Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
Articles 1 - 18 of 18
Full-Text Articles in Engineering
Conductive Concrete For Electromagnetic Shielding – Methods For Development And Evaluation, Aaron P. Krause
Conductive Concrete For Electromagnetic Shielding – Methods For Development And Evaluation, Aaron P. Krause
Computer and Electronics Engineering: Dissertations, Theses, and Student Research
This research investigates the development and evaluation innovative methods for the use of conductive concrete as an electromagnetic shield. New testing methods are developed to determine the best conductive components to use in the design of a concrete mixture for shielding that shows the best promise. The conductive concrete mixture has the potential to provide electromagnetic shielding that is cost-effective in terms of construction, operation, and maintenance compared to conventional approaches. Two testing methods, Small Sample Testing and Large Slab Testing, are developed based on standardized testing methods that have been modified for the testing of conductive concrete mixtures. As …
Incorporation Of Life Cycle Models In Determining Optimal Wind Energy Infrastructural Provision, Brendan Cleary, Aidan Duffy, Alan O'Connor
Incorporation Of Life Cycle Models In Determining Optimal Wind Energy Infrastructural Provision, Brendan Cleary, Aidan Duffy, Alan O'Connor
Conference papers
The deployment of wind energy has grown rapidly over the last two decades with an average annual growth rate of more than 26% since 1990. During this period the development and innovation of wind turbines has resulted in continual growth in wind turbine size with output ranges of 10-15MW likely to be deployed by 2020. This increased output has a knock-on effect on the growth of rotor diameters and tower heights. Wind turbine towers are required to become taller, stronger and stiffer in order to carry the increased weight and associated structural loading. Consequently, the dimensions of the tower cross-sections …
Limit States Design Of Railway Concrete Sleepers, Sakdirat Kaewunruen, Alexander Remennikov, Martin H. Murray
Limit States Design Of Railway Concrete Sleepers, Sakdirat Kaewunruen, Alexander Remennikov, Martin H. Murray
Faculty of Engineering - Papers (Archive)
The recently updated information has raised a concern in not only the existing costineffective design method but also the unrealistic analysis mode of railroad prestressed concrete sleepers. Because of the deficient knowledge in the past, railway civil engineers have been mostly aware of the over conservative design methods for structural components in any railway track, which rely on allowable stresses and material strength reductions. Based on a number of proven experiments and field data, it is believed that the concrete sleepers complied with the allowable stress concept possess the unduly untapped fracture toughness. A collaborative research run by the Australian …
Inelastic Stability Analysis Of High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Vipulkumar Ishvarbhai Patel, Qing Quan Liang, Muhammad N. S Hadi
Inelastic Stability Analysis Of High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Vipulkumar Ishvarbhai Patel, Qing Quan Liang, Muhammad N. S Hadi
Faculty of Engineering - Papers (Archive)
There is relatively little numerical study on the behavior of eccentrically loaded high strength rectangular concrete-filled steel tubular (CFST) slender beam-columns with large depth-to-thickness ratios, which may undergo local and global buckling. This paper presents a multi scale numerical model for simulating the interaction local and global buckling behavior of hlgh strength thin-walled rectangular CFST slender beam-columns under eccentric loading. The effects of progressive local buckling are taken into account in the mesoscale model based on fiber element formulations. Computational algorithms based on the Muller's method are developed to obtain complete load-deflection responses of CFST slender beam-columns at the macroscale …
Comparative Behaviour Of Frp Confined Square Concrete Columns Under Eccentric Loading, X Lei, Thong M. Pham, M N. S Hadi
Comparative Behaviour Of Frp Confined Square Concrete Columns Under Eccentric Loading, X Lei, Thong M. Pham, M N. S Hadi
Faculty of Engineering - Papers (Archive)
This study evaluates different methods of strengthening existing square concrete columns under eccentric loading. Sixteen reinforced square concrete columns were cast. The columns were made from normal strength concrete and the reinforcement was kept at minimum simulating columns needing retrofitting. Four columns were modified with round comers and wrapped with three layers of CFRP, four were circularised by circular segments and wrapped with three layers of CFRP, and the last four columns were circularised and confined with steel straps. Specimens from each group were tested under concentric, eccentric (15 or 25 mm) and flexural bending. Results from the study showed …
Normalized Confinement Stiffness Approach For Modeling Frp-Confined Concrete, Veysel Yazici, Muhammad N. S Hadi
Normalized Confinement Stiffness Approach For Modeling Frp-Confined Concrete, Veysel Yazici, Muhammad N. S Hadi
Faculty of Engineering - Papers (Archive)
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 …
Drying Shrinkage Of Concrete Made From Recycled Concrete Aggregate, B A. Whiting, T J. Mccarthy, E Lume
Drying Shrinkage Of Concrete Made From Recycled Concrete Aggregate, B A. Whiting, T J. Mccarthy, E Lume
Faculty of Engineering and Information Sciences - Papers: Part A
Recycled concrete aggregates (RCA) are used in new concrete mixes, termed recycled aggregate concrete (RAC). Among losses in most fresh and hardened properties, literature reports that RAC suffers increased levels of drying shrinkage compared to equivalent mixes incorporating conventional aggregates. This paper describes the procedure and results of a range of experiments conducted on a commercial RCA and its use in new concrete mixes. In particular, this work quantifies the effect 100% RCA has on the drying shrinkage of the resulting concrete. A commercially available RCA was characterised by analysing the particle shape and texture, percentage of solid contaminants, particle …
Behaviour Of Frp Confined Concrete Cylinders Under Different Temperature Exposure, Muhammad N. S Hadi, B A. Louk Fanggi
Behaviour Of Frp Confined Concrete Cylinders Under Different Temperature Exposure, Muhammad N. S Hadi, B A. Louk Fanggi
Faculty of Engineering - Papers (Archive)
Bridge structures are exposed to the elements with a high variation in temperature. The purpose of this study is to investigate the effect of different high temperatures on the behaviour of concrete cylinders wrapped with Fibre Reinforced Polymer (FRP). Twelve concrete cylinders made of 60 MPa having 100 mm diameter and 200 mm height were cast and tested. The cylinders were divided into four groups: cylinders wrapped with a single CFRP layer, cylinders wrapped with two CFRP layers, cylinders wrapped with a single GFRP layer, and cylinders wrapped with two GFRP layers. Each group was exposed to temperatures of 20°C, …
Stress-Strain Model For Concrete Under Cyclic Loading, Farhad Aslani, Raha Jowkarmeimandi
Stress-Strain Model For Concrete Under Cyclic Loading, Farhad Aslani, Raha Jowkarmeimandi
Faculty of Engineering - Papers (Archive)
A hysteretic stress-strain model is developed for unconfined concrete with the intention of providing efficient modelling for the structural behaviour of concrete in seismic regions. The proposed model is based on the findings of previous experimental and analytical studies. The model for concrete subjected to monotonic and cyclic loading comprises four components in compression and tension - an envelope curve (for monotonic and cyclic loading), an unloading curve, a reloading curve and a transition curve. Formulations for partial unloading and partial reloading curves are also presented. The reliability of the proposed constitutive model is investigated for a reinforced concrete member …
High Strength Thin-Walled Rectangular Concrete-Filled Tubular Slender Beam-Columns, Part Ii: Behaviour, Muhammad N. S Hadi, Qing Quan Liang, Vipulkumar I. Patel
High Strength Thin-Walled Rectangular Concrete-Filled Tubular Slender Beam-Columns, Part Ii: Behaviour, Muhammad N. S Hadi, Qing Quan Liang, Vipulkumar I. Patel
Faculty of Engineering - Papers (Archive)
Experimental and numerical research on full-scale high strength thin-walled rectangular steel slender tubes filled with high strength concrete has not been reported in the literature. In a companion paper, a new numerical model was presented that simulates the nonlinear inelastic behavior of uniaxially loaded high strength thin-walled rectangular concrete-filled steel tubular (CFST) slender beam-columns with local buckling effects. The progressive local and post-local buckling of thin steel tube walls under stress gradients was incorporated in the numerical model. This paper presents the verification of the numerical model developed and its applications to the investigation into the fundamental behavior of high …
Performance Of Cfrp Wrapped Square Reinforced Concrete Columns Subjected To Eccentric Loading, Ida Bagus Rai Widiarsa, Muhammad N. S Hadi
Performance Of Cfrp Wrapped Square Reinforced Concrete Columns Subjected To Eccentric Loading, Ida Bagus Rai Widiarsa, Muhammad N. S Hadi
Faculty of Engineering - Papers (Archive)
Strengthening concrete columns with fibre-reinforced polymer (FRP) has been tudied extensively, but the majority of published tudies have focllsed on circular column. Most concrete columns in the field have square 01' r ctangul3r cross ections and resist ecc nt.ric loading as well. The objective of this study i to investigate the performance of square reinforced concrete (RC) columns wrapped with carbon FRP subjected to eccentric Loading. The influence of two parameters was studied including the number of FRP layers and the magnitude of eccentricity. Compression testing was conducted on twe Ive short quare RC columns wrapped with CFRP composites. The …
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
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
Faculty of Engineering - Papers (Archive)
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 …
Nonlinear Analysis Of Biaxially Loaded High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Part I: Theory, Qing Quan Liang, Vipulkumar Ishvarbhai Patel, Muhammad N. S Hadi
Nonlinear Analysis Of Biaxially Loaded High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Part I: Theory, Qing Quan Liang, Vipulkumar Ishvarbhai Patel, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a new numerical model for the nonlinear inelastic analysis of biaxially loaded high strength thin-walled rectangular concrete-filled steel tubular (CFST) slender beam-columns. The numerical model considers the effects of progressive local buckling, initial geometric imperfections, high strength materials and second order. The accurate fiber element method is used to model the inelastic behavior of composite cross-sections. Theoretical models are developed that simulate the load-deflection responses and strength envelopes of thin-walled rectangular CFST slender beamcolumns under biaxial loads. New computational algorithms based on the M ller's method are developed to adjust the depth and orientation of the neutral …
Hybrid Frp-Concrete-Steel Double-Skin Tubular Columns: Cyclic Axial Compression Tests, Tao Yu, Yu-Bo Cao, Bing Zhang, J G. Teng
Hybrid Frp-Concrete-Steel Double-Skin Tubular Columns: Cyclic Axial Compression Tests, Tao Yu, Yu-Bo Cao, Bing Zhang, J G. Teng
Faculty of Engineering and Information Sciences - Papers: Part A
Hybrid FRP-concrete-steel double-skin tubular columns (hybrid DSTCs) are a new form of hybrid columns recently developed at The Hong Kong Polytechnic University. A hybrid DSTC consists of an inner steel tube, an outer FRP tube and a concrete infill between the two tubes. Hybrid DSTCs possess many important advantages over existing column forms, including their excellent corrosion resistance and excellent seismic resistance. While a large amount of research has been conducted on the monotonic behavior of this novel form of columns, only a limited amount of work has been conducted on their behavior under cyclic loading. This paper presents the …
Utilising Non-Composite Steel-Concrete-Steel Panels For Protective Structures, A M. Remennikov, S Y. Kong, Brian Uy
Utilising Non-Composite Steel-Concrete-Steel Panels For Protective Structures, A M. Remennikov, S Y. Kong, Brian Uy
Faculty of Engineering and Information Sciences - Papers: Part A
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 …
Non-Uniform Stress Distribution In Frp-Wrapped Circular Concrete Columns Under Uniform Axial Deformation, S Q. Li, J F. Chen, Tao Yu, J G. Teng
Non-Uniform Stress Distribution In Frp-Wrapped Circular Concrete Columns Under Uniform Axial Deformation, S Q. Li, J F. Chen, Tao Yu, J G. Teng
Faculty of Engineering and Information Sciences - Papers: Part A
The confinement of concrete columns using bonded FRP wraps has become a popular retrofit technique. Through extensive research in the last two decades, many stress-strain models have been developed for concrete in FRP-wrapped circular columns. All these models assume that the stress state is axisymmetric in an FRP-wrapped circular concrete column under concentric axial compression. This implies that the FRP wrap is assumed to be axisymmetric in geometry, but in reality such axisymmetry is not realised due to the existence of an overlapping zone. This paper presents a finite element investigation into the stress state in FRP-wrapped circular concrete columns …
Reliability-Based Conversion Of A Structural Design Code For Railway Prestressed Concrete Sleepers, A M. Remennikov, Martin Murray, Sakdirat Kaewunruen
Reliability-Based Conversion Of A Structural Design Code For Railway Prestressed Concrete Sleepers, A M. Remennikov, Martin Murray, Sakdirat Kaewunruen
Faculty of Engineering and Information Sciences - Papers: Part A
"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 …
Nonlinear Inelastic Behavior Of Circular Concrete-Filled Steel Tubular Slender Beam-Columns With Preload Effects, Vipulkumar Ishvarbhai Patel, Qing Quan Liang, Muhammad N. Hadi
Nonlinear Inelastic Behavior Of Circular Concrete-Filled Steel Tubular Slender Beam-Columns With Preload Effects, Vipulkumar Ishvarbhai Patel, Qing Quan Liang, Muhammad N. Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a numerical model based on fiber element formulations for simulating the nonlinear inelastic behavior of eccentrically loaded circular concrete-filled steel tubular (CFST) slender beam-columns with preload effects. Deflections caused by preloads are included in the global analysis of CFST slender beam-columns as initial geometric imperfections. Computational algorithms based on the Müller's method are developed to obtain load-deflection responses of CFST slender beam-columns including preload effects. The accuracy of the numerical model is examined by comparisons of computer solutions with experimental results. The numerical model is utilized to investigate the effects of preloads on the axial load-deflection curves, …