PERILAKU DAN PENINGKATAN KAPASITAS BALOK TINGGI AKIBAT PERUBAHAN RASIO BENTANG GESER TERHADAP TINGGI EFEKTIF BALOK (a/d)
ABSTRACT: The advantage
of deep beam
is it has
a stiffness factor
higher than conventional
beam. Design of
deep beam-reinforced concrete
usually just consider
minimum reinforcement only,
for longitudinal reinforcement
and shear reinforcement because
deep beam is not designed to received main load but just for esthetic only.
Because of that reason, this
research is needed
to design reinforcement
on deep beam for carrying main
load so that
a premier failure
can be avoid. Twelve
(12) specimens are
used in this
research. The compressive
strength of the
deep-beams is 25
MPa simply supported with the
dimensions of (13x40x100) cm such as result from geometric scale 1: 4. The
tensile reinforcement is 4 Ø 10 mm
and the compressive
reinforcement is 2
Ø 10 mm.
The shear reinforcement
used is Ø 6
– 100
mm for each specimen. Longitudinal shear
reinforcement variations used without longitudinal shear reinforcement, 2 Ø 6
mm, 4 Ø 6 mm and 6
Ø 6 mm.
For each variations
used, there are 3 sample
tests. The sample
tests are done
by using two-point simetrical load and
span shear ratio
towards effective deep
beam (a/d) starting
from 0,6 ;
0,8 ; and 1.
Data of crack-load, ultimate-load, strain
of longitudinal reinforcement, strain
of shear reinforcement, strain
of longitudinal shear reinforcement and
displacement of beam on
point load is measured
for load increase with
interval load is
250 kg. The result of
the research shows
that span shear ratio
towards effective deep
beam (a/d) can establish
shear crack load capacity (Pcr) and ultimate load
capacity (Pu) of deep beam. Decreasing of span shear ratio towards effective
deep beam (a/d) caused load capacity of deep beam increase. Strain of
reinforcement was measured load capacity of deep beam, for Pcr and
Pu. Span shear
ratio towards effective beam depth
(a/d) is influence
load capacity of
deep beam. So that, increasing span
shear ratio towards
effective deep beam
(a/d) caused strain
of longitudinal reinforcement
and shear reinforcement decrease.
Span shear ratio towards effective deep beam (a/d) also measure behavior of
deep beam. At the shorter span shear
ratio towards effective
deep beam (a/d),
failure of deep
beam is shear-failure. At the
longer span shear ratio towards
effective deep beam (a/d), failure of deep beam is tension-failure.
Keywords: Longitudinal shear
reinforcement, shear capacity, span shear ratio
Penulis: Ninik Catur Endah
Yuliati
Kode Jurnal: jptsipildd070003
