Studi Eksperimental Perilaku Siklis Flat Sab Beton Mutu Sangat Tinggi
DOI:
https://doi.org/10.5614/jts.2014.21.2.5Keywords:
Beton mutu sangat tinggi, Beban lateral siklis, Kekuatan, Kekakuan, Rasio daktilitas perpindahanAbstract
Abstrak. Makalah ini menampilkan hasil penelitian eksperimental terhadap 3 buah benda uji struktur flat slab beton mutu sangat tinggi dengan campuran beton bubuk reaktif dibawah kombinasi beban gravitasi dan beban lateral siklis. Pengujian dilakukan dengan sistem sub assemblage hubungan pelat dan kolom dari struktur flat slab. Benda uji terdiri dari pelat dengan rasio tulangan tarik relatif rendah (0,65%) dan relatif tinggi (1,8%) yang diaplikasikan untuk bentang pelat 3,00 m sedangkan untuk pelat dengan bentang 2,00 m rasio tulangan yang dipakai hanya 1,8%. Beban gravitasi sebesar 8,45 kN/m2 diaplikasikan konstan, sedangkan beban lateral siklis diberikan dalam bentuk displacement control. Pembebanan siklis dilakukan melebihi ketentuan drift ACI 374.1-05 yaitu sampaidengan drift 5,00%. Pada drift 5%, perilaku non linear struktur menunjukkan respon histeresis yang daktail tanpa mengalami penurunan kekuatan yang signifikan baik untuk rasio tulangan tinggi maupun rendah. Meskipun demikian, penurunan kekakuan masih terjadi. Pengaruh rasio tulangan tarik lebih signifikan dibanding bentang pelat terhadap respon kekuatan dan kekakuan pelat terutama pada fase inelastis. Pelat bentang 3,0 m dengan rasio tulangan tarik rendah mempunyai rasio daktilitas perpindahan paling tinggi sedangkan pelat dengan bentang 3,0 m dengan rasio tulangan tarik tinggi mempunyai rasio daktilitas perpindahan paling rendah dibanding yang lain.
Abstract. This paper presents the result of the experimental study on three very high strength concrete flat slab structures constructed with reactive powder concrete under combined gravity and cyclic lateral loads. The tests were conducted on slab-column connection sub assemblages of the flat slab structure. Two specimens had slab span of 3.00 m with relatively low and high tension steel reinforcement ratios of 0.65% and 1.8%, respectively. The other specimen had slab span of 2.00 m with tension steel reinforcoment ratio of 1.8%. The specimens were subjected to constant gravity load of 8.45 kN/m2 and the lateral cyclic load using displacement control close to 5% drift ratio. The drift was set up larger than as required in ACI 374.1-05. At 5% drift, nonlinear behavior of the structures showed ductile hysteresis responses without a significant decrease in strength both for lower and higher tension steel reinforcement ratio. However, a stiffness degradation still occurred for all specimens. Effect of tension steel reinforcement ratio was more significant than that of slab span on stiffness and strength responses particularly at inelastic ranges. Slab with span of 3.00 m and low tension steel reinforcement ratio showed the largest displacement ductility ratio while the slab with same span but higher tension steel reinforcement ratio resulted the lowest displacement ductility ratio compared to the other specimens.
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