Formwork: Ciria Report 108 Concrete Pressure On

To address these, CIRIA issued subsequent guidance (e.g., C660 "Formwork Pressure"), but Report 108 remains the foundational reference.

Rough form liners (e.g., plywood) and stiff formwork can reduce measured pressure compared to smooth steel forms. CIRIA 108 provides reduction factors but recommends caution—friction effects are unreliable. ciria report 108 concrete pressure on formwork

Most contractors take E from a concrete test certificate done at 20°C. If your pour is at 10°C, E might be 3x longer. Always adjust E for ambient and concrete temperature. A 5°C drop can double E. To address these, CIRIA issued subsequent guidance (e

), after which it remains constant to the bottom of the formwork. Key Factors Influencing Pressure Most contractors take E from a concrete test

The formula is elegant, powerful, and—when used correctly—profoundly safe. It recognizes that concrete is not an enemy to be contained, but a material to be understood.