An enhanced mix-design method for self-compacting concrete based on paste rheological threshold theory and equivalent mortar film thickness theories

Abstract

• Coarse aggregate properties consist of shape, gradation, and content. • Coarse aggregate properties are quantified by equivalent specific surface area. • Equivalent mortar film thickness was used to modify the original model. • The modified model was verified with different coarse aggregate properties. This paper puts forward an enhanced mix design method for self-compacting concrete (SCC) based on paste rheological threshold theory and equivalent mortar film thickness theories. 18 sets of paste and SCC tests were carried out to test the initial mix design method with coarse aggregate contents of 285, 315, and 322 L/m 3 , the results show that the initial mix design method cannot accurately predict the SCC test results. The equivalent specific surface area of coarse aggregate (SSA eq ) was chosen to quantify and represent the particles’ shape, gradation, and contents on mortar film thickness, and the equivalent mortar film thickness was proposed to modify the original rheological model. In addition, 36 sets of paste and SCC tests with different coarse aggregate characteristics were prepared to verify the enhanced method. Using prediction accuracy formula to evaluate the enhanced mix design method. Both methods are used to predict the fresh SCC. Results show that the average value of relative accuracies and Intersection-over-Union (IoU) in the enhanced method are, 0.84, 0.79, respectively, whereas in the original method are, 0.60, 0.59, respectively.