Stability of Cement Grout: Study of Sedimentation Phenomena

Abstract

The grouts are suspensions containing cement used in the technique of prestressing by post-tension. Cement, from its chemical nature, protects the wire ropes (strands) from corrosion. To be able to play correctly this protective role, the grout must remain homogeneous and must entirely cover the strands. The lack of stability of the grouts, which results in packing or sedimentation, is a major problem. In this article, we try to correlate the rheological properties of the grout with its capacity to remain homogeneous. We show that an increase in the concentration of superplasticizer, a polymer solution, decreases the thixotropic behavior of the grout, but on the other hand, increases the effects of sedimentation. We explain this phenomenon by the modification of the structure of a three-dimensional network in relation to the interparticle interactions.

Keywords

• prestressing
• cement grout
• rheology
• sedimentation
• interactions
• thixotropy