fluid pressure

mail

how do I find ( what formula should I use ) to find the pressure on the formwork for a concrete column at a given piont in the formwork. I found a formula but not sure if it is right.

density of concrete x distance from top of formwork / 100

I have another formula for sideways thrust but dont know which to use
Pc = pgh
Thanks for any replies

rockorocko

I think it's just Pressure = mass x gravity/Area where mass = Density x Volume Sorry my understanding is not very well, but if you're talking about something like a column holding a floor then, Pressure (floor down) = Pressure (column up) This is only true of the area of the floor does not bend and you're putting it right in the middle. Otherwise it can be a bit complicated.

bnt

I know this is an old thread - still thought I should clarify. The formula you need is P = ρ g h

ρ (rho) is the density of the substance, in this case concrete, typically 2400 kg/m³. The assumption is that the poured concrete acts as fluid i.e. the pressure at a point is the same in all directions (up, down, sideways).

Since ρ is constant, and g is constant (gravity), the only variable is h, the depth. So you can boil the formula down to P = 24 kPa per metre of depth. e.g. 120kPa at 5m depth.