Constructability and Detailing of RC Coupling Beams
By: Subramanian, N
.
Publisher: Thane ACC LTD 2021Edition: Vol.95(8), August.Description: 45-55p.Subject(s): Civil EngineeringOnline resources: Click here
In:
Indian Concrete Journal - ICJSummary: Coupled shear walls of multi-storey reinforced concrete buildings have been used in the past in earthquake zones. However, conventionally reinforced concrete coupling beams with length to depth ratio less than 4.0 were found to have deficient performance, especially during earthquake loading. Based on extensive experimental research, researchers have found that detailing of coupling beams using inclined reinforcement are more effective and perform better with adequate ductility. But such a detailing resulted in two constructability problems: (1) Two groups of diagonal reinforcement have to be provided with closely spaced ties, and (2) These diagonal bars have to be anchored in the adjacent walls, with 1.5 times the development length. ACI 318 (2019) suggested an alternate detailing option, where transverse reinforcement is placed around the beam cross section to provide confinement and suppress buckling, and no transverse reinforcement directly around the diagonal bar bundles. Such an option should also be provided in IS: 13920 (2016) for easy constructability. Various other alternate reinforcement details involving diagonal reinforcement, which are bent at the beam ends inside the coupling beam have also been proposed. The use of HPFRC with low volume fractions of fibres, can not only reduce the amount of steel used, but also reduce labour by simplifying the placement of reinforcement and accelerate construction schedule of these coupling beams.
| Item type | Current location | Call number | Status | Date due | Barcode | Item holds |
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Articles Abstract Database
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School of Engineering & Technology (PG) Archieval Section | Not for loan | 2021-2022672 |
Coupled shear walls of multi-storey reinforced concrete buildings have been used in the past in earthquake zones. However, conventionally reinforced concrete coupling beams with length to depth ratio less than 4.0 were found to have deficient performance, especially during earthquake loading. Based on extensive experimental research, researchers have found that detailing of coupling beams using inclined reinforcement are more effective and perform better with adequate ductility. But such a detailing resulted in two constructability problems: (1) Two groups of diagonal reinforcement have to be provided with closely spaced ties, and (2) These diagonal bars have to be anchored in the adjacent walls, with 1.5 times the development length. ACI 318 (2019) suggested an alternate detailing option, where transverse reinforcement is placed around the beam cross section to provide confinement and suppress buckling, and no transverse reinforcement directly around the diagonal bar bundles. Such an option should also be provided in IS: 13920 (2016) for easy constructability. Various other alternate reinforcement details involving diagonal reinforcement, which are bent at the beam ends inside the coupling beam have also been proposed. The use of HPFRC with low volume fractions of fibres, can not only reduce the amount of steel used, but also reduce labour by simplifying the placement of reinforcement and accelerate construction schedule of these coupling beams.
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