EFFECT OF WATER VELOCITY ON PERFORMANCE OF UNDERWATER SELF-CONSOLIDATING CONCRETE

Although considerable advances have been made in enhancing in-place properties of concrete cast in standing water, little is known about the performance of concrete cast in flowing water. A hydraulic channel measuring 6 m in length was constructed in the laboratory to cast concrete in water flowing at velocities up to 1.0 m/s. A detailed investigation was carried out to determine the effect of the dosage of welan gum and cellulose-based antiwashout admixtures on the washout resistance of concrete placed in flowing water. The investigated mixtures were prepared with a water-cementitious materials ratio (w/cm) of 0.41 and 0.47 and contained up to 10% silica fume replacement. The high-range water reducer dosage was adjusted to maintain an approximate slump flow consistency of 500 mm to ensure self-consolidation and obtain relatively flat underwater surfaces. A concrete having a slump flow and a standard washout mass loss of 500 mm and 5%, respectively, was cast in water circulating at 0.0 m/s, 0.10 m/s, 0.40 m/s, and 0.65 m/s to evaluate in-place strength and unit weight. The selected mixture incorporated a medium dosage of welan gum and 8% silica fume and had a w/cm of 0.41. Test results show that despite the highly fluid nature of the concrete, considerably greater washout resistance can be secured when the dosage of antiwashout admixture is increased, the w/cm is reduced, and 10% silica fume is incorporated. The increase in water velocity can lead to a net reduction in in-place strength. The optimized high-performance concrete developed an in-place compressive and splitting tensile strength greater than 70% of control samples along the 5-m blocks cast in water current inferior to 0.4 m/s. Such strengths ranged between 50-65% and 70-80%, respectively, when the velocity increased to 0.65 m/s.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/13846872
• Corporate Authors:

  American Concrete Institute (ACI)

  38800 Country Club Drive
  Farmington Hills, MI  United States  48331
• Authors:
  • Sonebi, M
  • Khayat, K H
• Publication Date: 1999-9

Language

• English

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 519-528
• Serial:
  • ACI Materials Journal
  • Volume: 96
  • Issue Number: 5
  • Publisher: American Concrete Institute (ACI)
  • ISSN: 0889-325X
  • Serial URL: https://www.concrete.org/publications/acimaterialsjournal.aspx

Subject/Index Terms

• TRT Terms: Admixtures; Cement content; Channels (Waterways); Compressive strength; Concrete; Flow; High performance concrete; Laboratory tests; Moisture content; Repairing; Silica fume; Slump test; Stability (Mechanics); Tensile strength; Tremie concrete; Underwater construction; Velocity; Water; Water cement ratio; Weight; Workability
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00781625
• Record Type: Publication
• Contract Numbers: D CA-96K-0049, CMS-9796326
• Files: TRIS
• Created Date: Jan 5 2001 12:00AM