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

You are pouring a 4m high wall with:

In cold weather with fast pouring, CIRIA 108 predicts higher pressure than hydrostatic? No—the formula caps at hydrostatic. In the above, 83.1 kN/m² is actually less than 70.5? Let's correct: 23.5 * 3 = 70.5. CIRIA gave 83.1? That's impossible because CIRIA caps at hydrostatic. Let's re-run: ciria report 108 concrete pressure on formwork

[ P_max = 11.4 + \frac785RT + 17.8 ]

In the late 1970s, a new hospital wing was being cast in the UK. During a tall wall pour, the formwork suddenly blew out—halfway up, the plywood faces bulged, then burst. Wet concrete flooded the rebar cage, injuring several workers. The investigation revealed a shocking truth: the forms had been designed using outdated American Concrete Institute (ACI) pressure formulas that assumed a slow, layer-by-layer pour. But the contractor was using a modern concrete mix with superplasticizers and pumping from the bottom—two factors that dramatically increased lateral pressure. You are pouring a 4m high wall with: