Download or read book Calibration of Bond Durability Factor for Externally Bonded CFRP Systems in Concrete Structures written by Jovan Tatar and published by . This book was released on 2013 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Use of carbon fiber-reinforced polymer (CFRP) composites in civil infrastructure has shown an increase in the past two decades. Externally bonded CFRP materials (wet-layup and laminate) have found their application in repair of damaged concrete structures, particularly bridges. Lack of understanding and confidence in the long-term performance of externally bonded FRP systems in concrete structures still inhibits the use of FRP composites to repair bridges. The most significant issue with externally bonded FRP composites is their susceptibility to degradation when exposed to moisture. One method to gage this sensitivity to moisture is to accelerate the effect of the moisture by exposing the material to high heat and moisture. This research utilized small-beam specimens to study FRP-concrete bond performance when subjected to accelerated conditioning environments (immersion in water and exposure to high humidity at elevated temperatures). Small beams with bonded CFRP reinforcement were conditioned and then tested to failure under three-point bending. The bond strength index was determined by dividing the average conditioned strength by the average control strength.

Download or read book ACI 440 2R 17 Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures written by ACI Committee 440 and published by . This book was released on 2017-04-27 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Durability of Carbon Fiber Reinforced Polymer CFRP Repair strengthening Concrete Beams written by Jiangang Deng and published by ProQuest. This book was released on 2008 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon fiber-reinforced polymers (CFRP) have been widely used as externally epoxy-bonded reinforcement for repair and retrofit of existing concrete structures. As the use of CFRP in construction increases, it is essential to consider the long term behavior. In this study, concrete specimens with externally bonded CFRP composite systems were exposed to various accelerated ageing environments: different elevated temperature water immersion, varying relative humidity exposure, real-time solar exposure, pressurized hygrothermal exposure, and fatigue loading. Three-point loading test and direct tension test were used to evaluate the flexural and tensile strength of CFRP specimens. This research recommends that the durability strength reduction factor be defined as the ratio of the flexural strength of a test specimen after exposure for 60 days at 60C to the strength of a control specimen at the initiation of exposure. Test specimens, exposure environments, testing procedures, and field application environments are selected to assure uniform reporting, testing and application of durability strength reduction factors. Two exposure environments are recommended for design, wet and air. Water can diffuse through concrete and accumulate on the epoxy/concrete interface in a wet environment and is the default condition for design. An air environment precludes water accumulation but requires engineering design and validation to guarantee compliance. The resulting durability strength reduction factor may be used to (a) calculate the reduced strength for environmental exposure, (b) qualify a specific CFRP system, (c) compare durability reduction factors to those provided by system suppliers, and (d) confirm compliance with project specifications.

Download or read book Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures written by ACI Committee 440 and published by . This book was released on 2002 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Externally Bonded FRP Reinforcement for RC Structures written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2001-01-01 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: In December 1996, the then CEB established a Task Group with the main objective to elaborate design guidelines for the use of FRP reinforcement in accordance with the design format of the CEB-FIP Model Code and Eurocode2. With the merger of CEB and FIP into fib in 1998, this Task Group became fib TG 9.3 FRP Reinforcement for concrete structures in Commission 9 Reinforcing and Prestressing Materials and Systems. The Task Group consists of about 60 members, representing most European universities, research institutes and industrial companies working in the field of advanced composite reinforcement for concrete structures, as well as corresponding members from Canada, Japan and USA. Meetings are held twice a year and on the research level its work is supported by the EU TMR (European Union Training and Mobility of Researchers) Network "ConFibreCrete”. The work of fib TG 9.3 is performed by five working parties (WP): Material Testing and Characterization (MT&C) Reinforced Concrete (RC) Prestressed Concrete (PC) Externally Bonded Reinforcement (EBR) Marketing and Applications (M&A) This technical report constitutes the work conducted as of to date by the EBR party. This bulletin gives detailed design guidelines on the use of FRP EBR, the practical execution and the quality control, based on the current expertise and state-of-the-art knowledge of the task group members. It is regarded as a progress report since it is not the aim of this report to cover all aspects of RC strengthening with composites. Instead, it focuses on those aspects that form the majority of the design problems. several of the topics presented are subject of ongoing research and development, and the details of some modelling approaches may be subject to future revisions. as knowledge in this field is advancing rapidly, the work of the EBR WP will continue. Inspite of this limit in scope, considerable effort has been made to present a bulletin that is today’s state-of-art in the area of strengthening of concrete structures by means of externally bonded FRP reinforcement.

Download or read book Rehabilitation of Concrete Structures with Fiber Reinforced Polymer written by Riadh Al-Mahaidi and published by Butterworth-Heinemann. This book was released on 2018-11-12 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rehabilitation of Concrete Structures with Fiber Reinforced Polymer is a complete guide to the use of FRP in flexural, shear and axial strengthening of concrete structures. Through worked design examples, the authors guide readers through the details of usage, including anchorage systems, different materials and methods of repairing concrete structures using these techniques. Topics include the usage of FRP in concrete structure repair, concrete structural deterioration and rehabilitation, methods of structural rehabilitation and strengthening, a review of the design basis for FRP systems, including strengthening limits, fire endurance, and environmental considerations. In addition, readers will find sections on the strengthening of members under flexural stress, including failure modes, design procedures, examples and anchorage detailing, and sections on shear and torsion stress, axial strengthening, the installation of FRP systems, and strengthening against extreme loads, such as earthquakes and fire, amongst other important topics. - Presents worked design examples covering flexural, shear, and axial strengthening - Includes complete coverage of FRP in Concrete Repair - Explores the most recent guidelines (ACI440.2, 2017; AS5100.8, 2017 and Concrete society technical report no. 55, 2012)

Download or read book Durability of Carbon Fibre Reinforced Polymer Concrete Bond Under Sustained Load in Harsh Environment written by Basim M. Mahdi Abbas and published by . This book was released on 2010 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon Fibre Reinforced Polymer (CFRP) has great potential in civil engineering applications. It is used extensively in extending the structural capacity or service life of aging structures. CFRP is one of the best alternatives to traditional retrofitting materials. It has a very high strength-to-weight ratio with good resistance to environmental effects. Together with the fibres, the adhesive and the substratum are the main constituents of the CFRP bonding systems. However, with high quality plated CFRP, the latter two components introduce some doubts about the system's performance. There is therefore a crucial research need to investigate the effects of environmental exposures on the system under loading conditions. In the present work, the effects of extreme environmental exposures on the bond properties between externally-applied carbon fibre reinforced polymer (CFRP) and concrete were investigated. Preloaded CFRP-concrete samples at various load intensities were exposed to several conditions. The exposure conditions were temperature cycles with humidity, constant temperature at increasing humidity, soaking in saline water at different temperatures, and different salt concentrations. Finally, actual extreme marine site environments including direct exposure to sunlight were explored. The change of bond characteristics between the externally-applied CFRP and concrete due to permanent loads, aging, and exposure conditions were used as measures of degradation effects. Other properties such as the development of the strain field with load, bond-slip relationships, detection of cracking intensity and location were evaluated using photogrammetry and acoustic emission techniques. Tensile pull-out and torsional shear strength were also explored. A Neural Network method was implemented for the prediction of bond strength and the expected failure of preloaded samples in different environments. The objective of the study was to understand the behaviour of preloaded concrete-CFRP bonding systems and evaluate the changes in the bond properties due to combinations of factors in harsh environments. It was found that high temperature and the combined aggressive site conditions were the major factors leading to sample failure.

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 Design Procedures for the Use of Composites in Strengthening of Reinforced Concrete Structures written by Carlo Pellegrino and published by Springer. This book was released on 2015-08-25 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book analyses the current knowledge on structural behaviour of RC elements and structures strengthened with composite materials (experimental, analytical and numerical approaches for EBR and NSM), particularly in relation to the above topics, and the comparison of the predictions of the current available codes/recommendations/guidelines with selected experimental results. The book shows possible critical issues (discrepancies, lacunae, relevant parameters, test procedures, etc.) related to current code predictions or to evaluate their reliability, in order to develop more uniform methods and basic rules for design and control of FRP strengthened RC structures. General problems/critical issues are clarified on the basis of the actual experiences, detect discrepancies in existing codes, lacunae in knowledge and, concerning these identified subjects, provide proposals for improvements. The book will help to contribute to promote and consolidate a more qualified and conscious approach towards rehabilitation and strengthening existing RC structures with composites and their possible monitoring.

Download or read book FRP Composites in Civil Engineering CICE 2004 written by R. Seracino and published by CRC Press. This book was released on 2004-12-15 with total page 1005 pages. Available in PDF, EPUB and Kindle. Book excerpt: The range of fibre-reinforced polymer (FRP) applications in new construction, and in the retrofitting of existing civil engineering infrastructure, is continuing to grow worldwide. Furthermore, this progress is being matched by advancing research into all aspects of analysis and design. The Second International Conference on FRP Composites in

Download or read book Numerical Analysis of Debonding Mechanisms of Externally Bonded FRP Reinforcement in RC Beams written by Michael Cohen and published by . This book was released on 2018 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is an urgent need to develop economic and efficient methods to repair and strengthen existing reinforced concrete structures. This demand is motivated by several factors including the aging of concrete structures, the desire to upgrade design standards, and the exposure to severe environmental effects. A particular problem confronting engineers in repairing deteriorated structures is the rehabilitation of reinforced concrete elements. Conventionally, steel plates were utilized to restore and enhance the tensile strength of damaged concrete members. Despite the effectiveness of this practice in terms of improving the structural capacity, it is still considered disadvantageous due to the excessive weight of steel and its susceptibility to corrosion in moist environments. The application of fibre reinforced polymer (FRP) to existing reinforced concrete structures has gained the interest of many researchers in the last few decades. These materials are superior to steel when it comes to comparing the resistance to electrochemical corrosion, strength-to-weight ratio, ease of handling, fatigue resistance, and availability in any length or shape. However, there is still a serious concern regarding the effect of premature debonding of the FRP plates before reaching the desired strength or ductility. This debonding can initiate from the ends of the plate or can be induced by intermediate cracks in the concrete member. Although the end-plate debonding and peeling mechanisms have been studied extensively, there is still a significant lack of data for FRP-strengthened beams in which intermediate crack-induced debonding is the dominant failure mode. On the other hand, the interfacial bond capacity between the concrete and the FRP composite has not been thoroughly investigated. Whereas, there is still need to study the effect of some of the mechanical and physical parameters on the bond strength of FRP-Concrete interface. Moreover, researchers have also shown a keen interest in simulating flexural cracks in concrete beams, and examine their effect on the debonding mechanisms of FRP materials. However, more realistic approach is needed to model cracks and account for their growth. In this study, a three-dimensional nonlinear finite element model was developed for simulating the flexural behaviour of RC beams externally bonded with FRP systems. The ABAQUS/CAE software version 6.14-2 was used for this purpose. This numerical analysis was performed based on a comprehensive experimental program conducted by Brena et al. (2003). The simulated RC beams were categorized in two groups: Control Beams (without fibre) and CFRP Beams (with carbon fibre reinforced polymer). During the process of constructing the CFRP beam models, two distinct procedures were followed to simulate the interface between the concrete and the externally attached FRP laminates. Perfect bond was assumed in the first approach, and a Cohesive Zone Model (CZM) was adopted in the second approach. In the latter, cohesive surface technique was implemented in the ABAQUS model through the use of traction-separation law. Despite the lack of quantitative evaluation in the literature as no similar techniques was attempted by others, the results of this numerical analysis were only compared with experimental findings, and the proposed models were found to be reliable. A parametric study was performed to investigate the influence of various parameters on the flexural capacity of the proposed beam model, and the debonding behaviour of the externally attached FRP laminate. This analysis was conducted by either changing the mechanical properties of some of the constitutive materials (e.g. concrete and reinforcing steel), or altering the geometrical and mechanical properties of the FRP reinforcement. It was then found that the effect of internal steel reinforcement ratio has the most impact on beam ultimate capacity. While changing the FRP bond length beyond a certain value bears no effect on beam strength. Moreover, the numerical model was modified to review the effect of intermediate crack spacings on the overall beam performance. A discrete crack approach was adopted to replicate crack propagation throughout the body of the beam. This technique has shown an approximately 30% improvement in the prediction capacity of this model when compared to a similar specimen in which smeared crack approach is used. The results of this analysis showed that the debonding behaviour of FRP laminates is largely influenced by crack spacing. In addition, the results have also indicated that the initiation of FRP micro-debonding was prolonged as crack spacings were decreased. This response can be attributed to the abrasion effect within the FRP-Concrete interface. Finally, this numerical analysis provides a relatively reliable guidance on the application and the mitigation of externally bonded FRP reinforcement in concrete beams. The predictive capability of the proposed FE models ensures their suitableness for further investigations of FRP effectiveness in civil engineering field.

Download or read book Ultra High Performance Concrete UHPC written by Ekkehard Fehling and published by John Wiley & Sons. This book was released on 2015-04-20 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selected chapters from the German concrete yearbook are now being published in the new English "Beton-Kalender Series" for the benefit of an international audience. Since it was founded in 1906, the Ernst & Sohn "Beton-Kalender" has been supporting developments in reinforced and prestressed concrete. The aim was to publish a yearbook to reflect progress in "ferro-concrete" structures until - as the book's first editor, Fritz von Emperger (1862-1942), expressed it - the "tempestuous development" in this form of construction came to an end. However, the "Beton-Kalender" quickly became the chosen work of reference for civil and structural engineers, and apart from the years 1945-1950 has been published annually ever since. Ultra high performance concrete (UHPC) is a milestone in concrete technology and application. It permits the construction of both more slender and more durable concrete structures with a prolonged service life and thus improved sustainability. This book is a comprehensive overview of UHPC - from the principles behind its production and its mechanical properties to design and detailing aspects. The focus is on the material behaviour of steel fibre-reinforced UHPC. Numerical modelling and detailing of the connections with reinforced concrete elements are featured as well. Numerous examples worldwide - bridges, columns, facades and roofs - are the basis for additional explanations about the benefits of UHPC and how it helps to realise several architectural requirements. The authors are extensively involved in the testing, design, construction and monitoring of UHPC structures. What they provide here is therefore a unique synopsis of the state of the art with a view to practical applications.

Download or read book Design Guidelines for Durability of Bonded CFRP Repair strengthening of Concrete Beams written by and published by . This book was released on 2010 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research provides a methodology for evaluation of durability related strength loss of bonded carbon fiber reinforced polymer (CFRP) systems applied to concrete beams. The report addresses test methods to establish a durability strength reduction factor, identification of corresponding field exposure conditions affecting durability, and suggestions for the application of the durability strength reduction factor for design of field applications. The durability strength reduction factor is a measure of the loss in strength over time due to environmental exposure. It is defined as the ratio of the flexural strength of a 4 in. x 4 in. x 14 in. concrete beam reinforced with CFRP exposed at 140°F and submerged in water or 100% relative humidity for 60 days to the flexural strength of a control specimen. The resulting durability strength reduction factor may be used to evaluate CFRP system performance. Two field environments are suggested: Wet and Air. In a Wet environment water accumulates at the bond surface. This is the default condition and corresponds to test results in submerged water at 140°F for 60 days. An Air environment allows drying between wetting episodes so water cannot accumulate on the bond surface. This condition corresponds to test results in 100% relative humidity at 140°F for 60 days.

Download or read book FRP Composites for Reinforced and Prestressed Concrete Structures written by Perumalsamy Balaguru and published by CRC Press. This book was released on 2008-11-05 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: High strength fibre composites (FRPs) have been used with civil structures since the 1980s, mostly in the repair, strengthening and retrofitting of concrete structures. This has attracted considerable research, and the industry has expanded exponentially in the last decade. Design guidelines have been developed by professional organizations in a nu

Download or read book Bonded Repair and Retrofit of Concrete Structures Using FRP Composites written by Amir Mirmiran and published by Transportation Research Board. This book was released on 2004 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: The global response to COVID-19 has demonstrated the importance of vigilance and preparedness for infectious diseases, particularly influenza. There is a need for more effective influenza vaccines and modern manufacturing technologies that are adaptable and scalable to meet demand during a pandemic. The rapid development of COVID-19 vaccines has demonstrated what is possible with extensive data sharing, researchers who have the necessary resources and novel technologies to conduct and apply their research, rolling review by regulators, and public-private partnerships. As demonstrated throughout the response to COVID-19, the process of research and development of novel vaccines can be significantly optimized when stakeholders are provided with the resources and technologies needed to support their response. Vaccine Research and Development to Advance Pandemic and Seasonal Influenza Preparedness and Response focuses on how to leverage the knowledge gained from the COVID-19 pandemic to optimize vaccine research and development (R&D) to support the prevention and control of seasonal and pandemic influenza. The committee's findings address four dimensions of vaccine R&D: (1) basic and translational science, (2) clinical science, (3) manufacturing science, and (4) regulatory science.

Download or read book Textile Reinforced Cement Composites written by Jan Wastiels and published by MDPI. This book was released on 2020-03-05 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Issue presents the latest advances in the field of Textile-Reinforced Cement Composites, including Textile-Reinforced Concrete (TRC), Textile-Reinforced Mortar (TRM), Fabric-Reinforced Cementitious Matrix (FRCM), etc. These composite materials distinguish themselves from other fibre-reinforced concrete materials by their strain-hardening behaviour under tensile loading. This Special Issue is composed of 14 papers covering new insights in structural and material engineering. The papers include investigations on the level of the fibre reinforcement system as well as on the level of the composites, investigating their impact and fatigue behaviour, durability and fire behaviour. Both the strengthening of existing structures and the development of new structural systems such as lightweight sandwich systems are presented, and analysis and design methods are discussed. This Special Issue demonstrates the broadness and intensity of the ongoing advancements in the field of Textile-Reinforced Cement composites and the importance of several future research directions.

Download or read book Failure Distress and Repair of Concrete Structures written by Norb Delatte and published by Elsevier. This book was released on 2009-10-26 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding and recognising failure mechanisms in concrete is a fundamental pre-requisite to determining the type of repair, or whether a repair is feasible. This title provides a review of concrete deterioration and damage, as well as looking at the problem of defects in concrete. It also discusses condition assessment and repair techniques.Part one discusses failure mechanisms in concrete and covers topics such as causes and mechanisms of deterioration in reinforced concrete, types of damage in concrete structures, types and causes of cracking and condition assessment of concrete structures. Part two reviews the repair of concrete structures with coverage of themes such as standards and guidelines for repairing concrete structures, methods of crack repair, repair materials, bonded concrete overlays, repairing and retrofitting concrete structures with fiber-reinforced polymers, patching deteriorated concrete structures and durability of repaired concrete.With its distinguished editor and international team of contributors, Failure and repair of concrete structures is a standard reference for civil engineers, architects and anyone working in the construction sector, as well as those concerned with ensuring the safety of concrete structures. - Provides a review of concrete deterioration and damage - Discusses condition assessment and repair techniques, standards and guidelines