Deformability prediction model for self-compacting concrete

The aim of the current study is to propose a model for predicting deformability of powder-type self-compacting concrete (SCC) based on theoretical and empirical approaches. Deformability, one of the essential functions for SCC's filling ability, was defined and determined in this study to include deformation capacity, indicated by slump flow value, and velocity of deformation, measured by 500 mm slump flow time (T₅₀₀). In the process of mix proportioning, both deformation properties should be considered to achieve good deformability. Prediction models for deformation capacity and velocity of deformation were developed based on the concepts of free water content, water retainability of solid particles and inter-particle forces in the concrete. It was found that slump flow and T₅₀₀ varied mainly with free water content in mixtures and were also affected by various factors, such as ratio of paste volume to void content of compacted aggregate phase, surface area, shape and water retainability of powder materials and aggregates and efficiency and dosage of superplasticiser. Experimental results from the current authors and other researchers were used in the verification of the proposed models. It was evident that the proposed models could be used to predict the slump flow and T₅₀₀ with satisfactory accuracy.