Construction-stage structural performance of beams with steel permanent formwork: Experimental and numerical approach

This study presents experimental and numerical investigations on the construction-stage structural performance of steel permanent formwork beams. Four specimens were fabricated with rib spacing and fixing plate spacing as variables. Vertical deflection of the bottom plate and horizontal deformation of the side plates were measured under fresh concrete loading to quantitatively analyze deformation characteristics. Finite element (FE) analyses were performed based on the experimental results, verifying the accuracy of the analytical model through comparison with test results. Using the validated model, 31 parametric analyses were conducted to evaluate the effects of rib spacing, fixing plate spacing and thickness, and welding length. Furthermore, 486 extended analyses were performed to develop a multiple regression model for predicting the horizontal deformation of the side plates. The proposed equation demonstrated high predictive accuracy and is expected to contribute to the rational evaluation of formwork behavior at the design stage.