The objective of this project was the development of a technique for repairing cracked structural bridge concrete. The method developed consists of sealing the crack, drilling holes at 45 deg to the deck surface crossing the crack plane with epoxy pumped under low pressure, and placing a rebar in the drilled hole in a position to span the crack. The epoxy bonds the bar to the walls of the hole, filling the crack plane and bonding the cracked concrete surfaces together in monolithic form, which thus reinforces the section. The epoxy injection equipment used was developed for hollow plane injection. A modified injection nozzle was built, and an enlarged vacuum swivel was designed, developed, and built. The hollow-stem carbide-tipped vacuum drill bits were 19.1 mm (0.75 in) in diameter and up to 2.44 m (8ft) long. A mechanical-advantage motion detector was designed and built and used to detect fractional vertical and horizontal motions of 1.19 mm (3/64 in) and record them as 19.1-mm (0.75-in) motion. Drilling to a depth of 2.1 m (7 ft) required 22 min. Fifteen 0.914-m (36-in) long rebars were placed in repair zones. All crack injection attempted was successfully completed in 3 working d. Seventeen months after completion of the repair, no motion had been detected and the repair appeared to be permanent. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 34-36
  • Monograph Title: Bridge design, evaluation, and repair
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00195911
  • Record Type: Publication
  • ISBN: 0309028191
  • Files: TRIS, TRB
  • Created Date: Aug 15 1979 12:00AM