Momen
Pada saat pengecoran topping HCS diberi tumpuan sementara ditengah bentang
Qd2 2.44 kN m
1 −
⋅ ⋅
= Qd2
Qtop Qtam
+ =
Mdx x 3
16 Qd2
⋅ Lsl
⋅ x
⋅ 1
2 Qd2
⋅ x
2 ⋅
− =
Mdx 0.5 Lsl ⋅
2.745 −
kN m ⋅
⋅ =
Mcorpek Mdx 0.5 Lsl
⋅ −
=
negatif Pada saat tumpuan sementara dilepas
P 5
8 Qtop
⋅ Lsl
⋅ =
P 5.4 kN
⋅ =
Mprop 1
4 P
⋅ Lsl
⋅ =
Mprop 8.1 kN m
⋅ ⋅
= Mll
1 14
Qll ⋅
Lsl 2
⋅ =
Mll 7.714 kN m
⋅ ⋅
= Msdl
1 14
Qsdl ⋅
Lsl 2
⋅ =
Msdl 2.571 kN m
⋅ ⋅
= Mts
Mslb Mcorpek
− Mprop
+ Mll
+ Msdl
+ =
Mts 26.765 kN m
⋅ ⋅
= Mu
1.2Mslb 1.2Mcorpek
− 1.2Mprop
+ 1.2 Msdl
⋅ +
1.6Mll +
= Mu
35.203 kN m ⋅
⋅ =
Jadi banyaknya tendon
n 5
= Aps
141.372 mm 2
⋅ =
Luas Total Prestress
Aps n A1
⋅ =
Hasilnya :
Pi Aps fpi
⋅ =
Pi 137.837 kN
⋅ =
5. Check Tegangan
Peff fpeff Aps
⋅ =
Peff 110.27 kN
⋅ =
fpi 975 Mpa
⋅ =
Pi fpi Aps
⋅ =
Pi 137.837 kN
⋅ =
a. Pada saat transfer HCS saja:
σ a1l
Pi −
Ac Pi e
⋅ St
+ =
Fti 1.161 Mpa
⋅ =
≤
σ a1l
0.576 Mpa ⋅
= σ
b1l Pi
− Ac
Pi e ⋅
Sb −
=
≤
Fci 12.948
− Mpa
⋅ =
σ b1l
3.252 −
Mpa ⋅
=
b. Pada saat setelah losses
σ a1l
Peff −
Ac Peff e
⋅ St
+ Mslb
St −
= Fc
14.94 −
Mpa ⋅
=
≤
σ a1l
1.47 −
Mpa ⋅
= Ft
2.881 Mpa ⋅
= σ
b1l Peff
− Ac
Peff e ⋅
Sb −
Mslb Sb
+ =
≤
65
σ b1l
0.671 −
Mpa ⋅
=
Tegangan setelah topping terpasang
σ a2l
σ a1l
Mcorpek St
+ =
Ft 2.881 Mpa
⋅ =
≤
σ a2l
0.994 −
Mpa ⋅
= Fc
14.94 −
Mpa ⋅
= σ
b2l σ
b1l Mcorpek
Sb −
=
≤
σ b2l
1.147 −
Mpa ⋅
=
Tegangan setelah prop dilepaskan Sebagai pelat komposit
σ a3l
σ a2l
Mprop h Cbk
− ⋅
I ck −
= σ
a3l 1.461
− Mpa
⋅ =
Fc 14.94
− Mpa
⋅ =
≤
σ b3l
σ b2l
Mprop Sbk
+ =
σ b3l
0.107 −
Mpa ⋅
= Ft
2.881 Mpa ⋅
=
≤ c. Pada saat beban layan bekerja Sebagai pelat komposit
σ a4l
σ a3l
Mll Msdl
+ h
Cbk −
I ck ⋅
− =
σ a4l
2.054 −
Mpa ⋅
=
≤
Fc 14.94
− Mpa
⋅ =
σ b4l
σ b3l
Mll Sbk
+ Msdl
Sbk +
= σ
b4l 1.213 Mpa
⋅ =
Ft 2.881 Mpa
⋅ =
≤
Tegangan_beton_Saat_Layan MEMENUHI
=
6. Check Kapasitas Momen
Dw 6 mm
⋅ =
Diameter Tulangan Pratekan
Dw Dia
=
Diameter tulangan
Ds 6 mm
⋅ =
As1 1
4 π
⋅ Ds
2 ⋅
= As1
28.274 mm 2
⋅ =
Luas per tulangan Banyaknya tul. tekan
nc =
Asc 0 mm
2 ⋅
=
Luas Total tul. tekan
Asc nc As1
⋅ =
Banyaknya tul. tarik
np =
Ast 0 mm
2 ⋅
=
Luas Total tul. tarik
Ast np As1
⋅ =
Selimut Beton
dc 20 mm
⋅ =
Lengan Tulangan Pratekan
dp Ct
e +
= dp
180 mm ⋅
= d
221 mm ⋅
=
Lengan Tulangan Non Pratekan
d hsl
dc −
Dw −
0.5 Ds ⋅
− =
fpe Peff
Aps =
Tegangan Tul. Pratekan Efektif ≥
fpe 780 Mpa
⋅ =
0.5 fpu ⋅
812.5 Mpa ⋅
=
maka : Nilai
untuk p : 66
fpy fpu
0.9 =
γ p
0.2 8
=