Experimental and analytical models of flexural behavior of U-shaped reactive powder concrete permanent beam formworks

Abstract

The primary purpose of this study was to analyze the application of reactive powder concrete (RPC) in U-shaped permanent beam formworks. Experiments were conducted to investigate the mechanical (compression and tensile) properties of RPC and the flexural capacity of permanent formworks. Six U-shaped permanent beam formworks were tested under four-point flexural loading until failure. Additional parameters such as side wall thickness, bottom board thickness, and the reinforcement ratio were analyzed to investigate the flexural behavior of the formworks before pouring. The moment capacity, load-deformation curve, and failure process and mode of the specimens were examined. All the specimens failed the flexural test and exhibited a bending failure mode similar to that of concrete beams. The test results revealed that increasing the thickness of the bottom board of the U-shaped RPC permanent formwork was effective in delaying the cracking moment of the U-shaped formwork. We created analytical models to calculate the cracking moment of U-shaped RPC permanent beam formworks. A comparison of the analytical and experimental results revealed that our simplified analytical model predicts the experimental results better than existing models do.