Self consolidating concrete formwork pressure dating ftort nelson
In addition, the correlation between the formwork pressure response and the loss of slump flow is derived, providing an approximate method to estimate the reduction in formwork pressure. ACI 347R) do not specifically address SCC, but recommend that unless a method based on appropriate experimental data is available, formwork should be designed to withstand the full hydrostatic head of fluid concrete.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 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.The column was filled at a rate of 60 ft/hr and the highest pressure measured one foot from the bottom.The highest pressure recorded was 80% of hydrostatic pressure.
Additionally, the highest pressure was reached long before the pour was finished.
Owing to enhanced filling ability, self-consolidating concrete offers accelerated casting and superior quality control during construction.
However, its high fluidity and high placement rate increase the lateral pressure on the formwork, necessitating an extensive supporting system to retain fresh mixtures in a desired shape.
The general procedure is to fill the cylinder and then apply an ever increasing load until a pre-determined maximum load representing a particular column height.
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.