The American Concrete Institute (ACI) has released a paper called Formwork Pressure Model for Self-Consolidating Concrete Using Pressure Decay Signature.
The paper, written by Jacob D. Henschen, Daniel I. Castaneda, and David A. Lange, addresses industry guidelines which recommends formwork is designed to withstand full hydrostatic pressures when using self-consolidating concrete (SCC) and highly flowable concrete.
ACI says: “full hydrostatic pressures are seldom observed during SCC pours, meaning that it is possible to safely relax formwork design specifications.”
According to the document, “researchers have developed models that incorporate lab-tested material values to predict formwork pressure, but are affected by changing concrete mixture design, air temperature, humidity, and other factors that cannot be accounted for quickly.”
This study presented a simple field test method and model that predicts the formwork pressure using a calibrated behaviour, which is called pressure decay signature.
“The simple formwork pressure model is shown to agree well with experimentally measured values during the construction of two tall-walls, suggesting that this method and model can contribute to increased cost efficiency of SCC construction while maintaining safe practices,” ACI adds.
