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

Abstract

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.

Combined impacts of polypropylene fibres on workability, strength and permeability of SCC

“…Second, the 80% mixture of water-reducer and water is added and mixed for 1 min, and then the remaining mixture is added for 1 min more of mixing. Finally, the workability of fresh PFRSCC is tested by the slump-flow test and U-box test (Lashkarbolouk et al, 2013). When the slump flow (SF) is not less than 550 mm while the filling height difference (äh) by U-box is not more than 30 mm, the workability of fresh PFRSCC meets the requirements; if either SF or äh fails to meet the requirements, the amount of binder material or water-reducer is increased to improve the workability of the fresh PFRSCC (He and Yang, 2009;He and Shen, 2013).…”

A critical review of rheological models in self-compacting concrete for sustainable structures

“…Results of the model show that the yield stress at the measured times and the aggregate distribution at the end of the flow were consistent with measured values from the laboratory and this confirms also the capability of the SPH to model the slump flow and aggregate distribution throughout the flow situation in self-compacting concrete. Lashkarbolouk et al 27 investigated the self-compacting concrete flow simulation through the L-box configuration to study the passing ability of the mix for a non-Newtonian Bingham behavior considering a linear shear to strain rate ratio embodied with the material’s yield stress and plastic viscosity. The results showed values consistent with available literature and laboratory results.…”

3D Simulation of Self‐Compacting Concrete Flow Based on MRT‐LBM

“…In this regard, the meshless methods have an advantage over the mesh-based methods. As a meshless Lagrangian method, the SPH method is good at modeling Newtonian and non-Newtonian flows with a free surface [7] and has been chosen for simulating the SCC flow by Kulasegaram et al [8], Lashkarbolouk et al [9], Qiu [10], Abo Dhaheer et al [11], and Wu et al [12]. However, the SPH method has difficulties in solving problems with complex solid boundary conditions.…”