PERILAKU BALOK BERLUBANG EMPAT PERSEGI PANJANG DAN LINGKARAN PADA JOINT BALOK KOLOM EKSTERIOR AKIBAT BEBAN GEMPA (Behavior of Reinforced Concrete Beam Having Rectangular and Circular-Shaped Openings at Exterior Reinforce
| Main Author: | Perpustakaan UGM, i-lib |
|---|---|
| Format: | Article NonPeerReviewed |
| Terbitan: |
[Yogyakarta] : Universitas Gadjah Mada
, 2005
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| Subjects: | |
| Online Access: |
https://repository.ugm.ac.id/23816/ http://i-lib.ugm.ac.id/jurnal/download.php?dataId=6777 |
Daftar Isi:
- ABSTRACT Structural engineers are frequently confronted with the problem of providing passage for utility ducts and pipes to accommodate essential services such as waste water plumbing, heating, air-conditioning, telephones, and electricity. There is a growing trend in providing services ducts through openings in the floor beams. However, openings in the web of a reinforced concrete beam induces high stress concentration at the corner of the opening, may reduce beam stiffness and may alter beam behavior to a more complex one. Therefore, while providing an opening, the effects on ultimate strength and service load behaviour Of the beam must be properly accounted for in design. This study investigated the effect of rectangular and circular-shaped openings on the behavior of exterior reinforced concrete beam-column joints subjected to earthquake-type loading. Five exterior reinforced concrete beam-column joints were constructed and tested. All five specimens had 275 mm x 275 mm square columns with a total height of 2 m. The main beam had a 175 x 325 mm cross section and extended 1.5 m away from the inner face of the column. The slab was 60 mm thick and 945 mm wide. The column-to-beam flexural strength ratio, ---Mn,k1 Mn,b, was approximately L3 (greater than 1.2, Ehsani and Wight (1985)) and the maximum joint shear stress was 1.712 MPa (less than 1.0 Mpa, Ehsani and Wight (1985)). An axial compressive load, equal to 0.15f,A5 , was applied to the column prior to the application of cyclic lateral load, which was applied pseudo-statically using a collar located at the end of the beam. Results of the test showed that the predominant modes of failure occured in 2d away from the inner face of the column. The presence of web openings did not push the failure away from plastic hinge. Degradation of the first crack load subjected to negative moment was 13.48% and degradation of the first crack load subjected to positive moment was 37.6% compared to the reference specimen. For the same areas of the openings, degradation of the first crack load subjected to positive moment, achieved by rectangular-shaped openings, was 1.5 and 2 times to that of circular-shaped openings. Web openings reduced energy dissipation too. The degradation of hysteretic energy of specimens with rectangular-shaped openings was 1.14 and 1.04 times to that of circular-shaped openings. Key words : exterior reinforced concrete beam-column joint, openings, cyclic loads.