Report 108 Concrete Pressure On Formwork | Ciria

Before Report 108, formwork designers relied on empirical rules-of-thumb or overly conservative hydrostatic pressure models. The hydrostatic assumption—that fresh concrete behaves exactly like a liquid (pressure = density × height)—led to massively over-engineered (and expensive) formwork. Conversely, simplified rules like "pressure = 1.5 × height" often proved unsafe for high-slump, fast-pouring conditions.

CIRIA Report 108, titled “Concrete Pressure on Formwork,” is a widely cited guidance document that synthesizes research and practice on the lateral pressures exerted by fresh (plastic) concrete against formwork during casting. Its primary aim is to help engineers, formwork designers and site teams predict and safely design formwork systems for vertical and inclined concrete elements. ciria report 108 concrete pressure on formwork