Fresh Concrete Lateral Pressure On Formwork

Knowledge of concrete pressure is critical for the economical and safe design of formwork for concrete construction. This paper summarizes results a study conducted to improve the prediction of fresh concrete lateral pressures on formwork. Research tasks were to collect data published in the last 25 years on concrete lateral pressure against formwork, and analyze this data with regards to the effects of various cement types, admixtures, and placement rates. Recommendations are presented which include applying unit weight and chemistry modification factors to the previous ACI 347R-94 lateral pressure prediction equations and extending the placement rates over which the equations are applicable. These recommendations have been adopted in ACI 347-01.