STRESS RELAXATION PHENOMENA AT EARLY TECHNOLOGICAL PHASES OF GAS-CONCRETE

This paper is an attempt to develop a rheological explanation of the mechanics of creating qualitative or nonqualitative (cracked or uncracked) porous structure in the process of hydrogen foaming of gas-concrete slurry. For this goal, the simplest rheological model of similar mortar-type slurries, the Bingham's model, was used. The foaming process and the process of technological deformation of gas-concrete slurry were approximated by a simple exponential equation. By solving the Bingham's model equation in the previously mentioned manner of deformation and taking into account the decreasing horizontal section of the cell walls, the theoretical kinetics of increase and relaxation for the tensile stresses in the cell walls during the foaming process were estimated. A comparison of the model to experimentally measured stresses was carried out, and the coincidence as well as some disagreements were discussed. The causes of noncoincidence are suggested. For more exact stress calculation in the previously mentioned foaming process, the conception must be more complicated. This work is the first approximation for this purpose.

• Record URL:
  http://www.concrete.org/Publications/InternationalConcreteAbstractsPortal.aspx.aspx?m=details&i=643
• 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:
  • Lapsa, V A
• Publication Date: 1999-7

Language

• English

Media Info

• Features: Figures; References;
• Pagination: p. 436-439
• Serial:
  • ACI Materials Journal
  • Volume: 96
  • Issue Number: 4
  • Publisher: American Concrete Institute (ACI)
  • ISSN: 0889-325X
  • Serial URL: https://www.concrete.org/publications/acimaterialsjournal.aspx

Subject/Index Terms

• TRT Terms: Cracking; Foaming agents; Gas permeability (Concrete); Hydrogen; Kinetics; Rheology; Slurry; Tensile properties
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00767851
• Record Type: Publication
• Contract Numbers: CMS-9796326
• Files: TRIS
• Created Date: Aug 27 1999 12:00AM