Ciria Report 108 Concrete Pressure On Formwork !new! -

CIRIA Report 108 (1985) provides a standard, non-hydrostatic method for calculating lateral concrete pressure on vertical formwork by accounting for placement rate, temperature, and concrete mix design. The model determines the maximum pressure based on either full hydrostatic pressure or a formula covering the "arch effect," which is widely recognized in standards like BS 5975. For more information, visit the official CIRIA R108 overview Concrete pressure on formwork (R108) - CIRIA

Design formwork with adequate strength and stiffness: Ensure that the formwork is designed to resist the expected concrete pressure.
Use a well-designed concrete mix: Select a concrete mix that balances workability, strength, and density.
Place concrete at a controlled rate: Regulate the rate of concrete placement to avoid excessive pressure on the formwork.
Monitor and control pressure: Use pressure-measuring devices to monitor and control concrete pressure during placement.

CIRIA Report 108 (1985) establishes the standard UK methodology for calculating lateral concrete pressure on vertical formwork, utilizing factors like placement rate, temperature, and mix composition to determine maximum pressure. Referenced in BS 5975:2019, the report addresses both hydrostatic and reduced pressure scenarios to optimize formwork design. Purchase the report at the CIRIA Official Bookshop. Concrete pressure on formwork - BS5975:2019 - Prontubeam ciria report 108 concrete pressure on formwork

C. Comparison with EN 12812 With the introduction of the Eurocode (BS EN 12812) for falsework, there is a conflict in methodology. EN 12812 uses a different coefficient approach ($H_max$). However, many practitioners still prefer CIRIA R108 because EN 12812 can be complex to navigate for simple wall pours, and CIRIA is viewed as having a "calibrated" safety record in the UK industry. CIRIA Report 108 (1985) provides a standard, non-hydrostatic

The maximum lateral pressure (P_max) is calculated using empirical formulas derived from the report. A simplified version for ordinary concrete (slump 50–100 mm) is: Design formwork with adequate strength and stiffness :