The rheology of fresh cement paste containing polysaccharide gums

The addition of polysaccharide gums to cement pastes has a considerable effect on their rheological properties. These admixtures are currently used in several practical applications such as anti-bleeding agents, anti wash out admixtures, and pump and sag resistance additives. The success of these applications depends on the rheological properties of the grout. Experimental results reported here show that the addition of polysaccharide gums in cement paste systems has a significantly higher effect on the viscosity at low shear rates than at higher shear rates. Additionally, a considerably high thixotropic behavior has been found in the form of an apparent viscosity recovery, this effect being higher for combinations of the polysaccharide gum and high range water reducers.