MIDNIGHT PATCHES CURE BEFORE 6 A.M. DEADLINE

This note describes how, faced with liquidation damages of $10,000 per hour each morning, a contractor repairing a runway at Chicago's Midway Airport made sure that the concrete would harden before deadline. The specifications required a compressive strength of 3,000 psi in four hours. Since the cement used actually started setting in about 10 minutes, a citric acid retarder had to be added to delay the set by about 30 minutes. The contract required the replacing of the critical area where two runways intersect. Since the fast-setting concrete has a tendency to set in a transit mixer, mixing trucks that carry the components in separate bins were used, and mixing was done just prior to use.

  • Availability:
  • Corporate Authors:

    McGraw-Hill, Incorporated

    330 West 42nd Street
    New York, NY  United States  10036
  • Publication Date: 1991-9-2

Media Info

  • Pagination: p. 14
  • Serial:
    • ENR
    • Volume: 227
    • Issue Number: 9
    • Publisher: McGraw-Hill, Incorporated
    • ISSN: 0891-9526

Subject/Index Terms

Filing Info

  • Accession Number: 00615228
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 30 1991 12:00AM