Anchorage of Ribbed Reinforcing Bars PDF Download

Author: Bent Steen Andreasen
Publisher:
ISBN: 9788777400179
Category :
Languages : en
Pages : 256

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Author: Bent Steen Andreasen
Publisher:
ISBN: 9788777400186
Category :
Languages : en
Pages : 70

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Author:
Publisher:
ISBN:
Category : Anchorage (Structural engineering)
Languages : en
Pages : 160

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Book Description
The use of a few large-diameter reinforcing bars for the construction of precast concrete bridge bents allows simplified construction by reducing the number of alignments to be made in the field. These bars are grouted into ducts in a precast concrete cap beam. In the proposed precast concrete substructure system, the grouted bars carry tensile forces across the joint between the column and cap beam. This joint is the yielding element in the structural system, and it is crucial to the performance of the structure that the bars yield before other failure mechanisms, including bond failure, occur. However, the cap beam is typically insufficient to anchor the bar, as the depth of the beam is substantially less than the American Association of State Highway and Transportation Officials (AASHTO) bridge code allows. For this project, 17 pullout tests were conducted to determine the bond characteristics and development length of large-diameter bars grouted into ducts. The bars tested ranged in size from #8 to #18. Pullout tests conducted with embedment lengths of at least six bar diameters yielded the reinforcing bar, while the test conducted with an embedment length of 14 bar diameters resulted in bar fracture. The tests and subsequent analysis showed that the bond of these grouted connections is significantly better than the bond of bars cast directly into concrete. The development lengths needed to fully anchor the bar are therefore within the depth available in the cap beam.

Author:
Publisher:
ISBN: 9788777400001
Category : Civil engineering
Languages : da
Pages : 25

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Author: Charles W. Atwater
Publisher:
ISBN:
Category : Hooks
Languages : en
Pages : 70

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Book Description

Author: fib - Fédération internationale du béton
Publisher: fib - Fédération internationale du béton
ISBN: 2883941122
Category : Technology & Engineering
Languages : en
Pages : 177

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Book Description
As part of the preparation for the fib Model Code for Concrete Structures 2010, task group 4.5 Bond Models undertook a major review of rules for bond and anchorage of reinforcement in the CEB-FIP Model Code 1990. This bulletin presents the outcome of that review, describes the rationale for the revisions and presents the evidence on which the revisions are based. The principle changes in MC2010 include raising the limit on concrete strength that may be used when determining bond resistance to 110MPa, introduction of a coefficient η4 to cater for different reinforcement Classes, and coverage of new construction materials including epoxy coated and headed bars. The format of design rules has been changed to permit more rational treatment of confinement from concrete cover and transverse reinforcement, the contribution of end hooks and bends for tension bars, and end bearing to compression laps. New guidance is provided covering a range of construction techniques and service environments and the influence of long term degradation. Analyses of various aspects of detailing on performance of laps and anchorages have resulted in discontinuation of the ‘proportion lapped’ factor α6, alterations to requirements of transverse reinforcement at laps, and have resolved inconsistencies in provisions for bundled bars between major national codes. Apparent inconsistencies in existing rules for lapped joints and anchorages and between the local bond/slip model and design rules are also resolved, thus allowing integration of application rules and modelling. Finally, the basis for an attempt to introduce simple detailing rules for laps and anchorages is described.

Author: fib Fédération internationale du béton
Publisher: fib Fédération internationale du béton
ISBN: 9782883940505
Category : Technology & Engineering
Languages : en
Pages : 448

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"In 1993, the CEB Commission 2 Material and Behavior Modelling established the Task Group 2.5 Bond Models. It's terms of reference were ... to write a state-of-art report concerning bond of reinforcement in concrete and later recommend how the knowledge could be applied in practice (Model Code like text proposal)... {This work} covers the first part ... the state-of-art report."--Pref.

Author: Antoine Makhlouf
Publisher:
ISBN:
Category : Reinforcing bars
Languages : en
Pages : 166

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Beams were designed to include two reinforcing bars in tension, spliced at the center of the span. The splice length was selected so that the bars would fail in bond, splitting the concrete cover in the splice region, before reaching the yield point. The bars were plain round Grade 60 bars with the splice length machined to simulate #6 (20 mm) deformed bars with parallel deformation pattern and different deformation geometries. No transverse reinforcement was provided in the splice region. The beam was loaded in positive bending and designed with constant moment region at the center of the beam. At each load increment, the deflection at the center of the beam was recorded and flexural cracks were marked and their widths measured. The variables were the bar rib face angle, rib spacing, and rib height. The results of this study were combined with results of previous investigations by Prof. Hamad to come up with recommendations concerning optimum rib geometries of deformed bars with superior bond-slip characteristics.

Author: B. S. Andreasen
Publisher:
ISBN:
Category :
Languages : en
Pages : 274

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Author: CRSI Staff & Members
Publisher:
ISBN: 9781943961191
Category :
Languages : en
Pages :

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Book Description
Features technical data on mechanical splices including load tests for Type 1 and Type 2 splices. Includes extensive tables of development and lap splice lengths for Grade 60 reinforcing bars with 3,000 to 10,000 psi concrete compressive strengths, and development and lap splice tables for epoxy-coated reinforcing bars, including development length tables. Also includes expanded information on headed bars.