Formwork - Ciria Report 108 Concrete Pressure On

| | CIRIA 108 | ACI 347 (USA) | EN 12812 (Europe) | |-------------|----------------|--------------------|-------------------------| | Base formula | P_max = C1*(R/T) + C2 | P_max = C_w × C_c × (7.2 + 785R/(T+17.8)) | P_max = F + (R/(T+1)) × K | | Temperature | Explicit (°C) | Explicit (°C) | Explicit (°C) | | Slump influence | Coefficients for 0–50mm, 50–100mm, >100mm | C_c factor (0.5 to 1.2) | Built into K factor | | Rate limit | No strict cap, but pressure limited to hydrostatic | R ≤ 2.1 m/h for formula; above that, hydrostatic | R limited based on form class | | Minimum pressure | Yes (C2 term) | Yes (7.2 factor) | Yes (F term) |

The key takeaway:

The report proposes that concrete pressure follows a hydrostatic distribution (increasing with depth) until it reaches a maximum value ( Pmaxcap P sub m a x end-sub ciria report 108 concrete pressure on formwork

An empirical model to predict fresh concrete lateral pressure | | CIRIA 108 | ACI 347 (USA)