Ciria Report 108 Concrete Pressure On Formwork !!top!! Here

CIRIA Report 108, "Concrete pressure on formwork," serves as a foundational guide for calculating the lateral pressure exerted by fresh concrete on temporary formwork structures, accounting for variables like rate of rise, temperature, and mix composition. It provides specific formulas to determine maximum pressure ( Pmaxcap P sub m a x end-sub

Hydrostatic check: D × H = 24 × 8 = 192 kN/m². Since 115.2 < 192, the CIRIA value controls. You can design formwork for 115 kN/m², not 192. That is a 40% reduction in required tie strength.

Best Practices for Modern Formwork Design Using CIRIA 108

To safely and economically design formwork today: ciria report 108 concrete pressure on formwork

Limitations & Cautions:

CIRIA 108 is often considered more flexible for low- to moderate-rate pours, while EN 12812 is more prescriptive for safety-critical applications. Many formwork manufacturers now produce load tables that directly reference CIRIA 108, Class 1 or 2 loading. CIRIA Report 108, "Concrete pressure on formwork," serves

1. The Problem: Hydrostatics vs. Reality

To understand the importance of Report 108, one must first understand the problem it solved. Before 1985, formwork designers often relied on simplistic assumptions.

Critical Factors That Influence R and E

The magic of CIRIA 108 lies in accurately capturing Rate (R) and Setting Time (E). Misjudging these is the primary cause of formwork failure. You can design formwork for 115 kN/m², not 192

Step 5: Monitor during the pour. Have a ready-mix engineer track the concrete temperature. If the truck arrives cooler than expected, recalculate P_max immediately.