Structural Engineering Commons^™

Use Of Coconut Shell As An Aggregate In Concrete: A Review, Sourav Ghosal, S. C. Moulik

Innovative Research Publications IRP India

Now-a-days, the rising cost of building materials for construction purposes is a factor of great concern. The price of building materials is rising day by day. Now, most of the researchers are paying much attention on the suitable materials which can reduce the cost of construction as well as increase the strength properties of concrete. Mainly gravel and sand are used in the preparation of conventional concrete. While the use of an agricultural by-product i.e. coconut shell as a partial replacement with conventional coarse aggregates is expected to serve the purpose of encouraging housing developers in building construction. Environmental impact …

International Conference On Short And Medium Span Bridges, Calgary, July 15-18, 2014, Barry A. Palynchuk Phd, Christophe Deniaud Phd

Barry A. Palynchuk PhD

The Jean River near Wabush, Labrador is crossed by two railways and an access road by twin 6m diameter culverts . They are heavily strutted inside their barrels to counteract some significant shape deformation, and are deemed not suitable to sustain the increased volume of rail traffic serving the development of the Bloom Lake mines. The owner requested the design and construction of a replacement scheme for an additional design life of 20 years with a time sensitive schedule for completion of the work during the 2013 construction season. This VE concept for the design of live load relief spans …

No Admixture, Sustainable, Self-Consolidating Grout, Craig V. Baltimore Dr

Craig V. Baltimore

ABSTRACT: The consolidation of grout in concrete masonry unit (CMU) walls is labor-intensive. Also, the grout’s Portland cement content has a high embodied energy demand – a non-sustainable characteristic. For the labor-intensive issue, chemical admixture self-consolidating grouts have been used in walls 12.67 ft. (3.86 m) tall, however the chemical additive can impose new limitations on the grout (non-robust characteristics). No admixture self-consolidating grout with high percentage Portland cement replacement have potential for robust and sustainable application.

This paper reports on the consolidation of no admixture self-consolidating grout made by substituting high percentages of Portland cement with Type-F fly ash …

Cable Connected Active Tuned Mass Dampers For Control Of In-Plane Vibrations Of Wind Turbine Blades, Breiffni Fitzgerald

Breiffni Fitzgerald

In-plane vibrations of wind turbine blades are of concern in modern multi-megawatt wind turbines. Today׳s turbines with capacities of up to 7.5 MW have very large, flexible blades. As blades have grown longer the increasing flexibility has led to vibration problems. Vibration of blades can reduce the power produced by the turbine and decrease the fatigue life of the turbine. In this paper a new active control strategy is designed and implemented to control the in-plane vibration of large wind turbine blades which in general is not aerodynamically damped. A cable connected active tuned mass damper (CCATMD) system is proposed …

Bridge-Track Interaction Under Elevated Temperatures, Sakdirat Kaewunruen

Sakdirat Kaewunruen

This paper presents the adaptability to short-term climate variability and extreme events of existing infrastructures in Australia, especially railway track bridges. The main objective of this research was to analyse the interaction between the track and bridge under elevated temperatures. The scope of work was to evaluate the behaviour of the track and bridge interaction throughout temperature ranges experienced in summer periods whereas the expansion and contraction of materials are different in nature. This investigation was emphasised on the differential longitudinal behaviours of railway track and bridge structure. A nonlinear 3D finite element model of a railway bridge (ballast top) …

Advances In Rail Track Infrastructure Research And Practice, Manicka Dhanasekar, Alex M. Remennikov, Sakdirat Kaewunruen, Nannan Zong

Sakdirat Kaewunruen

Railway infrastructure plays a critical role in urban development, mobility, and economic growth of society. This focus issue of the Electronic Journal of Structural Engineering is devoted to a special theme, “Advances in Rail Track Infrastructure and Practice - ARTRP”. It contains articles, which were rigorously peer reviewed and accepted from a list of invited manuscripts that demonstrate significant innovation in the area of the structural engineering aspects of the rail track infrastructure. Over the past century or two, rail industry slowly but steadily evolved through significant innovations in the industry; academic research in rail is relatively new. Rail is …

Railway Bridge-Track Interaction Under Elevated Temperatures, Sakdirat Kaewunruen

Sakdirat Kaewunruen

This paper presents the adaptability to short-term climate variability and extreme events of existing infrastructures in Australia, especially railway track bridges. The main objective of this research was to analyse the interaction between the track and bridge under elevated temperatures. The scope of work was to evaluate the behaviour of the track and bridge interaction throughout temperature ranges experienced in summer periods whereas the expansion and contraction of materials are different in nature. This investigation was emphasised on the differential longitudinal behaviours of railway track and bridge structure. A nonlinear 3D finite element model of a railway bridge (ballast top) …

Decorative Ferrocement Elements, Letitia Nadasan, Traian Onet, Ana Ioana Petean, Marian Sabau

Marian Sabau

Ferrocement has the versatility that can be 'sculptured' or shaped into numerous fascinating structures and objects for very wide applications. The exposure of this technology to engineers in general is rather minimal in Romania and many are skeptical about it. The potential is not exploited for it being unconventional in nature. Its ability to compete or use as a cheaper alternative and yet a promising technology in ensuring improved living standard and environmental quality must not be neglected. The paper discusses about the applicability of ferrocement in the Romanian scene with respect to recreation and home use. The ferrocement elements …

Acoustic And Dynamic Characteristics Of A Complex Urban Turnout Using Fibre-Reinforced Foamed Urethane (Ffu) Bearers, Sakdirat Kaewunruen

Sakdirat Kaewunruen

A special track system used to divert a train to other directions or other tracks is generally called ‘railway turnout’. A traditional turnout system includes rails, switches, crossings (special track components), steel plates, fasteners, screw spikes, timber bearers, ballast and formation. The wheel rail contact over the crossing transfer zone has a dip-like shape and can often cause detrimental impact loads on the railway track and its components. The large impact also emits disturbing noises (either impact or ground-borne noise) to railway neighbors. In a brown-field railway track where an existing aged infrastructure requires renewal or maintenance, some physical constraints …

Evaluation Of In-Ground Plastic-Hinge Length And Depth Recommendations For Piles In Marine Oil And Lng Terminals, Rakesh K. Goel

Rakesh K. Goel

This investigation evaluated the current recommendations for plastic-hinge length and depth for pre-stressed concrete and hollow-steel piles for different soil conditions typical of those in Marine Oil and LNG Terminals. Nonlinear behavior for both pile and soil were considered and MOTEMS specified strain levels were used to compute the pile capacity. All analyses in this study were conducted using OpenSees software developed at the Pacific Earthquake Engineering Research Center. The approach used in this investigation for estimating the plastic-hinge length and depth is similar to that used in development of current MOTEMS recommendations. This investigation led to several important findings …

Experimental Determination On Bond Strength Of Rebar In Self-Compacting Concrete, Marian Sabau, Traian Onet, Ana Ioana Petean

Marian Sabau

Experimental results of the local bond stress-slip relationship of deformed reinforcing bars embedded in confined self-compacting concrete are presented. A total of 58 pull-out specimens were tested. Each one of these specimens simulated the confined region of a beam-column joint. The main analyzed parameters were the concrete type, the confining reinforcement, the reinforcement bar diameter, the embedded length of bars. The results showed that in order to ensure that the bond failure is caused by pull-out, a restraining reinforcement must be provided. The paper also presents a comparison between self-compacting concrete (SCC) and normally vibrated concrete (NVC).

Economia De Energie Realizată Prin Folosirea Betonului Autocompactant, Marian Sabau, Traian Onet, Ana Ioana Petean, Letitia Nadasan

Marian Sabau

Betonul autocompactant (BAC) este un beton inovativ care nu necesită vibrare în momentul punerii în operă, acesta fiind capabil să curgă sub propia greutate, poate să umple complet cofrajele şi să ajungă la o compactare corespunzătoare fără a fi nevoie de o compactare mecanică. Această lucrare prezintă avantajele acestui nou tip de beton, materialele constituente, metodele de testare, precum şi dezavantajele care le aduce compactarea prin vibrare asupra betonului obişnuit. Eliminarea vibrării are de asemenea efecte benefice asupra condițiilor de muncă în procesul de producere al betonului.

Effect Of Confinement On Bond Strength Between Self-Compacting Concrete And Reinforcement, Marian Sabau, Traian Onet, Ana Ioana Petean

Marian Sabau

Slippage of the beam reinforcement at beam–column connections is an important cause of damage of reinforced frames under static and dynamic loads. This paper presents the effects of confinement in self-compacting concrete (SCC), on the local bond stress vs. slip characteristics of deformed bars in reinforced concrete joints. Prismatic specimens with deformed steel bars embedded for a fixed length equal to three and five equivalent diameters were tested under monotonic loading. The specimens represented the confined region of a beam–column connection. The obtained results indicated that as far as the bond splitting cracks are restrained by reinforcing bars crossing these …

Active Tuned Mass Dampers For Control Of In-Plane Vibrations Of Wind Turbine Blades, Breiffni Fitzgerald

Breiffni Fitzgerald

This paper investigates the use of active tuned mass dampers (ATMDs) for the mitigation of in-plane vibrations in rotating wind turbine blades. The rotating wind turbine blades with tower interaction represent time-varying dynamical systems with periodically varying mass, stiffness, and damping matrices. The aim of this paper is to determine whether ATMDs could be used to reduce in-plane blade vibrations in wind turbines with better performance than compared with their passive counterparts. A Euler–Lagrangian wind turbine mathematical model based on energy formulation was developed for this purpose, which considers the structural dynamics of the system and the interaction between in-plane …

Active Tuned Mass Damper Control Of Wind Turbine Nacelle/Tower Vibrations With Damaged Foundations, Breiffni Fitzgerald

Breiffni Fitzgerald

The aim of this paper is to develop an active structural control scheme to control wind turbine nacelle/tower out-of-plane vibration. An active tuned mass damper (ATMD) is designed an placed inside the turbine nacelle. An EulerLagrangian wind turbine model based on energy formulation is developed for this purpose, which considers the structural dynamics of the system and the interaction between in-plane and out-of-plane vibrations. Also, the interaction between the blades and the tower including the ATMD is considered. The wind turbine is subjected to gravity and turbulent aerodynamic loadings. A three-dimensional (3D) model of a wind turbine foundation is designed …

Bond Between Self-Compacting Concrete And Reinforcement, Marian Sabau, Traian Onet, Ioan Pop

Marian Sabau

This paper study the bond behaviour of self-compacting concrete (SCC) in comparison to normal vibrated concrete (NVC). In this paper are presented the following parameters: the influence of bar diameter, the influence of concrete quality, the top-bar effect, the influence of active and passive confinement. In literature, different test results are found for the bond strength in SCC, which deliver contradictory results, but internationally it seems to be agreed that bond strength in SCC is slightly higher than NVC.

Hardened Properties Of Self-Compacting Concrete, Marian Sabau, Traian Onet, Ana Ioana Petean

Marian Sabau

This paper presents the properties of hardened self-compacting concrete (SCC) and compare them to those reported for normally vibrated concrete (NVC). The mechanical properties evaluated are: compressive strength, modulus of elasticity, tensile strength, creep, shrinkage and bond with reinforcement. The very wide range of materials and mixes already used for SCC produced a significant scatter of data, but clear conclusions have been obtained. The compressive strength of SCC was likely to be the same or greater than that of NVC by using the same content of cement and water. Modulus of elasticity of SCC was lower than that of NVC …

Experimental Verification Of The Linear Relationship Between Stress And The Reciprocal Of The Peak Barkhausen Voltage In Astm A36 Steel, Orfeas Kypris, Ikenna Nlebedim, David Jiles

Orfeas Kypris

This study presents an experimental validation of a model theory for determining the relationship between a nondestructive measurement parameter and a property of interest. It was found that the reciprocal of the peak envelope amplitude of the Barkhausen emission voltage follows a linear relationship with stress. A linear relationship between stress and the reciprocal of the root mean square voltage was also obtained. These observations represent an important step towards improving the use of Barkhausen signals for magnetic non-destructive evaluation of stress as a function of depth in ferromagnetic load bearing structures.

Application Of Gis In Seismic Risk Assessment For The City Of Kelowna, Md. Nurul Alam

Md. Nurul Alam

No abstract provided.

Nonlinear Concrete Behaviour, Marian Sabau, Traian Onet

Marian Sabau

This paper presents an overview of nonlinear behaviour in reinforced concrete structures. Structural concrete is a nonlinear material both at strength limit states and service loads. Are presented terms of effects that are primarily observed in concrete, steel or a combination of the two. When considering nonlinear behaviour, an important aspect is whether or not strain localization will occur as size effects. The model must first be validated by experiments and benchmark tests to ensure the safety and reliability criteria. In nonlinear finite element procedures, engineers must check their finite element discretization and modelling assumptions used in their analyses. Advanced …

Torsional Behavior Of Prestressed Concrete Beams Strengthened With Cfrp Sheets, Akram Shaker Mahmood, Mohamed Najim Mahmood

Akram Shaker Mahmood

Strengthening of concrete structures with externally bonded carbon fiber reinforced polymers (CFRPs) has been a viable technique for at least a decade and it became interesting material and applied in strengthening reinforced and prestressed concrete beams. It has been found that CFRP sheets are very suitable; not only because of its strength, but also due to its ease of application in comparison to traditional strengthening systems. Despite the fact that CFRP has been widely used in strengthening reinforced concrete members, a very limited works were found in the literature that is related to the application of CFRP in assessing the …

Application Of Event Tree Analysis In Wildfire Risk Assessment For The City Of Kelowna, Md. Nurul Alam

Md. Nurul Alam

The devastating inferno of the Okanagan Mountain Park Fire of 2003, which caused significant damage to infrastructure, home, private properties and caused evacuation of affected people from the City of Kelowna. Consequently, it raised the importance of conducting a risk assessment for the City. This study focused on analyzing the existing risks from wild fire, and the estimation of loss and damage with the help of proposed event tree method for the City of Kelowna. Finally, the risky areas have been represented spatially with the help of geographic information system (GIS) to provide a basis for an effective decision making …

01june2010_Building Collapse_Begunbari, Md. Nurul Alam

Md. Nurul Alam

No abstract provided.

Nonlinear Finite Elements Modeling Of Hybrid Reinforced Concrete Beams, Akram Shaker Mahmood

Akram Shaker Mahmood

This paper presents results from a nonlinear finite element analysis of a hybrid reinforced concrete rectangular section beams. The concept of hybrid R.C. concrete structures was applied in many designers for using in constructions of bridge superstructure. Although using the steel reinforcements are often modeled as a linear-elastic material until failure, the linear finite element analysis could not predict the behavior of the R.C. concrete beams model up to its failure. The materials, loadings, section properties with boundary conditions are taken from reference [Ref.3]. Results from material tests and loading tests of beams model indicated that the nonlinearity of concrete …

Damage Detection In Wind Turbine Blades Using Time-Frequency Analysis Of Vibration Signals, Breiffni Fitzgerald

Breiffni Fitzgerald

The dynamic behaviour of modern multi-Megawatt wind turbines has become an important design consideration. One of the major aspects related to the reliability of operation of the turbines concerns the safe and adequate performance of the blades. The aim of this paper is to develop a time-frequency based algorithm to detect damage in wind turbine blades from blade vibration signals. It is important that damage to blades is detected before they fail or cause the turbine to fail. A wind turbine model was developed for this paper. The parameters considered were the rotational speed of the blades and the stiffness …

Nonlinear Finite Element Analysis Of Polymer Members, Akram Shaker Mahmood, Arz Y. Rzayeg

Akram Shaker Mahmood

An investigation study is made for verify the behavior of polymer members (Epoxsy & Polyester). The results of nonlinear analysis are illustrated with experimental work results. The ANSYS model accounts for nonlinear material phenomenon, such as, Tension Softening Material (TSM) and Enhanced Multilinear Isotropic Softening (EMIS) models. The polymer specimens are modeled using PLANE82 element – eight node plane element -, which is capable of simulating the failure behavior of polymer material members. The intention of this paper is thereby to discuss the proposed softening models to validate the complete Stress-Strain and Load-Deflection response of prismatic specimens subjected to uniaxial …