scholarly journals Design for Deconstruction for Sustainable Composite Steel-Concrete Floor Systems

2018 ◽  
Author(s):  
Jerome F. Hajjar ◽  
Lizhong Wang ◽  
Mark D. Webster
Keyword(s):  
Raw Materials ◽  
Precast Concrete ◽  
Composite Beams ◽  
Flexural Behavior ◽  
Concrete Slabs ◽  
Steel Beams ◽  
Design Strategies ◽  
Composite Action ◽  
Floor Systems ◽  
Headed Stud

Conventional steel-concrete composite floor systems utilizing steel headed stud anchors and metal decks are cost-effective and widely used solutions for non-residential multi-story buildings, due in part to their enhanced strength and stiffness relative to non-composite systems. Because these systems use steel headed stud anchors welded onto steel flanges and encased in cast-in-place concrete slabs to achieve composite action, it is not possible to readily deconstruct and reuse the steel beams and concrete slabs. As the building industry is moving towards sustainability, there are clear needs for developing sustainable steel-concrete composite floor systems to facilitate material reuse, minimize consumption of raw materials, and reduce end-of-life building waste. This paper presents the behavior and design strategies for a sustainable steel-concrete composite floor system. In this system, deconstructable clamping connectors are utilized to attach precast concrete planks to steel beams to achieve composite action. The load-slip behavior of the clamping connectors was studied in pushout tests, and the test results showed that the clamping connectors possess similar shear strength to 19 mm diameter shear studs and much greater slip capacity. Four full-scale beam tests were performed to investigate the flexural behavior of the deconstructable composite beams under gravity loading and validate the connector behavior attained from the pushout tests. All the beams behaved in a ductile manner. The flexural strengths of the composite beam specimens closely match the strengths predicted for composite beams by the design provisions of the American Institute of Steel Construction (AISC).

Behaviour of headed studs in composite beams: push-out tests

1988 ◽  
Vol 15 (2) ◽  
pp. 240-253 ◽  
Author(s):  
B. S. Jayas ◽  
M. U. Hosain
Keyword(s):  
Composite Beams ◽  
Shear Capacity ◽  
Concrete Slabs ◽  
Steel Beam ◽  
Principal Mode ◽  
Pull Out ◽  
Factor Design ◽  
Headed Stud ◽  
Load And Resistance Factor ◽  
Push Out

This paper briefly summarizes the results of tests conducted on 18 full-size push-out specimens and 4 pull-out specimens. The objective of the project was to study the behaviour of headed studs in composite beams with ribbed metal decks perpendicular and parallel to the steel beam. The longitudinal spacing of the headed studs and the rib geometry of the metal decks were the principal experimental parameters.Five of the push-out specimens had solid concrete slabs, in five specimens the ribbed metal deck was placed parallel to the steel beam, and in the remaining eight specimens the metal deck was perpendicular to the steel beam. In most cases 38 mm deck and 16 × 76 studs were used.Test results obtained by the authors appear to indicate that with some exceptions the current Canadian Standards Association and Load and Resistance Factor Design codes are able to predict stud strength correctly for specimens with solid slabs and with parallel ribbed slabs only when failure occurs owing to stud shearing, i.e., when the studs are spaced sufficiently apart. It is recommended that these codes include a provision to check the possibility of concrete-related failures when the longitudinal stud spacing approaches or falls below six times the stud diameter for solid and parallel ribbed slabs.Stud pull-out was the principal mode of failure in the specimens with perpendicular ribbed metal decks. An equation recently proposed by Hawkins and Mitchell appears to underestimate the capacity for specimens with 38 mm deck. For specimens with 76 mm deck, their equation overestimates the stud capacity. The authors have proposed two separate but similar empirical equations for specimens with 38 and 76 mm deck. Key words: composite beam, headed stud, stud shear capacity, stud pull-out failure, minimum stud spacing, perpendicular deck, parallel deck.

Flexural behavior of hybrid precast concrete beams with H-steel beams at both ends

2010 ◽  
Vol 32 (9) ◽  
pp. 2940-2949 ◽  
Author(s):  
Keun-Hyeok Yang ◽  
Myoung-Ho Oh ◽  
Myeong-Han Kim ◽  
Ho-Chan Lee
Keyword(s):  
Concrete Beams ◽  
Precast Concrete ◽  
Flexural Behavior ◽  
Steel Beams

scholarly journals Effect of Angle Shear Connectors on the Behavior of Composite Concrete Steel Flexural Members Under Negative Moment

2018 ◽  
Vol 7 (4.20) ◽  
pp. 174
Author(s):  
Alaa M. Al-Khekany ◽  
Labeeb S. Al-Yassri ◽  
Munaf A. Al-Ramahee ◽  
Saeed Abdul-Abbas
Keyword(s):  
Bending Moment ◽  
Composite Beams ◽  
Point Load ◽  
Flexural Behavior ◽  
Experimental Program ◽  
Cross Sectional ◽  
Shear Connectors ◽  
Bond Interaction ◽  
Composite Section ◽  
Headed Stud

This research presents an experimental program to study the effect of using angle shear connectors instead of the headed stud on the flexural behavior of composite beams under negative bending moment (NBM). Both the angle and headed stud shear connectors used in this study have the same cross-sectional area. Five composite beams were casted and tested using three-point load configuration to ensure the NBM effect. Different parameters were included in this study such as the type of shear connector, bond interaction (partial and complete bond interaction) and arrangement of angle shear connectors. Two proposals method were suggested for angle setting in this study to investigate the structural behavior of the composite section. It has been found that, in the case of single angle shear connectors, the ultimate strength decreased by 4.12% compared with samples with the headed stud shear connectors. The direction of the angle setting has been shown to affect the flexural behavior of the composite section. 

Behaviour of perfobond rib shear connectors: push-out tests

1992 ◽  
Vol 19 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. R. Veldanda ◽  
M. U. Hosain
Keyword(s):  
Concrete Slab ◽  
Composite Beams ◽  
Steel Beams ◽  
Shear Connector ◽  
Reinforcing Bars ◽  
Longitudinal Splitting ◽  
Shear Connectors ◽  
Beam Shear ◽  
Headed Stud ◽  
Push Out

This paper summarizes the results of tests performed on 48 push-out specimens to investigate the feasibility of using perfobond rib type shear connectors in composite beams with ribbed metal decks placed parallel to the steel beams. The perfobond rib shear connector is a flat steel plate containing a number of holes. The results indicate that perfobond rib connectors can be effectively used in composite beams with ribbed metal decks placed parallel to the steel beams. An appreciable improvement in performance was observed in test specimens when additional reinforcing bars were passed through the perfobond rib holes. Shank shear was the principal mode of failure in specimens with headed studs. In specimens with perfobond rib, failure was triggered by the longitudinal splitting of the concrete slab, followed by the crushing of concrete in front of the perfobond rib. Key words: composite beam, shear connector, perfobond rib, headed stud, push-out test, metal deck.

scholarly journals Enhancement of Shear Transfer in Composite Deck with Mechanical Fasteners

2018 ◽  
Author(s):  
Christopher McComb ◽  
Fariborz Tehrani
Keyword(s):  
Concrete Slab ◽  
Steel Beams ◽  
Initial Stiffness ◽  
Additional Increase ◽  
Shear Transfer ◽  
Composite Action ◽  
Construction Methods ◽  
Reinforcing Fibers ◽  
Floor Systems ◽  
Steel Deck

Reinforced concrete construction and steel construction are two of the most common contemporary construction methods. Both methods make use of composite decks as floor systems and diaphragms. During the design of composite decks, the interaction between the steel deck and concrete slab is typically disregarded when calculating the strength of the composite di- aphragm due to lack of complete shear transfer, as existing practices such as stamping are not effective to provide substantial composite action. This conservative assumption essentially results in non-efficient use of material. This paper presents a method for ensuring shear transfer through the use of conventional sheet metal screws, driven through the corrugated steel deck and embedded in the fresh concrete. This method is proposed for use in the field between formed steel beams. Both experimental and analytical stud- ies support an increase in strength with the addition of embedded fasteners. Further, experimental results indicate an additional increase in strength with the addition of synthetic reinforcing fibers. The increase in strength with the addition of the fasteners is on the order of 100%. When fasteners are already in use, the addition of synthetic reinforcing fibers can increase strength on the order of 10%. The ultimate deflection of enhanced deck is comparable to deck tested without fasteners, but the initial stiffness of enhanced deck is much higher.

scholarly journals Development of Narrow Loop Joint for Precast Concrete Slabs with Fiber-Reinforced Mortar: Experimental Investigation of Material Properties and Flexural Behavior of Joint

2021 ◽  
Vol 11 (17) ◽  
pp. 8235
Author(s):  
Shuichi Fujikura ◽  
Minh Hai Nguyen ◽  
Shotaro Baba ◽  
Hiromi Fujiwara ◽  
Hisao Tategami ◽  
...  
Keyword(s):  
Concrete Slab ◽  
Precast Concrete ◽  
Highway Bridges ◽  
Flexural Behavior ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slab ◽  
Suitable Material ◽  
Girder Bridges ◽  
Steel Girder Bridges

In the replacement of the reinforced concrete slab in existing steel girder bridges, a loop joint is commonly used to join precast concrete slabs on site. However, a relatively wide joint is needed, and considerable time and effort are consumed to construct the joint due to the addition of transverse reinforcements to the joint on site. These disadvantages affect the progress of on-site construction and should be addressed, especially when this method is applied to highway bridges, where early traffic opening is necessary in many cases. This study proposes a narrow loop joint that has fiber-reinforced mortar without transverse reinforcements. Several material tests were conducted to determine a suitable material for the joint. A series of flexural loading tests of slabs was conducted to investigate the flexural behavior of the proposed loop joint with the selected material (polyvinyl alcohol (PVA) fibers). The results showed that the flexural capacity and deformation performance of the proposed joint with PVA fibers are equivalent to those of the conventional loop joint.

Structural behavior of alternative low floor height system using structural "tee," half precast concrete, and horizontal stud

2005 ◽  
Vol 32 (2) ◽  
pp. 329-338 ◽  
Author(s):  
Young K Ju ◽  
Sang-Dae Kim
Keyword(s):  
Composite Beam ◽  
Precast Concrete ◽  
Steel Structure ◽  
Monotonic Loading ◽  
Concrete Slabs ◽  
Steel Beams ◽  
Height System ◽  
Loading Tests ◽  
Beam Height ◽  
Storey Building

Conventional composite construction consisting of steel beams and concrete slabs has been widely used throughout the world. When compared with a concrete flat-slab structure, however, the reduced beam height is a significant problem and is particularly important in a city where land prices are higher because a height reduction of 15 cm per storey can lead to a 750 cm reduction in the total height for a 50 storey building (equivalent to two storeys). In this paper a newly developed composite beam, the technical, economical, and convenient (TEC) beam, is proposed and experimentally investigated using a series of monotonic loading tests. The results show that the capacity of the proposed system is in agreement with design code predictions, and the system demonstrates a reliable composite behavior between steel beam and concrete slab.Key words: composite beam, steel structure, monotonic loading, flexural capacity.

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