Download or read book Environmental Durability of Bond Behaviour Between Steel and Carbon Fibre Reinforced Polymer written by Tien Cuong Nguyen and published by . This book was released on 2012 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the last three decades, many studies have proven the effective use of CFRP composites in strengthening and retrofitting steel structures. However, one of the main restrictions to more widespread use of CFRP in strengthening and rehabilitating steel structures has been the uncertainty in the durability of steel/CFRP adhesively-bonded systems. This is especially true when such systems are exposed to outdoor environments. The data reporting this issue in the literature is currently limited and thus a systematic investigation of the effects of outdoor environments are required.The outdoor environments mainly include temperature, moisture and ultraviolet.Temperature is a detrimental factor to the adhesive layer between steel and CFRP because it may reach the glass transition temperature (Tg) of the adhesive,leading to a rapid reduction in the bond strength. Moisture, as another aspect of the durability, by diffusion through the adhesive or transport along the oxide/adhesive interface or absorption through the porous adherend, can penetrate to the interfaces between the adhesive and the steel adherend. Once moisture has penetrated into the steel /CFRP systems, degradation can occur due to two types of degradation: the degradation of the adhesive itself, and the degradation of the adhesive/adherend interface. In terms of ultraviolet, although the Earth's atmosphere filters out most of the total solar radiation, 6% of the total solar radiant flux is ultraviolet radiation and is able to reach the Earth's surface. Ultraviolet radiation has a wavelength between 290 and 400 nm, and the energy created by these wavelengths can dissociate the molecule bonds inivmost polymers, leading to the degradation of polymeric materials. The degradation may range from mere surface discoloration to extensive loss of mechanical properties. It should be also mentioned that combining these degrading factors together with loading may cause a significant degradation in mechanical properties of steel /CFRP systems.Double strap joints were chosen to investigate the performance of steel/CFRP composite systems subjected to environmental effects. When a double strap joint is tensioned, the strain in the carbon fibres must develop directly from the bond between the metal and the fibre. In this way, the fundamental behaviour of the metal-fibre bond, including the maximum strength and the effective bond length, can be investigated under static load.In the present research, the first aim was to investigate the effects of elevated temperatures on the mechanical characteristics of steel /CFRP double strap joints. It was found that due to elevated temperatures, the joint failure mode changed from cohesion to CFRP and adhesive interface debonding. Effective bond length was found to rapidly increase. Finally, joint strength and stiffness significantly decreased with temperature especially when temperature reached above the glass transition temperature (Tg) of the adhesive. Based on the ultimate load prediction model developed by Hart-Smith for double lapjoints and kinetic modeling of the mechanical degradation of the adhesive, a mechanism-based model is proposed to describe the change of effective bond length, stiffness and strength degradation for steel/CFRP double strap joints at elevated temperatures.In the next part of the research, time factor was taken into account. By applying different load levels, the time-to-failure of the joints was monitored and analyzed. It was found that when temperature was close to or higher than Tg,the joint failure was time dependent. Based on the proposed temperature andtime-dependent material property models, the time dependence failure time of steel /CFRP double strap joints was well described.Next, the effects of long term exposure to UV and associated temperatures were investigated. It was shown that UV exposure does not influence the tensile strength of CFRP composites. The tensile strength of the adhesive reduced slightly while modulus showed significant increase after long term exposure.Although the tensile modulus of adhesive exposed to only thermal environment also increased, it is considerably less than that induced by UV exposure.The UV exposure also led to a decrease in joint strength but an increase in stiffness,caused by the temperature effect rather than the UV rays.The next stage of the research investigated the effects of sea water and moisture.It was shown that sea water appeared to reduce the joint strength and stiffness both by 20% after 1 year of exposure, and the joints exposed to combinations of temperature and humidity in the environmental chamber showed little decrease in joint strength and stiffness after 1000 h of exposure. A model was developed to predict the strength and stiffness degradation of the joints in sea-water and the results compared well with the experimental results.Finally, the effects of sustained load and curing were examined. It was found that the effects of sustained load were significant which could catastrophically cause joint failure when it was combined with cyclic temperature and humidity.Elevated curing of the steel /CFRP bonded joint helped to improve the mechanical performance of the joints at elevated temperatures and increased the time-to-failure of the joints. Partial safety factors proposed in design guidelines for FRP composites under environmental effects were used to evaluate the experimental results obtained, suggesting a very critical degradation of joint mechanical properties due to the environmental effects investigated in this study.

Download or read book Bond Characteristics and Environmental Durability of CFRP Materials for Strengthening Steel Bridges and Structures written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents the findings of a research program that was conducted in two parts to investigate the bond behavior and environmental durability of carbon fiber reinforced polymer (CFRP) materials for strengthening steel bridges and structures. The first part of the research consisted of an experimental and analytical research program to investigate the bond characteristics of CFRP lap-splice joints. The experimental program included a total of eight double-lap shear tests and ten steel beam tests. The main parameters considered include the geometric configuration of the plate ends, the length of the splice plates and the use of mechanical anchorage near the plate ends. A finite element analysis was conducted to determine the distribution of the stresses within the adhesive layer for different splice configurations. The findings indicate that the presence of the reverse tapered plate end reduced the magnitude of the peak stresses in the adhesive layer thereby increasing the tension strength of the splice joints. Increasing the splice length and installing additional mechanical anchorage did not enhance the strength of the joints. Based on the findings, a method is proposed to design lap-splice joints for implementation of the proposed CFRP system on longer-span flexural members. The second part of the research consisted of a total of 44 steel-CFRP double-lap shear tests to study the environmental durability of the proposed CFRP strengthening system. The specimens were exposed to accelerated corrosion conditions and subsequently loaded monotonically to failure. The additional use of a silane adhesion promoter or a glass fiber insulating layer, to enhance the bond durability, was also studied. The findings indicate that the presence of the glass fiber layer enhanced the initial bond strength of the system, while the use of a silane adhesion promoter was essential to ensure the durability of the system. The findings of this research program demonstrate that.

Download or read book Environmental Durability of Adhesively Bonded FRP Strengthened Steel Elements written by Milad Jabbari and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fibre reinforced polymer materials are regularly employed as reinforcing materials for structural elements. Carbon fibre reinforced polymers (CFRP) are particularly suited for strengthening of steel structural elements because of their lightweight nature and superior mechanical properties. Exposure to environmental stresses can weaken connections between bonded materials. This study was undertaken to further knowledge in relation to the performance of adhesively bonded CFRP-to-steel joints subjected to peel loading. Two epoxy adhesives were assessed with regard to their aging behaviour at different elevated temperature and hygrothermal conditioning scenarios and for various exposure periods. The performance of unaged specimens was also tested as a control. Adhesive coupon specimens and a modified mode I fracture test arrangement for use with dissimilar materials was employed. A total of 48 adhesive coupons were evaluated including 6 unaged adhesive coupons, 24 adhesive coupons subjected to elevated temperature and 18 adhesive coupons subjected to hygrothermal conditioning. In total, 54 CFRP-to-steel bonded specimens were evaluated including 6 unaged specimens, 24 specimens subjected to elevated temperature, 18 specimens subjected to hygrothermal conditioning and 6 specimens with different bond-line thickness. Exposure of coupons of both adhesives to elevated temperatures resulted in a considerable reduction in elastic moduli. Maximum strain of adhesive coupons fabricated with Adhesive A and B experienced an overall average increase of 30% and 39%, respectively, after exposure to elevated temperatures. The maximum failure load of fracture specimens manufactured with Adhesive A and B reduced up to 9% and 12%, respectively, after exposure to elevated temperature. Despite possessing higher strain energy release rate and higher load carrying capacity of fracture specimens manufactured with Adhesive B compared to Adhesive A, the bonding performance of Adhesive B is more affected by elevated temperature and this needs to be noted when using Adhesive B in areas with hot climates. Humid and wet conditioning caused up to 44% and 63% drop in elastic modulus, 31% and 55% reduction in tensile strength, and 32% and 44% increase in average in maximum strain of adhesive materials, respectively. Hygrothermal conditioning may cause the adhesion failure near to the edges of the adhesive joints. The load-carrying capacity of adhesive joints and strain energy release rate depend on the adhesive and hygrothermal environment, and can be degraded up to 15%. Reducing the bond-line thickness to less than 1 mm can result in a major reduction in load-carrying capacity and strain energy release rate of CFRP-to-steel bonded specimens. A nonlinear finite element analysis which employed a cohesive zone crack model was conducted and showed that the proposed modified experimental arrangement was dominated by mode I behaviour. Finite element analysis was also performed to simulate moisture diffusion through the bonding of CFRP-to-steel joint.

Download or read book Guide for the Design and Construction of Concrete Reinforced with Fiber Reinforced Polymer Bars written by ACI Committee 440 and published by . This book was released on 2003 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fiber reinforced plastic FRP Reinforcement for Concrete Structures written by Antonio Nanni and published by Elsevier Publishing Company. This book was released on 1993 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of fiber reinforced plastic (FRP) composites for prestressed and non-prestressed concrete reinforcement has developed into a technology with serious and substantial claims for the advancement of construction materials and methods. Research and development is now occurring worldwide. The 20 papers in this volume make a further contribution in advancing knowledge and acceptance of FRP composites for concrete reinforcement. The articles are divided into three parts. Part I introduces FRP reinforcement for concrete structures and describes general material properties and manufacturing meth.

Download or read book Maintenance Safety Risk Management and Life Cycle Performance of Bridges written by Nigel Powers and published by CRC Press. This book was released on 2018-07-04 with total page 5447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maintenance, Safety, Risk, Management and Life-Cycle Performance of Bridges contains lectures and papers presented at the Ninth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2018), held in Melbourne, Australia, 9-13 July 2018. This volume consists of a book of extended abstracts and a USB card containing the full papers of 393 contributions presented at IABMAS 2018, including the T.Y. Lin Lecture, 10 Keynote Lectures, and 382 technical papers from 40 countries. The contributions presented at IABMAS 2018 deal with the state of the art as well as emerging concepts and innovative applications related to the main aspects of bridge maintenance, safety, risk, management and life-cycle performance. Major topics include: new design methods, bridge codes, heavy vehicle and load models, bridge management systems, prediction of future traffic models, service life prediction, residual service life, sustainability and life-cycle assessments, maintenance strategies, bridge diagnostics, health monitoring, non-destructive testing, field testing, safety and serviceability, assessment and evaluation, damage identification, deterioration modelling, repair and retrofitting strategies, bridge reliability, fatigue and corrosion, extreme loads, advanced experimental simulations, and advanced computer simulations, among others. This volume provides both an up-to-date overview of the field of bridge engineering and significant contributions to the process of more rational decision-making on bridge maintenance, safety, risk, management and life-cycle performance of bridges for the purpose of enhancing the welfare of society. The Editors hope that these Proceedings will serve as a valuable reference to all concerned with bridge structure and infrastructure systems, including students, researchers and engineers from all areas of bridge engineering.

Download or read book Aging and Durability of FRP Composites and Nanocomposites written by Arya Uthaman and published by Elsevier. This book was released on 2024-02-21 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The usage of composites is a broad and growing area of scientific research, especially in developed and developing countries. These materials are used in a broad range of applications in both structural and civil engineering sectors. In many of these applications FRPs are exposed to one or more environmental influences, so they need to be designed to meet durability requirements to withstand even the harshest of environments. Aging and Durability of FRP Composites and Nanocomposites focuses on the latest developments in durability and long-term ageing studies of composite materials especially for those used in civil and structural engineering applications. The book will be a valuable reference resource for materials scientists and engineers who want to learn more about the long-term service life and durability behaviour of composites under different environmental conditions. - Discusses composites and polymer nanocomposites - Reviews different types of aging processes and degradation mechanisms in composites - Covers different types of accelerated aging tests - Presents theory, modeling, and simulation studies of aged composites and nanocomposites - Looks at recent trends and future possibilities

Download or read book FRP Strengthened Metallic Structures written by Xiao-Ling Zhao and published by CRC Press. This book was released on 2013-09-13 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: Repairing or strengthening failing metallic structures traditionally involves using bulky and heavy external steel plates that often pose their own problems. The plates are generally prone to corrosion and overall fatigue. Fiber-reinforced polymer (FRP), a composite material made of a polymer matrix reinforced with fibers, offers a great alternativ

Download or read book Bridge Maintenance Safety Management Life Cycle Sustainability and Innovations written by Hiroshi Yokota and published by CRC Press. This book was released on 2021-04-20 with total page 926 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations contains lectures and papers presented at the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), held in Sapporo, Hokkaido, Japan, April 11–15, 2021. This volume consists of a book of extended abstracts and a USB card containing the full papers of 571 contributions presented at IABMAS 2020, including the T.Y. Lin Lecture, 9 Keynote Lectures, and 561 technical papers from 40 countries. The contributions presented at IABMAS 2020 deal with the state of the art as well as emerging concepts and innovative applications related to the main aspects of maintenance, safety, management, life-cycle sustainability and technological innovations of bridges. Major topics include: advanced bridge design, construction and maintenance approaches, safety, reliability and risk evaluation, life-cycle management, life-cycle sustainability, standardization, analytical models, bridge management systems, service life prediction, maintenance and management strategies, structural health monitoring, non-destructive testing and field testing, safety, resilience, robustness and redundancy, durability enhancement, repair and rehabilitation, fatigue and corrosion, extreme loads, and application of information and computer technology and artificial intelligence for bridges, among others. This volume provides both an up-to-date overview of the field of bridge engineering and significant contributions to the process of making more rational decisions on maintenance, safety, management, life-cycle sustainability and technological innovations of bridges for the purpose of enhancing the welfare of society. The Editors hope that these Proceedings will serve as a valuable reference to all concerned with bridge structure and infrastructure systems, including engineers, researchers, academics and students from all areas of bridge engineering.

Download or read book Development of a Flexural Bond Strength Test to Determine Environmental Degradation of Carbon Fiber reinforced Polymer CFRP Composites Bonded to Concrete written by Amber Lee Gartner and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Testing will be done on epoxy and composite samples to determine the individual components effect in the beam specimen degradation. Flexural tests will continue to be performed on beams exposed for different periods to confirm the strength reduction trend with exposure time and temperature.

Download or read book Impact Behaviour of Fibre Reinforced Composite Materials and Structures written by S. R. Reid and published by Elsevier. This book was released on 2000-10-12 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study covers impact response, damage tolerance and failure of fibre-reinforced composite materials and structures. Materials development, analysis and prediction of structural behaviour and cost-effective design all have a bearing on the impact response of composites and this book brings together for the first time the most comprehensive and up-to-date research work from leading international experts. - State of the art analysis of impact response, damage tolerance and failure of FRC materials - Distinguished contributors provide expert analysis of the most recent materials and structures - Valuable tool for R&D engineers, materials scientists and designers

Download or read book American Environmentalism written by J. Michael Martinez and published by CRC Press. This book was released on 2013-06-20 with total page 1227 pages. Available in PDF, EPUB and Kindle. Book excerpt: Protecting the natural environment and promoting sustainability have become important objectives, but achieving such goals presents myriad challenges for even the most committed environmentalist. American Environmentalism: Philosophy, History, and Public Policy examines whether competing interests can be reconciled while developing consistent, coherent, effective public policy to regulate uses and protection of the natural environment without destroying the national economy. It then reviews a range of possible solutions. The book delves into key normative concepts that undergird American perspectives on nature by providing an overview of philosophical concepts found in the western intellectual tradition, the presuppositions inherent in neoclassical economics, and anthropocentric (human-centered) and biocentric (earth-centered) positions on sustainability. It traces the evolution of attitudes about nature from the time of the Ancient Greeks through Europeans in the Middle Ages and the Renaissance, the Enlightenment and the American Founders, the nineteenth and twentieth centuries, and up to the present. Building on this foundation, the author examines the political landscape as non-governmental organizations (NGOs), industry leaders, and government officials struggle to balance industrial development with environmental concerns. Outrageous claims, silly misrepresentations, bogus arguments, absurd contentions, and overblown prophesies of impending calamities are bandied about by many parties on all sides of the debate—industry spokespeople, elected representatives, unelected regulators, concerned citizens, and environmental NGOs alike. In lieu of descending into this morass, the author circumvents the silliness to explore the crucial issues through a more focused, disciplined approach. Rather than engage in acrimonious debate over minutiae, as so often occurs in the context of "green" claims, he recasts the issue in a way that provides a cohesive look at all sides. This effort may be quixotic, but how else to cut the Gordian knot?

Download or read book Defects and Damage in Composite Materials and Structures written by Rikard Benton Heslehurst and published by CRC Press. This book was released on 2014-04-21 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: The advantages of composite materials include a high specific strength and stiffness, formability, and a comparative resistance to fatigue cracking and corrosion. However, not forsaking these advantages, composite materials are prone to a wide range of defects and damage that can significantly reduce the residual strength and stiffness of a structure or result in unfavorable load paths. Emphasizing defect identification and restitution, Defects and Damage in Composite Materials and Structures explains how defects and damage in composite materials and structures impact composite component performance. Providing ready access to an extensive, descriptive list of defects and damage types, this must-have reference: Examines defect criticality in composite structures Recommends repair actions to restore structural integrity Discusses failure modes and mechanisms of composites due to defects Reviews NDI processes for finding and identifying defects in composite materials Relating defect detection methods to defect type, the author merges his experience in the field of in-service activities for composite airframe maintenance and repair with indispensable reports and articles on defects and damage in advanced composite materials from the last 50 years.

Download or read book Environmental Durability Evaluation of Externally Bonded Composites written by and published by . This book was released on 2004 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Fibre Reinforced Polymer FRP Composites for Structural Applications written by Jiping Bai and published by Elsevier. This book was released on 2013-09-30 with total page 929 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced fibre-reinforced polymer (FRP) composites have become essential materials for the building of new structures and for the repair of existing infrastructure. Advanced fibre-reinforced polymer (FRP) composites for structural applications provides an overview of different advanced FRP composites and the use of these materials in a variety of application areas.Part one introduces materials used in the creation of advanced FRP composites including polyester, vinylester and epoxy resins. Part two goes on to explore the processing and fabrication of advanced FRP composites and includes chapters on prepreg processing and filament winding processes. Part three highlights properties of advanced FRP composites and explores how performance can be managed and tested. Applications of advanced FRP composites, including bridge engineering, pipe rehabilitation in the oil and gas industry and sustainable energy production, are discussed in part four.With its distinguished editor and international team of expert contributors, Advanced fibre-reinforced polymer (FRP) composites for structural applications is a technical resource for researchers and engineers using advanced FRP composites, as well as professionals requiring an understanding of the production and properties of advanced FRP composites, and academics interested in this field. - Provides an overview of different advanced FRP composites and the use of these materials in a variety of application areas - Introduces materials used in the creation of advanced FRP composites including polyester, vinylester and epoxy resins - Explores the processing and fabrication of advanced FRP composites and includes chapters on prepreg processing and filament winding processes

Download or read book Durability Behavior of Fiber Reinforced Polymer and Steel Reinforced Polymer for Infrastructure Applications written by Wei Wang and published by . This book was released on 2017 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Crack development in reinforced concrete (RC) structures is common in elements such as bridge decks. However, these cracks can impose significant problems over time, because they allow chlorides from deicing chemicals to infiltrate concrete which will then corrode steel bars as RC structures are exposed to harsh weather. In the last decade, composite reinforcement systems are internally or externally applied to concrete structures instead of traditional steel reinforcing bars, or to strengthen concrete elements in flexure and shear. However, studies regarding the long-term durability performance of composite reinforcement systems is limited. Therefore, in order to popularize the application of these systems, it is necessary to study the long-term properties and behaviors of concrete members reinforced with composite materials. This study includes three topics: 1. Long-term durability of concrete panels reinforced with steel and glass reinforced polymer (GFRP). The main objective of this study is to investigate the mechanical properties of GFRP bars extracted from concrete panels after seven plus years of field exposure and examine any microscopic damage to the GFRP fiber and/or matrix resin; 2. Durability of concrete elements reinforced with Steel Reinforced Polymer (SRP). The key purpose of this study is to assess the bond behavior of SRP-to-concrete systems and provide durability study of SRP strengthening systems to supplement ACI 440; 3. Assessment of existing FRP bridge structures exposed to field conditioning. This study focuses on investigating the physical inspection for the existing FRP bridges in Rolla, MO and to characterize GFRP bars extracted from Southview Bridge (MO), Walker Bridge (MO), and Sierrita de la Cruz Bridge (TX) and surrounding concrete after several years of service"--Abstract, page iii.

Download or read book Nonconventional Concrete Technologies written by Committee on Nonconventional Concrete Technologies for Renewal of the Highway Infrastructure and published by National Academies Press. This book was released on 1997-04-08 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonconventional Concrete Technologies: Renewal of the Highway Infrastructure identifies research and development opportunities in innovative, nonconventional materials and processes that have the potential to accelerate the construction process, improve the durability of highway pavement and bridges, and enhance the serviceability and longevity of new construction under adverse conditions.