Applying CIRIA 108, they measured the setting time (E) of the site mix (a high-density concrete with PFA) at 3.5 hours and controlled the rate of rise (R) to 1.2 m/hour. The resulting P_max was just 120 kN/m².
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 ciria report 108 concrete pressure on formwork
Do you still use the CIRIA 108 nomographs, or have you moved to pressure sensors and digital monitoring? Applying CIRIA 108, they measured the setting time
Recognizing this gap, CIRIA initiated a research program in the late 1970s, led by A.C. Hargreaves and others, to measure actual lateral pressures during real-world pours. The result was , which provided: It provides specific formulas to determine maximum pressure
Fresh out of university, we all learned the classic formula: Pressure = Density x Height ( ( p = \rho gh ) ). But anyone who has watched a formwork blowout knows that fresh concrete isn’t a fluid.