Question

True/False: When pouring tall walls or columns the concrete must have the appropriate slump not to be too wet or fluid. Also, it must be poured in lifts to prevent too much pressure toward the bottom of the formwork.

Answer 1

It is true that when pouring tall walls or columns, concrete must be at the correct slump and poured in lifts to manage the fluidity and pressure. This ensures structural integrity and prevents formwork failure.

Step-by-step explanation:

The statement is true: When pouring tall walls or columns, the concrete must have the appropriate slump to avoid being too wet or fluid. This is crucial to prevent the possibility of collapse or failure of the concrete structure due to excessive fluidity that can lead to pressure build-up at the bottom of the formwork. It is also essential to pour concrete in lifts, as doing so in a single pour can generate a significant amount of pressure at the bottom, potentially causing the formwork to fail.

Regarding the specifics of concrete flow, as described by the scenario, one could calculate whether the flow is laminar or turbulent using the Reynolds number. The Reynolds number requires the density of the concrete, the viscosity, the flow rate, and the diameter of the hose to be known. With these factors, it is possible to determine the smoothness of the flow within the hose, which is important for ensuring steady pumping and reducing the risk of clogs or uneven application.