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Hansson (1993) stated that the rheological behavior of a cement-based grout is difficult to define because of the concentration and characteristics of the particles as well as the suspension medium. The rheological behavior is influenced by the chemical reactions in progress during the hydration of the cement and the thixotropy is dominant at short cycle times. The rheological models are used to describe the relationship between shear stress and shear rate. Syrjala (1996) stated that there was no general rheological constitutive model1 INTRODUCTION1.1 Rheology and viscosity of fluidsRheology can be defined as the study of the change in the form and flow of the matter. The scope of rheology includes elasticity, viscosity, and plasticity. Rheology of grouts is a way of describing its properties without paying any attention to whether it is a homogenous grout or a mixture of grains in a grout (Eklund, 2005). It is normally applied to fluid materials (or materials that exhibit a time dependent response to stress). It can also be defined as the study of the flow of the grout flows, before the setting point is reached. This is crucial due to the fact that the grout must be placed by some kind of mechanical process like, pumping into the prepared forms. Cement grout based rheology is characterized by at least two parameters: yield stress and plastic viscosity. In a similar way, an elastic solid is characterized by two parameters: Young’s modulus and Poisson’s ratio (Bentz et al., 2006). |
