessive usage of raw materials. The wide availability of agricultural wastes make them a suitable …

Sources Of End Zone Cracking Of Pretensioned Concrete Girders, Christie J. Hasenkamp, Sameh S. Badie, Christopher Y. Tuan, Maher K. Tadros

Christopher Y. Tuan

Recent developments of high performance concrete, increasing amounts of prestressing, and increasing use of deep girders have resulted in increasing popularity of precast pretensioned concrete girders in bridge construction. These developments have increasingly contributed to end zone cracking. This paper summarizes the interim results of an ongoing research sponsored by the National Cooperative Highway Research Program (NCHRP) Project 18-14. The objectives of the research are: (1) to establish procedures for the acceptance, repair, or rejection of precast/prestressed concrete girders with longitudinal web cracking, and (2) to prepare a user's manual for the application of these procedures. The results from a …

Increasing The Flexural Stiffness Of Frp Wrapped Reinforced Concrete Columns, Muhammad Hadi, Veysel Yazici

Veysel Yazici

Axial load carrying capacity of reinforced concrete columns increase substantially after FRP wrapping. However, the same method also increases the lateral deformation capacity 61the columns especially under eccentric loads implying that secondary moments have to be considered when column are wrapped with FRP sheets under high level of axial loads. In this experimental study, six circular RC columns were cast and divided into two groups which were tested under 25 mm and 50 mm eccentric axial loads. Both groups had an unwrapped RC column, a three layers FRP wrapped column in the hoop direction, and a column which had discrete …

Normalized Confinement Stiffness Approach For Modeling Frp-Confined Concrete, Veysel Yazici, Muhammad N. S Hadi

Veysel Yazici

Passive confinement provided by fiber-reinforced polymer (FRP) jackets increases the compressive strength and axial deformation capacity of concrete. This study explains a normalized confinement stiffness approach to quantify the strength and strain increase of FRP confined concrete using a previously proposed and most widely-used model for both active and passive confinement of concrete, and claims that these equations can still be used for FRP-confined concrete with very simple modifications. A comparison of the proposed model's accuracy to American Concrete Institute guidelines was made using experimental results reported in the literature. The proposed modified model was shown to be quite effective …

Utilising Non-Composite Steel-Concrete-Steel Panels For Protective Structures, A M. Remennikov, S Y. Kong, Brian Uy

Alex Remennikov

A high-performance protective structure utilising non-composite steel-concrete-steel (SCS) sandwich panels for protecting buildings and facilities against close-range detonation of VBIEDs and heavy ve-hicle impacts has been developed. Unlike other existing composite sandwich panels, no shear connec-tors between the steel faceplates are utilised to construct protective panels in order to simplify the con-struction process. The concrete core of the panel is included to provide the mass for increased inertia effects, and the steel faceplates are designed to develop tensile membrane resistance at large displace-ment to dissipate impulsive energy. The energy dissipation capability and high ductility of the axially-restrained non-composite SCS panels …

Reliability-Based Conversion Of A Structural Design Code For Railway Prestressed Concrete Sleepers, A M. Remennikov, Martin Murray, Sakdirat Kaewunruen

Alex Remennikov

"Ballasted railway track is very suitable for heavy-rail networks because of its many superior advantages in design, construction, short- and long-term maintenance, sustainability, and life cycle cost. An important part of the railway track system, which distributes the wheel load to the formation, is the railway sleeper. Improved knowledge has raised concerns about design techniques for prestressed concrete (PC) sleepers. Most current design codes for these rely on allowable stresses and material strength reductions. However, premature cracking of PC sleepers has been found in railway tracks. The major cause of cracking is the infrequent but high-magnitude wheel loads produced by …

The Response Of Axially Restrained Non-Composite Steel-Concrete-Steel Sandwich Panels Due To Large Impact Loading, Alex M. Remennikov, Sih Ying Kong, Brian Uy

Alex Remennikov

In conventional steel-concrete-steel (SCS) construction, the external steel plates are connected to the concrete infill by welded shear stud connectors. This paper describes a programme of experimental and numerical investigations on reduced-scale non-composite SCS panels with axially restrained connections. The experimental results have demonstrated that the non-composite SCS panels are capable of developing enhanced load-carrying capacity through the tensile membrane resistance of the steel faceplates. This type of construction was found to exhibit highly ductile response and be able to sustain large end rotations of up to 18° without collapse. High fidelity finite element models for SCS panels under impact …

Simulation Of The Reinforced Concrete Slabs Under Impact Loading, Faham Tahmasebinia, Alexander Remennikov

Alex Remennikov

Many older structures were designed for static loads but more recently there has been a growing awareness that some must be designed to resist both dynamic impact and static loads. An accidental impact load can be caused by mishaps in industry as well as accidents stemming from transportation or man-made disasters. There are number of ways of predicting how an impact load will affect a concrete slab, some of which may be impractical or expensive but because there have been significant developments in technology, numerical techniques rather than experimental approaches have become popular methods for developing detailed responses Therefore, to …

End Zone Reinforcement For Pretensioned Concrete Girders, Christopher Y. Tuan, Sherif A. Yehia, Nipon Jongpitaksseel, Maher K. Tadros

Christopher Y. Tuan

In this study, a literature review was conducted to establish the background of current specifications and to evaluate the applicability of various theories and methods for design of end zone reinforcement. Analytical methods reviewed in this paper include finite element analysis, strut-and-tie modeling, and the Gergely-Sozen equivalent beam method. Previous experimental work combined with work conducted as part of this study was used to correlate between various theoretical and experimental results. This paper illustrates that no single theoretical method adequately represents the complex behavior at the end of a pretensioned concrete member. A general semi-empirical design procedure is proposed here. …

Curved, Precast, Pretensioned Concrete I-Girder Bridges, Wilast Amorn, Christopher Y. Tuan, Maher K. Tadros

Christopher Y. Tuan

Modern highway construction frequently requires bridges with horizontally curved alignments. Such bridges can be created by superimposing a curved deck slab onto straight girders or by splicing segmental straight girders on the chords of a curved roadway. Of these two methods, a curved superstructure usually results in simpler construction and better appearance.

Bond Strength And Transfer Length Of Pre-Tensioned Bridge Girders Cast With Self-Consolidating Concrete, Amgad Girgis, Christopher Tuan

Christopher Y. Tuan

Self-consolidating concrete (SCC) is becoming increasingly popular in the precast/prestressed concrete industry in the United States. However, there have been concerns regarding the bond strength, transfer length, and development length of prestressing strands and mild steel reinforcement with SCC. Further, there are no design guidelines for using SCC. In this study, a literature survey on the bond strength of SCC was conducted. Moustafa pullout tests were performed to determine the bond strength of 0.6 in. (15.2 mm) pretensioning strands with sec. The transfer lengths of three pretensioned concrete bridge girders were measured using Demec points. Pullout tests were also performed …

Hybrid Frp-Concrete Railway Sleeper, Wahid Ferdous, Amar Khennane, Obada Kayali

Wahid Ferdous

The aim of this research was to investigate the feasibility of a hybrid FRP-concrete beam as a rail sleeper. It was hoped that the new design would overcome some of the sustainability issues associated with traditional sleepers. The hybrid system consisted of a Rectangular Hollow Section (RHS) pultruded profile filled with geo- polymer concrete. The specimens were tested in a four-point bending setup to determine the flexural properties such as the bending modulus (E) and modulus of rupture (MOR). It was found that the proposed composite beam satisfied the minimum flexural requirements for composite railway sleepers as stated in the …

Affordable Lightweight High Performance Concrete (Alwhpc) - Expanding The Envelope Of Concrete Mix Design, Kevin J. Simons

Kevin J Simons

One way to reduce excess material would be to lighten the load on a structure with the use of affordable lightweight high performance concrete (ALWHPC). Most or all lightweight high performance concrete mixes used today include lightweight aggregates as the coarse aggregate and sand for the fine aggregate. ALWHPC mix designs contain all lightweight aggregates and cementitious materials that are readily available throughout the United States. Instead of 115 – 120 pcf, ALWHPC mix designs range from 88 – 100 pcf and strengths from 2,700 – 8,700 psi compressive strength. This research will explore the use of local lightweight aggregates …

Evaluating Waste Concrete For The Treatment Of Acid Sulphate Soil Groundwater From Coastal Floodplains, Gyanendra Regmi, Buddhima Indraratna, Long Nghiem, Laura Banasiak

Long D Nghiem

The treatment of acidic groundwater generated from acid sulphate soil (ASS) terrain is a challenging environmental issue in coastal floodplains of Australia. In this study, a laboratory column experiment was conducted to assess the performance of waste concrete for treating the acidic groundwater leachate from ASS terrain of the Shoalhaven region of NSW. The groundwater was highly acidic (pH of 2.5–3.5) and contained elevated concentrations of iron (10–90 mg/L) and aluminium (30–45 mg/L). Passage of the acidic groundwater through the column filled with waste concrete resulted in a significant improvement in water quality. Reduction in the concentration of iron and …

A Neural Network Approach To Predict The Performance Of Recycled Concrete Used In Permeable Reactive Barriers For The Treatment Of Acidic Groundwater, B Guruprasad, Buddhima Indraratna, Long Nghiem, G Regmi

Long D Nghiem

This study developed a neural network model for examining the performance of recycled concrete for the treatment of acidic groundwater. Concentrations of Al, Fe and Ca and alkalinity of the effluent were selected as the output parameters to simulate the performance of recycled concrete for neutralizing acidic groundwater. The input variables were the number of pore volumes, pH, oxidation reduction potential and the average hydraulic conductivity. Of the 658 experimental datasets available, 409 datasets were used for training, 184 datasets were used for validation, and the remaining datasets were used for cross-validation. The reported results indicate that the neural model …

Treatment Of Acidic Groundwater In Acid Sulfate Soil Terrain Using Recycled Concrete: Column Experiments, Gyanendra Regmi, Buddhima Indraratna, Long Nghiem, A. Golab, B Guru Prasad

Long D Nghiem

Acidic groundwater generated from pyrite oxidation in acid sulfate (AS) soil is a major geoenvironmental problem in Australia. This study aims to evaluate recycled concrete as a reactive material in permeable reactive barriers (PRBs) for the remediation of acidic groundwater in low-lying AS soil floodplains. Laboratory experiments were systematically conducted to investigate the acid neutralization behavior of recycled concrete and its potential to remove dissolved Al and Fe. The results confirmed that recycled concrete could effectively treat acidic groundwater from an AS soil terrain, resulting in near neutral effluent over a long period with complete removal of Al and Fe. …

Armouring By Precipitates And The Associated Reduction In Hydraulic Conductivity Of Recycled Concrete Aggregates Used In A Novel Prb For The Treatment Of Acidic Groundwater, Punyama Pathirage, Buddhima Indraratna, Long Duc Nghiem, Laura Banasiak, Gyanendra Regmi

Long D Nghiem

Acidic groundwater generated from acid sulphate soil (ASS) is a major geo-environmental problem in Australia. A permeable reactive barrier (PRB) with recycled concrete aggregates as the reactive material has received considerable attention as an innovative, cost effective technology for passive treatment of acidic groundwater in ASS terrain. Laboratory column experiments conducted at the University of Wollongong investigated the acid neutralisation behaviour of recycled concrete and its potential to remove dissolved aluminium (Al) and iron (Fe). The recycled concrete effectively treated the acidic groundwater, resulting in near-neutral effluent pH and complete removal of Al and Fe. However, armouring of the concrete …