Penentuan Ketebalan Slab dan Parameter Perancangan Konkrit

A. Menetukan Tebal Slab ( PCA Method ACI 360R-10)

h_rencana = 25cm

= 10 inch

K = 300 kg/cm²

fc' = 24.9 mpa

= 3611 psi

ks = 12000 kn/m³

= 44 Ib/in³

= 1 ( Single Wheel )

S = 125 cm

= 49 in

Sd = 50cm

= 20

= 225

= 50.58 kips

FS = 2

Ac = 62500 mm²

= 96.88 in²

Ac_eff = 98in²

= 0.71 (Input Faktor Koreksi)

= -

Pac = 51 kips

fr=9√fc'= 540.86

ft_allow = fr/FS = 270.43

ft = ft_allow/Pac = 5.3

h_min = 9

h_min = 23

h_rencana > h_min (OK)

B. Diketahui Data Parameter Perencana Sebagai Berikut:

= 4 %

= 27 %

h = 25 cm

Lp = 10 m

M = 2400 kg/m³

g = 9.81 m/detik²

fc' (MPa) = 24.9 MPa

fc' (kg/cm2) = 300 kg/cm²

fy (kg/cm2) = 4200 kg/cm²

fs = 240 MPa

Ec = 257210 kg/cm²

Es = 2100000 kg/cm²

n = 8

(𝜇) = 1.8

fcf = 40.66 kg/cm²

fct = 20.33 kg/cm²

εs = 0.0004

b = 1000 mm

Koefisien Gesek Antara Slab dan Pondasi Bawah Kuat Tarik Langsung Beton, fcf = 3.13*K(fc')^0.5 Kuat Tarik Langsung Beton, fcf = ( 0.4 - 0.5* fcf) Koefisien Susut Beton, εs = 0,0004

Ditinjau Lebar, b Kuat Tekan Beton Tegangan Leleh Baja

Kuat Tarik Ijin Baja, Fs = 240 Mpa atau 0.6*fy Modulus Elastisitas Beton, Ec = 14850√ fc' Modulus Elastisitas Beton, Es = 2100000 Angka Ekivalen, n = Es/Ec

CBR Efektif Tebal Slab Lebar Slab Berat Jenis Beton Gravitasi Kuat Tekan Beton Tebal Slab Minimum

CBR Tanah Dasar Faktor Beban Equivalent Beban Sumbu yang Dipakai Modulus Keruntuhan Lentur Beton Tegangan Ijin Beton,

Tegangan Slab/ 1000 Ib Beban Sumbu Beban Sumbu

Safety Factor

Area Kontak Roda ( 1 Roda) Area Efektif Kontak Roda ( 1 Roda) Tipe Sumbu

Jarak Antar Roda Jarak Antar Roda Ganda Tebal Slab Rencana Mutu Beton

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C. Kontrol Kuat Geser Pons (Punching Shear)

fv = 0,33√fc' = 1.65 MPa

ɸ = 0.6

FK = 2

P = 112.5 kN

Pu = FK * P = 225 kN

a = 250

mm

b = 750

mm

L1 = 750

mm

L2 = 1250

mm

Av = 2 * (L1+L2) * h = 1000000

mm²

Pn = Av * fv = 1647

Kn

ɸ * Pn = 988

Kn

ɸ * Pn > Pu

(OK)

Sumber : Perencanaan Perkerasan Jalan Beton (Pd T-14-2003) D. Tulangan Arah Melintang/Memanjang

As perlu = μ* Lp * M * g * h

= 220.73 mm

²

/m

2 * fs

As min = 0.0018*b*h

= 450 mm

²

/m

As pakai

= 450 mm

²

/m

Digunakan Tulangan

D 13 - 275

Luas Tulangan Terpasang, As pasang :

As Pasang = π /4 * D² b/s

= 482.663 mm

²

/m

As

_Pasang

> As

_Pakai (OK)

2 * fs Faktor Reduuksi Kuat Geser Pons Faktor Beban Ultimit

Beban Roda Kendaraan Beban Roda Kendaraan Ultimit Kuat Geser Pons yang Disyaratkan