Ciria Report 108 Concrete Pressure On Formwork Info

Published by the Construction Industry Research and Information Association (CIRIA), Report 108 fundamentally changed how the industry calculates the lateral pressure exerted by fresh concrete. Even with the advent of Self-Compacting Concrete (SCC) and modern admixtures, the principles laid out in this 1985 report remain the industry benchmark.

In the late 1970s and early 1980s, CIRIA undertook a massive research project, observing real-world pours in walls, columns, and slipforms. The result, published in , provided empirical evidence that concrete stiffens (develops "shear strength") as it hydrates, thereby reducing peak pressure significantly below the hydrostatic maximum. ciria report 108 concrete pressure on formwork

Research (including later CIRIA updates) shows that for SCC, the coefficient (1.2) is insufficient. SCC can maintain fluid-like behavior for longer, leading to near-hydrostatic pressures. The result, published in , provided empirical evidence

By trusting the CIRIA 108 calculation, they saved over £2 million in formwork costs and completed the walls safely and on schedule. Nearly 40 years after its publication, CIRIA Report 108 "Concrete Pressure on Formwork" remains the gold standard for rational formwork design. It shifted the industry from fearful over-design to intelligent, risk-aware engineering.

Introduction In the world of concrete construction, few elements are as critical—and as often misunderstood—as lateral pressure on vertical formwork. Over-pour a wall or misjudge the setting rate of a column, and the result is a blowout: thousands of dollars in wasted material, potential worker injury, and crippled project timelines.

Order a penetration resistance test (ASTM C403 / BS EN 480-2) on your specific mix at the expected site temperature.