Self consolidating concrete form pressure
Testing has also been conducted in field installations.
A 28-foot high wall was constructed in the structures lab at the University of Illinois at Urbana-Champaign.
The maximum pressure reached was 5.5 psi, which was only approximately 20% of the maximum hydrostatic pressure at the point of measurement.
This wall was filled at a relatively slow rate, maximum of 5.5 ft/hr, due to the large dimensions of the structure (5 ft thick, 80 ft long and 28 ft high). A companion test column was fabricated which involved filling a 10.5-ft tall column.
The cylinder has two pressure cells mounted on the sides.
One is used to measure total horizontal pressure and the second sensor is used to measure pore water pressure.
Their testing apparatus utilizes a short column of concrete, 300 mm, in a steel mold. A loading frame is used to apply a load on the top of the column of concrete to simulate the effect of a much larger column of concrete.
This can also apply increasing loads over time to simulate varying casting rates.
That load is maintained for several hours to simulate the end of filling and the material at rest. Northwestern University Laboratory Set-Up It has been found through many laboratory trials that the particular material chosen for the formwork is of great importance in studying formwork pressure.This guidance generally limits contractors to short walls or extremely strong formwork.