Vibration/compaction: Internal vibration can increase lateral pressure locally and transiently due to fluidisation; external vibration of formwork may also alter pressures.
By trusting the CIRIA 108 calculation, they saved over £2 million in formwork costs and completed the walls safely and on schedule. ciria report 108 concrete pressure on formwork
The report clearly states that for walls > 4m, the maximum pressure reaches a plateau. Pouring faster above 4m doesn't increase pressure—it just risks a blowout at the bottom. ciria report 108 concrete pressure on formwork
For typical structural concrete (slump 50–100 mm, without retarders), C1 ≈ 7.2 and C2 ≈ 18, giving: ciria report 108 concrete pressure on formwork