Patent · US Expired

Compound cement, more particularly usable in bore holes

US4877452A · kind A · utility

6Cited by
0References
4Claims
0Family size

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Key dates

Filing dateApr 28, 1988
Grant dateOct 31, 1989
Priority date
Expiry dateApr 28, 2008

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P40/10
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

Abstract

The invention concerns a compound cement containing cement and a blast-furnace slag, more particularly for bore holes. This compound cement is characterized in that it comprises the following components: PA0 a Portland cement presenting, by weight, a magnesium oxide content of max. 6%, a sulphur trioxide content of max. 3%, an insoluble residue of max. 0.75%, a tricalcium silicate content between 48 and 65%, a tricalcium aluminate content of max. 3%, a total amount formed by the amount of tetracalcium aluminoferrite, plus the amount of dicalcium ferrite, plus two times the amount of tricalcium aluminate which is at most equal to 24%, and a total amount of alkalies, calculated as sodium oxide equivalents, of max. 0.75%. PA0 and a ground blast-furnace slag with a vitrification rate of 90 to 100%; these two components presenting a similar mesh size, comprised between 2,800 and 3,000 cm.sup.2 /g, and being mixed together in the following wt-% proportion: 50 to 10% of Portland cement and 50 to 90% of ground slag.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.