Ciria Report 108 Concrete Pressure On Formwork ⚡ [VALIDATED]

The methodology outlines a step-by-step mathematical approach to determine the design lateral pressure, ensuring formwork is neither under-designed for safety nor over-designed to the point of financial waste. Step 1: Determine the Concrete Mix Group

Published by the Construction Industry Research and Information Association (CIRIA), Report 108 provides detailed empirical guidance on the lateral pressure exerted by fresh concrete on vertical formwork (walls and columns). It was developed to move away from relying solely on hydrostatic pressure—which assumes concrete behaves as a perfect liquid—towards a more realistic model that accounts for the stiffening of concrete over time.

Based on the findings of CIRIA Report 108, the following recommendations and best practices are proposed:

For decades, the methods in this report have helped engineers optimize the design of formwork, ensuring it is strong enough to hold the concrete while avoiding over-design, which wastes materials and money. 2. Fundamental Principles: Hydrostatic vs. Real Pressure ciria report 108 concrete pressure on formwork

(Deducted 0.5 only due to the need for supplementary guidance on modern admixtures).

) that fresh concrete exerts on vertical or near-vertical formwork faces.

P.J. Clear Publisher: Construction Industry Research and Information Association (CIRIA) Year: 1990 (Reprinted with minor amendments 1995) Based on the findings of CIRIA Report 108,

Don't rely on lab data. Take a trowel to the concrete in the jump form. If it isn't green (setting), you are still at maximum pressure.

Back to Basics: Why CIRIA Report 108 Still Rules Concrete Pressure Design

Categorized by specific modern consistency classes (F1 to F6). Detailed assessment of modern chemical additives. Not fully covered (developed post-report). Explicitly covers SCC up to full hydrostatic pressure. Integrates SCC characteristics. Limitations of CIRIA 108 Real Pressure (Deducted 0

This article provides a comprehensive breakdown of CIRIA Report 108—its history, key formulas, practical applications, and why it remains indispensable for safety and efficiency in concrete placement.

CIRIA Report 108 provides engineers with a reliable, temperature- and rate-based method to calculate lateral concrete pressure on formwork, balancing safety with material efficiency. For any concrete pour requiring designed formwork, understanding this report is a fundamental skill.