The document provides calculations to determine the required reinforcement for a concrete floor slab supported on three points A, B, and C. 1. The slab span is calculated as 4.8 meters and the slab thickness as 20 cm. 2. The dead and live loads are determined to calculate the uniform load of 12.8 kN/m2. 3. Moment calculations are done at the supports and middle to determine the required steel reinforcement. The calculations follow design code requirements and consider parameters such as concrete strength, steel yield strength, and reinforcement ratios to adequately reinforce the slab for bending and shear stresses.

1. STRUKTUR
BETON I
V.A
V.B
V.C/
V.D
V.E

2. DIK : SUATU PLAT LANTAI TERLETAK DIATAS TIGA TUMPUAN A,B dan CPLAT
DIBEBANI BEBAN MATI (DL)/FINISHING = 0,5 kN/m² dan BEBAN HIDUP (LL) = 4 kN/m²
(Gbr) DATA PERHITUNGN : f’c = 25 Mpa (250 Kg/Cm²)
f’y = 400 Mpa (4.000 Kg/Cm²).
DIMINTA HITUNG : a. Pembesian Plat
PENYELESAIAN
:
= L/24 = 4800/24 = 200 mm diambil = 20 Cm
L = 4.560 + 2 x ½ 240 = 4.800 mm
1. Tentukan Lebar bentang
2. Tentukan tebal plat
24
0
24
0
4.560
h
GAMBAR PLAT
B
A
24
0
4.560

3. Wu= 1,2 x WD + 1,6 WL
WD = Berat sendiri Plat = 0,20 x 24 kN/m³ = 4,8 kN/m²
WD = Berat Finishing lantai = 0,5 kN/m²
JUMLAH WD = 5,3 kN/m²
Wu= 1,2 x 5,3 + 1,6 x 4 = 12,8 kN/m² ( 1.280 kg/m²)
3. HITUNG BEBAN
MA = MC = 1/24 x Wu x L²
MA = MC = 1/24 x 12,8 x (4,8)² = 12,3 kNm (1.230 kgm)
4. HITUNG MOMEN TUMPUAN
5. HITUNG M0MEN LAPANGAN
M lap AB = 1/11 x Wu x L²
Mlap AB= 1/11 x 12,8 x (4,8)² = 26,8 kNm (2.680 kgm)
MB = 1/9 x Wu x L²
MB = 1/9 x 12,8 x (4,8)² = 32,8 kNm (3.280 kgm)

4. Penutup beton Tabel = 20 mm = 2 Cm
diameter tulangan Ǿ = 12 mm = 1,2 Cm
6. Hitung Tulangan
d = h - a - 1/2 Ǿ = 200 - 20 - 1/2 x12 = 174 mm
Mu
bx d²
12,3
1,0 x (0,174 )²
= 406 kN/m² LIHAT TABEL SNI
7. MOMEN JEPIT TAK TERDUGA (MA = MC)
MA = MC = 12,3 kNm
Menurur Tabel di Interpolasi
400 = 0,0013
406 = ρ
500 = 0,0016
6
100 0,0003 6/100 x 0,0003 + 0,0013 = 0,0013
As = 0,0013 x1,0 x 0,174 x = 226 mm² ( 2,26Cm²)
PAKAI BESI Ǿ 8 – 200 mm = 251 mm² > 226 mm²

5. 8. MOMEN LAPANGAN BENTANG (MLapAB = Mlap BC)= 26,8 kNm
Mu
bx d²
26,8
1,0 x (0,174 )²
= 885 kN/m²
Menurur Tabel di Interpolasi
800 = 0,0026
885 = ρ
900 = 0,0029
85
100 0,0003 85/100 x 0,0003 + 0,0026 = 0,0029
ρ = 0,0029
ρ = 0,0029
ρmin = 0,0018
ρmak = 0,0203
Lihat Tabel 7
Lihat Tabel 8
ρmin < ρ< ρmak
As = ρ x b xd
As = 0,0029 x1,0 x 0,174 x = 505 mm² ( 5,05 Cm²)
PAKAI BESI Ǿ 10 – 250 mm = 515 mm² > 505 mm²

6. Tulangan Pembagi menurut SKSNI T15 – 1991-03 Pasal 3.16.12
= 400 Mpa : As =
As = = 360 mm (3,6 Cm²)
0,18 𝑥1000 𝑥 200
100
9. MOMEN TUMPUAN (MB = 32,8 kNm)
Mu
bx d²
32,8
1,0 x (0,174 )²
= 1.083 kN/m²
1.000 = 0,0032
1.083 = ρ
1.100 = 0,0036
83
100 0,0004 83/100 x 0,0004 + 0,0032 = 0,0035
ρ = 0,0035
As = 0,0035 x1,0 x 0,174 x = 609 mm² ( 6,1 Cm²)
PAKAI BESI Ǿ 10 – 125 mm = 628 mm² > 609 mm²

7. 24
0
24
0
4.560
h
B
A
24
0
4.560

9. TABEL 8
PROSENTASE TULANGAN MAKSIMUM ρ max
fy MPa
f'c Mpa(Kg/Cm²)
( Kg/Cm²
)
15 (150) 20 (200) 25 (250) 30 (300) 35 (350)
240
(2.400)
0.0242 0.0323 0.0404 0.0484 0.0538
400
(4.000)
0.0122 0.0163 0.0203 0.0244 0.0271

10. TABEL 6
TABEL NILAI -NILAI ρ min TIORITIS
fy MPa
( Kg/Cm² ) f'c Mpa(Kg/Cm²)
15 (150) 20 (200) 25 (250) 30 (300) 35 (350)
240
(2.400)
0.0025 0.0029 0.0032
0.0035 0.0038
400
(4.000)
0.0015 0.0017 0.0019
0.0021 0.0023

11. TABEL 7
TULANGAN MINIMUM YANG DISYARATAKAN ρ min
SELURUH fy = 250 MPa fy = 400 MPa
MUTU BETON =. 2.500 Kg/Cm² . = 4.000 Kg/Cm²
Balok dan Plat
Umumnya
0.0058 0.0035
Alternatif 4/3 ρ an 4/3 ρ an
Plat 0.0025 0.0018

12. TABEL PEMBESIAN BALOK DAN KOLOM

13. TABEL PEMBESIAN PLAT PER
METER PLAT