Concrete dimension

Ram Series can dimension the steel necessary to add to the concrete in order to resist the calculated strengths. The dimension and checking is based on the EHE Spanish regulation. It is based in a point per point checking. In this way, any type of structural typology can be analyzed. To begin, choose:

Concrete->Concrete

Dimension of the plate over the support

To dimension the plate just over the support, select on point close to the support after pressing button Sel. In the window.

Check that you want to dimension in the x’ axe, typology type: plate and then press button Dimension .

Note : In theory, it would be necessary to select the point just over the support to dimension the section. In practice, it is better to select one point more separated, in order to have less strengths there, and accept a little of plasticity in the materials.

Ram Series gives one proposal for arming the section and the level of security that the proposed steel has:

To modify it press button transfer (the triangle pointing to right in the figure). The proposed steel is included as one steel set in the system.

Select the included steel set from the list and pick button Edit/Ren . Another option is just create a new steel set with button New . Then, change it as seen in the figure:

Press Ok and then, select the newly created steel set and press Check . To see the calculation made to justify this steel, select View Results

One report similar to this one will be viewed:

Elemento 540

Esfuerzos sobre la sección

Esfuerzo axil

Momento (Mx')

Cortante

-5.484kN/m

-73.0356kN·m/m

3.40121kN/m

Propiedades del elemento

Longitud

1m

Recubrimiento geom.

4cm

As,inf

3.93cm2

5φ10

As,sup

10.6cm2

2φ10,8φ12

Recubrimiento mec.

d'inf =4.5cm

d'sup =4.59cm

Tipo de armado

Placa

Se considera arm. compresión

Armadura transversal

At

At,min =8.33cm2 /m

1e2rφ8c/10cm

Sep. max: 14.7318cm

Coeficientes adicionales de seguridad

Armadura mínima longitudinal

1.90

Armadura longitudinal

1.07

Comprobación fisuración

1.19

Armadura transversal

1.21

Coeficiente global

1.07

Nota:Coeficiente mayor o igual a 1.0 indica seguridad en la estructura

Cálculo de recubrimientos geométricos (EHE 37.2.4)

Tipo de exposición: IIb

fck =25N/mm2

Control normal de ejecución

rnom =rmin +Δr=30+10=40mm

Comprobación sección 1

Cuantías geométricas mínimas (EHE 42.3.5)

Comprobación para placas.

As,inf = 3.92699cm2 > 50%·1.8/1000·Ac =2.07cm2

As,sup = 10.6186cm2 > 50%·1.8/1000·Ac =2.07cm2

CUMPLE

Limitación flexión (EHE 42.3.2)

As,sup ·fyd > 0.25·W/h·fcd

0.00106186·434.783 > 0.25·0.00881667/0.23·16.6667

461.678kN > 159.722kN

CUMPLE

Agotamiento frente a solicitaciones normales (EHE 42.1)

Se considera la armadura de compresión para el cálculo.

As,inf =3.93cm2   As,sup =10.6cm2

Posición x=0m;  Axil=-5.484kN   Momento=-73.0356kN·m CUMPLE

Fisuración por solicitaciones normales. Compresión (EHE 49.2.1)

N=-3.57977kN M=-47.6153kN·m => σc =12.176MPa

fck,120 =1.24·fck =1.24·25=31MPa

σc < 0.60fck,120

12.176MPa < 0.60·31=18.6MPa CUMPLE

Fisuración por tracción (EHE 49.2.3)

N=-3.57977kN M=-47.6153kN·m => σs =264.015MPa

fct,m =0.3*sqrt3 (fck 2 )=2.56496MPa

Mfis =b·h2 /6·fct,m =22.6144kN·m

σsr =Mfis /(0.8·d·As )=22614.4/(0.8·0.184148·0.00106186)=144.565Mpa

k1 =(ε12 )/(8ε1 )=(0.00175997+0)/(8·0.00175997)=0.125

Ac,eficaz =575cm2

sm =2c+0.2s+0.4k1 φAc,eficaz /As =2·40+0.2·100+0.4·0.125·12·575/10.6186=132.49mm

εsms /Es [1-k2srs )2 ]=0.00112218 > 0.4σs /Es

Clase de exposición IIb wmax =0.3mm

wk =1.7sm εsm < wmax

0.253mm < 0.3mm CUMPLE

Comprobación a cortante con armadura (EHE 44.2.3)

Agotamiento por compresión oblicua del alma (EHE 44.2.3.1)

Vrd =Vd =3.40121 kN (x=0.092074m)

Vu1 =0.30·fcd b0 d=0.30·16666.7·1·0.184148=920.74kN

Vrd < Vu1 CUMPLE

Agotamiento por tracción en el alma (EHE 44.2.3.2)

Vrd =Vd =3.40121kN (x=0.276222m)

Vcu =0.10ξ(100ρ1 fck )1/3 ·b0 d=0.10·2.04215(100·0.00576633·25)1/3 ·1000·184.148=91.524 kN

ξ=1+(200/d)1/2 =2.04215

ρ1 =As /(b0 d)=0.00576633 < 0.02

fy90,d =fyd < 400N/mm2   (EHE 40.2)

Vsu =A90 fy90,d 0.90d=0.00100531·4e+008·0.9·0.184148=66.6452 kN

Vrd < Vcu +Vsu

3.40121 kN < 158.169 kN CUMPLE

Disposiciones relativas a las armaduras (EHE 44.2.3.4)

Vrd <1/5Vu1

st < 0.8d;  st < 300mm

< ;   < CUMPLE

Cuantía mínima de armadura transversal (EHE 44.2.3.4)

A90 fy90,d > 0.02fcd b0

0.00100531·4e+008 > 0.02·1.66667e+007·1

402.124 kN > 333.333 kN CUMPLE

Limitación de fisuración por cortante (EHE 49.3)

(Vrd -3Vcu )/(A90 d)=-1767.08 MPa

st =100 mm < CUMPLE

Disposición mínima por armadura a compresión (EHE 42.3.1)

st < 15φmin

< 15·10=150 mm CUMPLE

φt > 1/4φmax ·st /15φmin

> 1/4·10·0.666667=1.66667 mm CUMPLE

Dimension of the support

To dimension the support, select on point close to the support after pressing button Sel. In the window.

The rest of the process is the same that the one of the shell.