UNDERWATER CONCRETING. EXPERIENCES IN THE FIELD

ERFARENHETER VID UNDERVATTENSGJUTNING AV BROSTOED

The Swedish National Road Administration has followed up the underwater concreting of 46 foundation slabs for bridge piers. In 35 cases the concrete was pumped directly into concreting pipes, in 11 cases into open funnels on the top of conventional tremie pipes. In 8 cases the concreteing failed and extensive reinforcement of the foundation slabs became necessary. Failures were most frequent in the first concreted slabs, but even later on about 10% of the slabs failed. The main cause of failures was poor consistency and flowing-ability of the concrete. Often the concreting pipes were badly controlled and became drawn up too much, when poor consistency resulted in high values of the pumping pressure. Reinforcement bars also sometimes led to failures when the concrete was pumped at a high velocity around them. Good results were obtained with special pumping-equipment (rigid arm link with damping spring, air-driven valve in the bottom of the concreting tube, end-pipe of at least - 5" and end-cone of - 8", pumping capcity strangled to about 1/3 at starting and at critical points) and with good concrete consistency (slump 15-17 cm at the mixing station). Vibrating of underwater concrete seems to be possible and increases the concrete strength. The mean strength of 178 drilled cores was 33,7 mpa, standard deviation 7,7 mpa, and of 96 standard cubes 46,8 mpa, standard deviation 5,3 mpa. This indicates a loss in strength of about 15 mpa caused by the concreting method. (TRRL)

  • Availability:
  • Corporate Authors:

    Nordiska Betongfoerbundet

    Fack
    10044 Stockholm 70,   Sweden 
  • Authors:
    • Vontergaard, J L
  • Publication Date: 1979

Language

  • Swedish

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 16-22
  • Serial:
    • Nordisk Betong
    • Volume: 23
    • Issue Number: 5
    • Publisher: Nordiska Betongfoerbundet
    • ISSN: 002913070029-1307

Subject/Index Terms

Filing Info

  • Accession Number: 00310568
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • Files: ITRD, TRIS
  • Created Date: Jul 22 1980 12:00AM