Ciria Report 108 Concrete Pressure On Formwork
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
- CIRIA Report 108: Concrete Pressure on Formwork (2017)
- Construction Industry Research and Information Association (CIRIA)
- British Standards Institution (BSI) - BS 8533-1:2017
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
Common Mistakes When Applying CIRIA Report 108
Despite its clarity, engineers frequently misapply the report: CIRIA Report 108 (1985) provides a standard, non-hydrostatic
The Problem CIRIA 108 Solved
In the 1970s and 80s, engineers realized the "fluid head" method was wasting millions on over-engineered formwork. Concrete stiffens as it hydrates. CIRIA 108 introduced the concept of "pressure relief" based on setting time. CIRIA Report 108: Concrete Pressure on Formwork (2017)
The Gold Standard: An In-Depth Look at CIRIA Report 108 and Concrete Formwork Pressure
In the world of civil engineering and construction, few documents have achieved the status of a "silent standard" quite like CIRIA Report 108: Concrete Pressure on Formwork. Published in 1985 by the Construction Industry Research and Information Association (CIRIA), this report revolutionized how engineers calculate the lateral pressure exerted by fresh concrete on vertical formwork.
Verdict: ACI 347 uses empirical curves based on column size. CIRIA 108 is more scientific for walls and unusual geometries because it explicitly accounts for the concrete's hydration chemistry. For complex projects, many engineers run both and use the higher (safer) value.
The appendices provide additional information and examples to support the report's findings and recommendations.
