OPTIMIZATION OF A CEMENT GROUT FORMULATION FOR DUCTS CONTAINING POST-TENSIONED CABLES

Early stiffening reported in the field placement of a developmental, prepackaged cement (PPC) grout (comprising Type 10 Portland cement, silica fume, superplasticizer and aluminum powder) has been investigated. The thickening behaviour of the grout was duplicated in the laboratory, and its chemical, physical and rheological properties examined under conditions of mixing, pressure and temperature similar to those on site. The PPC grout exhibited complex rheological behaviour involving both a shear-dependent increase in viscosity (thixotropy) and time-dependent chemical thickening. Chemical incompatibility of the Portland cement and superplasticizer was subsequently identified as the cause of the stiffening, although the underlying mechanism remains to be determined. Based on these findings, an optimized grout formulation was developed using alternative sources of Type 10 Portland cement and superplasticizer. The optimized grout was strongly cohesive, while having superior flow characteristics to the PPC material. Also, corrosion parameters related to durability were comparable or improved. It has been recommended that the optimized grout be tested at larger scale and under simulated field conditions to verify its acceptability. It will also be important to identify the nature of the superplastizer-cement incompatibility, with the purpose of developing a practical cement specification for use in grouting operations.

  • Corporate Authors:

    Ontario Ministry of Transportation

    Research and Development Branch, 1201 Wilson Avenue
    Downsview, Ontario  Canada  M3M 1J8
  • Authors:
    • HEMMINGS, R T
    • Cornelius, B J
  • Publication Date: 1991-7

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 56 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00620664
  • Record Type: Publication
  • Report/Paper Numbers: MAT-91-08
  • Files: TRIS
  • Created Date: Mar 31 1992 12:00AM