Design of Spandrel Beams

Klein, Gary

doi:10.15554/pcij.09011986.76.124

Cited by 14 publications

(8 citation statements)

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“…The procedure recommended by Zia and Hsu was not validated by full-scale tests of slender spandrels, as used in the field, until the investigations of Raths (1984) and the experimental work of Klein (1986). The findings of both Raths and Klein confirmed the findings published in Cleland's 1984 dissertation at the University of Virginia.…”

Section: Previous Studiesmentioning

confidence: 84%

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Development of a Rational Design Methodology for Precast Slender Spandrel Beams

Lucier¹,

Walter²,

Rizkalla³

et al. 2010

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The use of open web reinforcement for torsion and shear reinforcement in slender spandrel beams has been suggested by the precast concrete industry as an alternative to the traditional closed stirrups mandated by ACI 318-08. Investigations of slender precast spandrel beams by Raths (1984), Klein (1986), Logan (2007), and others have indicated that such closed stirrups may not be necessary for these slender, non-compact sections. The proposal of eliminating closed stirrups is very appealing to the precast industry because closed stirrups tend to significantly increase production costs. This report documents an extensive experimental and analytical research program sponsored by the Precast Prestressed Concrete Institute and conducted at North Carolina State University. The objective of the research was to develop a rational design procedure for precast slender spandrel beams. Specifically, the research aimed to simplify the detailing requirements for the end regions of precast slender spandrel beams. Such regions are often congested with heavy reinforcing cages when designed with current procedures.

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Section: Previous Studiesmentioning

confidence: 84%

“…The requirements for attachment of the ledge the web are given in PCI 4.5.4 and are based on a study of ledge-to-web attachment by Klein (1986). The transverse forces acting on a free body of a beam ledge are shown in Figure 2-12.…”

Section: Ledge-to-web Attachmentmentioning

confidence: 99%

Development of a Rational Design Methodology for Precast Slender Spandrel Beams

Lucier¹,

Walter²,

Rizkalla³

et al. 2010

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“…In addition, all four specimens passed the 1-hour ACI re-sistent with one another and were in agreement with what would typically be expected for a slender spandrel subjected to eccentric ledge loading. 5 Inner face cracking patterns were classically diagonal, refl ecting the additive nature of the principal tensile stresses caused by shear and torsion on the ledge side of the L-shaped spandrel. On the outer spandrel faces, where principal tensile stresses from shear and torsion tend to negate one another, fl exural cracking was primarily observed.…”

Section: Test Resultsmentioning

confidence: 99%

“…For many years, spandrels have been designed according to the general procedure originally proposed by Zia and McGee (1974) 1 and later by the modifi ed method introduced by Hsu (1978 and). 2,3 The design procedure was developed based on the results of laboratory testing of small, Raths (1984) 4 and Klein (1986) 5 revealed that the behavior of spandrels is signifi cantly affected by their support conditions. A signifi cant plate-bending effect was observed in the web of the slender spandrel.…”

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confidence: 99%

Precast Concrete, L-Shaped Spandrels Revisited: Full-Scale Tests

Lucier¹,

Rizkalla²,

Zia³

et al. 2007

pcij

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This paper presents the results from full-scale testing conducted at North Carolina State University on four precast, prestressed concrete L-shaped spandrels. The four L-shaped spandrels were each loaded through 12-ft-long (3.7 m), prestressed double tees that rested on the spandrel ledge at one end and on an independent support at the other. None of the beams were constructed with closed stirrups of mild-steel reinforcement. Rather, different arrangements of transverse L-shaped bars, welded-wire reinforcement, and longitudinal bars were provided to resist the shear and torsion induced in the spandrels. Shear and torsion forces were created by the double-tee reaction forces that were loaded eccentrically to the spandrels. The transverse and longitudinal reinforcement resisted the combined effects of vertical shear and out-ofplane bending of the web and satisfi ed the minimum vertical hanger reinforcement requirement for ledge-to-web attachment. All beams sustained loads well in excess of their factored design loads. Eliminating the need for closed reinforcement in slender spandrels would be of signifi cant benefi t to the precast concrete industry. This design approach would enhance the constructability of slender members, which could increase plant productivity and reduce overall costs. The paper presents the behavior of all four spandrels at various limit states, including their crack patterns and modes of failure. Researchers used these test results to better understand the fundamental mechanism developed in the L-shaped spandrels to resist shear and torsion.

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“…[4] punching shear design provisions might be overestimating the punching shear capacity of spandrel beam ledges. Raths also developed two design procedures for calculating the hanging reinforcement used later by Klein(1986) [5].…”

Section: Failure Of the Overall Torsion Equilibrium Tensionmentioning

confidence: 99%

Numerical Investigation of the Performance of Ledge Beams Considering the Contribution of Inner Stirrups to Support External Loads

Elhady¹,

Mostafa²,

Ghallab³

2020

IRJIET

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Reinforced concrete L-shaped beams are frequently used in the precast concrete industry specially in bridges construction to support a series of deck beams. The spandrel acts as a hanger for the ledge part, hence hanging reinforcement is used in the spandrel for this action. It was supposed that the outer vertical stirrups' branches are the main hanging elements for the ledge part; however, adding internal vertical branches contribute in hanging the ledge part. The perception that the outer vertical stirrups' branches solely are the main hanging elements and the neglection of the effect of inner stirrups' branches in hanging action can become questionable as it leads to using a great amount of outer reinforcement which leads to nesting of this part and increasing the fabrication cost of the beam. Therefore, a need exists to evaluate the contribution of the inner stirrups with the hanging steel reinforcement. This study aims to numerically model the performance of ledge beams taking into consideration distribution and amount of inner stirrups reinforcement, eccentricity of acting load on the capacity and performance of ledge beam.

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Design of Spandrel Beams

Cited by 14 publications

References 0 publications

Development of a Rational Design Methodology for Precast Slender Spandrel Beams

Development of a Rational Design Methodology for Precast Slender Spandrel Beams

Precast Concrete, L-Shaped Spandrels Revisited: Full-Scale Tests

Numerical Investigation of the Performance of Ledge Beams Considering the Contribution of Inner Stirrups to Support External Loads

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