Yield Model of High Fluidity Concrete in Fresh State

This paper presents a microscopic approach to model the yield condition of high fluidity concrete in the fresh state for the rheological evaluation and the numerical flow simulation to optimize its workability and composition. Based on considering fresh concrete as a type of particle assembly containing water, cohesive particles (cement grains), and cohesionless particles (aggregate grains), the directions and magnitudes of inter-particle forces are examined, the shear deformation resistance of fresh concrete is investigated. Then, an equation of yield condition is derived, and a yield model is proposed for high fluidity concrete in fresh concrete. Furthermore, the dependence of the yield stress on interparticle friction, temperature, normal stress on the shear plane, etc., is clarified on the basis of the obtained yield condition equation.