STRUKTUR BETON 1PERTEMUAN 2

DASAR PERENCANAAN BALOK BETON BERTULANG

Oleh :Arwan Apriyono

PROGRAM STUDI TEKNIK SIPIL JURUSAN TEKNIK FAKULTAS SAINS DAN TEKNIK UNSOED

TAHUN 2009

University of Michigan, TCAUP Structures II

Slide 2/26

Allowable Stress – WSD (ASD)

Actual loads used to determine stress Allowable stress reduced by factor of safety

Ultimate Strength – (LRFD) Loads increased depending on type load

g Factors: DL=1.4 LL=1.7 WL=1.3U=1.4DL+1.7LL

Strength reduced depending on type force

f Factors: flexure=0.9 shear=0.85 column=0.7

failureactual FSFf .).(

nu MM f

Examples:

WSD

Ultimate Strength

'1.0 cv ff

'45.0 cb ff

nu MM 9.0

nu VV 85.0

nu PP 70.0

Hal yang perlu diperhatikan pada perencanaan balok beton bertulang :

a. Kombinasi beban yang ada pada strukturb. Analisis struktur (Menghasilkan Mu dan Vu)c. Properties Beton dan Baja Tulangan (f’c dan fy)d. Konsep Perencanaan Balok Beton Bertulang

Item Perencanaan

Kombinasi Beban

Kombinasi Beban

Analisis Struktur

ANALISIS STATIS TERTENTU

ANALISIS STATIS TAKTENTU

DAPAT DIGUNAKAN BANTUAN SOFTWARE: AXIS, ANXIS, SAP, ETAB ETC

University of Michigan, TCAUP Structures II

Slide 7/26

Strength Measurement

Compressive strength› 12”x6” cylinder› 28 day moist cure› Ultimate (failure) strength

'cf

Photos: Source: Xb-70 (wikipedia)

Properties Beton

Properties Beton

Properties Beton

Properties Beton

Properties Beton

Properties Baja

Properties Baja

KURVA HUBUNGAN TEG-REG BAJA

Properties Baja

UKURAN BAJA TULANGAN

Konsep Perencanaan

University of Michigan, TCAUP Structures II

Slide 16/26

Failure Modes

No Reinforcing› Brittle failure

Reinforcing < balance› Steel yields before concrete fails› ductile failure

Reinforcing = balance› Concrete fails just as steel yields

Reinforcing > balance› Concrete fails before steel yields› Sudden failure

bdAs

yf200

min

yy

cbal ff

f870008700085.0 '

1

bal 75.0max

!h!SuddenDeatmax

Source: Polyparadigm (wikipedia)

Konsep Perencanaan

Konsep Perencanaan