Acceptance of Stay Cable Systems Using Prestressing Steels

Acceptance of Stay Cable Systems Using Prestressing Steels

Author: fib Fédération internationale du béton

Publisher: fib Fédération internationale du béton

Published: 2005-01-01

Total Pages: 98

ISBN-13: 9782883940703

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This fib Recommendation gives technical guidelines regarding design, testing, acceptance, installation, qualification, inspection and maintenance of stay cable systems using prestressing steels (strands, wires or bars) as tensile elements, which can be applied internationally. This Recommendation is applicable for cable-stayed bridges and other suspended structures such as roofs. It may also be used for hangers in arch structures and as suspension cables, as appropriate. This Recommendations has been formulated by an international working group comprising more than 20 experts from administrative authorities, universities, laboratories, owners, structural designers, suppliers of prestressing steels and stay cable suppliers. The text has been written to cover best construction practices around the world, and to provide material specifications that are considered to be the most advanced available at the time of preparing this text. For ease of use (for client, designer and cable supplier), the complex content has been arranged thematically according to the system components into chapters focusing on performance characteristics, requirements and acceptance criteria. Requirements and comments have been specified for all parties involved in design and construction in order to aim for a uniform and high quality and durability. The interfaces to the structural designer are highlighted. The essential subjects are: Design and detailing of stay cables including saddles and damping devices Durability requirements and corrosion protection systems Requirements for the materials Testing requirements for the stay cables Installation, tolerances, qualification of companies and personnel Inspection, maintenance and repair. This Recommendation does not cover the technology of stay cables whose tensile elements are ropes, locked-coil cables, etc. or which consist of composite materials. Nevertheless, in many cases the specified performance criteria may also be applicable to these systems, although numerical values given for the acceptance criteria may need to be adjusted. For these systems it has been difficult to provide multiple protective layers similar to those specified for stay cables made from prestressing steel and therefore, the quality of corrosion protection may not be equivalent. While extradosed cables have similarities with stay cables, generally agreed design and system acceptance criteria are not yet available and therefore, this type of cable is not covered.


Acceptance of cable systems using prestressing steels

Acceptance of cable systems using prestressing steels

Author: FIB – International Federation for Structural Concrete

Publisher: FIB - Féd. Int. du Béton

Published: 2019-03-01

Total Pages: 126

ISBN-13: 2883941297

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Cable-stayed structures have become increasingly popular over the last 30 years and have been used in all parts of the world. Modern cable-stayed bridges have a history of over 50-years and have been constructed with span lengths ranging from 15 m to over 1000 m. Many long span cable-stayed bridges have been built for railway and highway traffic applications. Stay cables have also been used on pedestrian structures, many of which are architecturally striking and have become landmark structures. There is growing use in building structures, particularly for cable-supported roofs. Most of the cable supported structures have been in the form of cable-stayed bridges; but in recent years, extradosed bridges have seen increased popularity among the designers. Led by the experience in Japan, more than 200 extradosed bridges have been constructed worldwide in the past 15 years. The first edition of these fib recommendations was published as fib Bulletin 30 in 2005 and was the first specification published by fib for stay cable systems. This new bulletin has been updated based on Bulletin 30 with the aim to reflect the current state of the art and encompass the latest knowledge in cable systems. In addition, it has been the aspiration of Commission 5 and Task Group 5.5 to harmonize the guidance in this updated bulletin with other stay cable recommendations from around the world, including those from Europe, Japan and the USA. This new bulletin is intended to supersede and replace fib Bulletin 30. It is recommended that it be used in lieu of fib Bulletin 30 for all future cable supported applications. The updated bulletin introduces several significant enhancements to the specifications: These recommendations are applicable to both stay cable and extradosed cable applications. In the past, there has been some debate over the boundary between cable-stayed and extradosed bridges. This bulletin presents a new continuous approach valid for both. A completely new testing requirement to assess the performance of cable systems under bending fatigue, including both anchorages and saddles, if applicable, has been added. Testing requirements for saddle systems have been reformulated. In addition to the bending fatigue test noted above, new testing procedures for stay cable saddles with isolated tensile elements are introduced. This includes tests for saddle axial fatigue, friction and tensile testing, and determination of the effective saddle friction coefficient. Expanded system qualification, including requirements for both stay cable and extradosed applications. Includes new provisions for MTE qualification and additional load transferring connection devices. Minimum number of tests is specified for each. A new in-situ damping measurement test has been added to verify the actual damping ratio of the damping devices installed. By testing on site, selected cables may be excited to vibrate without and with the damping devices so that the observed v vibration behaviour can be compared to the specified value. Other revisions have been made to reflect the current state of practice: Expanded quality control testing requirements Inclusion of epoxy-coated prestressing steel as a protection layer. Previous recommendations only considered zinc coatings. Specifications for epoxy coating material are given. Requirements for stainless steel components such as pipes, caps and plates Updated guidance for designing lightning protection systems Detailed recommendations for different levels of inspection of cable systems, including: initial, routine, detailed and exceptional inspections An updated list of references, relevant standards, and extended literature


Mechanobiology in Health and Disease

Mechanobiology in Health and Disease

Author: Stefaan Verbruggen

Publisher: Academic Press

Published: 2018-08-09

Total Pages: 530

ISBN-13: 0128129530

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Mechanobiology in Health and Disease brings together contributions from leading biologists, clinicians, physicists and engineers in one convenient volume, providing a unified source of information for researchers in this highly multidisciplinary area. Opening chapters provide essential background information on cell mechanotransduction and essential mechanobiology methods and techniques. Other sections focus on the study of mechanobiology in healthy systems, including bone, tendons, muscles, blood vessels, the heart and the skin, as well as mechanobiology studies of pregnancy. Final chapters address the nascent area of mechanobiology in disease, from the study of bone conditions, skin diseases and heart diseases to cancer. A discussion of future perspectives for research completes each chapter in the volume. This is a timely resource for both early-career and established researchers working on mechanobiology. - Provides an essential digest of primary research from many fields and disciplines in one convenient volume - Covers both experimental approaches and descriptions of mechanobiology problems from mathematical and numerical perspectives - Addresses the hot topic of mechanobiology in disease, a particularly dynamic field of frontier science


Kumba Africa

Kumba Africa

Author: Sampson Ejike Odum

Publisher: iUniverse

Published: 2020-11-03

Total Pages: 123

ISBN-13: 1663205043

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‘KUMBA AFRICA’, is a compilation of African Short Stories written as fiction by Sampson Ejike Odum, nostalgically taking our memory back several thousands of years ago in Africa, reminding us about our past heritage. It digs deep into the traditional life style of the Africans of old, their beliefs, their leadership, their courage, their culture, their wars, their defeat and their victories long before the emergence of the white man on the soil of Africa. As a talented writer of rich resource and superior creativity, armed with in-depth knowledge of different cultures and traditions in Africa, the Author throws light on the rich cultural heritage of the people of Africa when civilization was yet unknown to the people. The book reminds the readers that the Africans of old kept their pride and still enjoyed their own lives. They celebrated victories when wars were won, enjoyed their New yam festivals and villages engaged themselves in seasonal wrestling contest etc; Early morning during harmattan season, they gathered firewood and made fire inside their small huts to hit up their bodies from the chilling cold of the harmattan. That was the Africa of old we will always remember. In Africa today, the story have changed. The people now enjoy civilized cultures made possible by the influence of the white man through his scientific and technological process. Yet there are some uncivilized places in Africa whose people haven’t tested or felt the impact of civilization. These people still maintain their ancient traditions and culture. In everything, we believe that days when people paraded barefooted in Africa to the swarmp to tap palm wine and fetch firewood from there farms are almost fading away. The huts are now gradually been replaced with houses built of blocks and beautiful roofs. Thanks to modern civilization. Donkeys and camels are no longer used for carrying heavy loads for merchants. They are now been replaced by heavy trucks and lorries. African traditional methods of healing are now been substituted by hospitals. In all these, I will always love and remember Africa, the home of my birth and must respect her cultures and traditions as an AFRICAN AUTHOR.


Yvain

Yvain

Author: Chretien de Troyes

Publisher: Yale University Press

Published: 1987-09-10

Total Pages: 242

ISBN-13: 0300187580

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The twelfth-century French poet Chrétien de Troyes is a major figure in European literature. His courtly romances fathered the Arthurian tradition and influenced countless other poets in England as well as on the continent. Yet because of the difficulty of capturing his swift-moving style in translation, English-speaking audiences are largely unfamiliar with the pleasures of reading his poems. Now, for the first time, an experienced translator of medieval verse who is himself a poet provides a translation of Chrétien’s major poem, Yvain, in verse that fully and satisfyingly captures the movement, the sense, and the spirit of the Old French original. Yvain is a courtly romance with a moral tenor; it is ironic and sometimes bawdy; the poetry is crisp and vivid. In addition, the psychological and the socio-historical perceptions of the poem are of profound literary and historical importance, for it evokes the emotions and the values of a flourishing, vibrant medieval past.