Bouyancy force on fresh concrete?

Question

How to solve the bouyancy force on a 500mm dia FRC pipe that has to be concreted at midsection (longitudinal) of the pipe?

Answer 1

The buoyancy force on the pipe is the weight of the concrete which would be there if the pipe were not there; The common way of saying this is that the buoyant force is equal to the weight of the displaced concrete. To see what force will be require to restrain the pipe from floating out, subtract the weight of the pipe from the buoyant force. Because the pipe is FRC, the density of the walls is about equal to the density of the concrete, so you could just find the buoyant force for the inside diameter of the pipe.