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Concrete pressure

In addition to DIN 18218, other international methods use different parameters for calculating the concrete pressure. The main calculation methods

are featured below together with their main factors. The factors are designated on the basis of DIN 18218. Here it only states the calculation methods for

standard concrete; special conditions have to be observed for concrete with special properties.

1. CIRIA report 108 (United Kingdom)

Concrete pressure is calculated accor-ding to the CIRIA report 108 as follows:

or

whichever is smaller.

This calculation is based on the fol-lowing parameters: ■ �b ➔ raw density of the concrete

[kN/m³]■ vb ➔ pour rate of the concrete

[m/h]■ h ➔ pour height [m]

■ k1 ➔ cross section coefficient k1= 1,0 for walls

1,5 for columns (if both edge lengths are smaller than 2,0 m, the cross sections are designated to as columns)

■ k2 ➔ additive coefficient k2= 0,30 for normal concrete

0,45 for concrete with setting retarder

■ kT ➔ temperature coefficient kT= with T ➔ concrete

temperature [°C]

2. ACI 347R (USA):

According to ACI the concrete pressure is calculated according to the cross section form, differentiating between ranges of concreting speed. The calculations include:■ the cross section form■ the pour rate■ the concrete temperature■ and the pour height

The raw weight of the concrete is taken to be 2400 kg/m3.

For columns the concrete pressure is

taken to be:

The limits of concrete pressure for col-umns are defi ned as follows:pmin = 28,74 kN/m² pmax = 143,7 kN/m² or 23,5 * h (whichever is smaller)

For walls we differentiate between ranges of pour rate

■ vb < 2,14 m/h:The same formula is used as for columns

■ 2,14 < vb < 3 m/h:

■ vb > 3 m/h:pb = 23,5 * h

The concrete pressure limit values for walls are defi ned as follows: pmin = 28,74 kN/m² pmax = 95,8 kN/m² or 23,5 * h(whichever is smaller)

785 * Vb

17,78 + Tpb = 7,19 +

115517,78 + T

pb = 7,19 + + 244 * Vb

17,78 + T

Sewage plant, Karlsruhe-Durlach;

Dyckerhoff & Widmann AG, Karlsruhe

Flat silo, Süderbrarup; Max Giese, Büdelsdorf

pb = γb * (k1 * vb + k2 * kT * h-k1 * vb)

pb = γb * h

36 7 + 16( )

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