Viscosity evaluation of SCC based on flow simulation in the L-box test

摘要

Recent interest in self-compacting concrete (SCC) has increased as more structures around the world are now incorporating SCC where there is need to fill the framework and encapsulate the reinforcement without any mechanical consolidation. Fresh SCC flows under its own weight to fill the formwork completely and self-compacts without any segregation and blocking. To gain a better understanding of SCC properties and their effects on the passing ability of SCC, the present work aimed to simulate numerically the SCC flow in the L-box test. As concrete flow in the L-box test is a free surface flow with large deformations, a smooth particle hydrodynamics (SPH) method was used for the simulation. SCC was assumed as a non-Newtonian Bingham fluid where the shear-strain rate ratio was linear and characterised by viscosity and yield stress. The flow simulation for two kinds of concrete (SCC and high performance concrete) were numerically conducted using the SPH method and the results were compared with the experimental data. To propose the appropriate viscosity-yield stress range for SCC, a comprehensive parametric study was carried out considering different viscosities and yield stresses. The results showed that concrete with viscosity between 50 Pa s and 270 Pa s can be considered as SCC.