Flame cleaning of concrete has been investigated in field tests made on large concrete surfaces, as well as in laboratory tests carried out on small concrete slabs which had been specially prepared for this investigation. The tests showed that the thickness of the concrete layer which is removed by cleaning is in part dependent on the speed at which the burner is moved. Certain definite properties of the concrete surface influence the efficiency of flame cleaning. For instance, a higher moisture content of the concrete increase the rate of concrete removal. In normal cases, when the burner is moved at a speed of about 0.03 m/s, the thickness of the removed concrete layer is on an average about 1 mm, but can vary from 0.5 to 1.5 mm. At a few individual points, a thickness of up to 4 mm can be obtained. In comparison with the corresponding concrete that has not be flame-cleaned, the flame-cleaned exhibits about the same bond to epoxy resin adhesives, whereas its bond to cement paste is considerably better. The measurements and observations which has been made in the tests seem to indicate that flame cleaning does not produce any deleterious effects. The temperatures which can cause damage to concrete, i.e., over 200 to 250 degree C, are reached only in the uppermost layer, about 2 mm in thickness. Flame cleaning can reduce the modulus of rupture of the concrete in the surface layer. No cracks have been detected by visual inspection. Experience has shown that the very fine cracks which might have caused the slight reduction in the modulus of rupture do not give rise to any decrease in the resistance of frost action.

  • Corporate Authors:

    Cement and Concrete Research Institute

    Drottning Kristinas Vaeg 26
    Stockholm 70,   Sweden 
  • Authors:
  • Publication Date: 1975

Media Info

  • Features: Figures; Photos; References;
  • Pagination: 6 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00141539
  • Record Type: Publication
  • Report/Paper Numbers: CBI 15:75
  • Files: TRIS
  • Created Date: Nov 17 1976 12:00AM