MULTI-SCALE MICROSTRUCTURAL MODELING OF CONCRETE DIFFUSIVITY: IDENTIFICATION OF SIGNIFICANT VARIABLES

In this research, a multi-scale microstructural computer model is applied to computing the chloride diffusivities of concretes with various mixture proportions and projected degrees of hydration. A fractional factorial experimental design has been implemented to study the effects in the model of seven major variables: water-to-cement (W/C) ratio, degree of hydration, aggregate volume fraction, coarse aggregate particle size distribution, fine aggregate particle size distribution, interfacial transition zone thickness, and air content. Based on this experimental design, W/C ratio, degree of hydration, and aggregate volume fraction have been identified as the three major variables influencing concrete diffusivity in the model. Following identification of the significant variables, a response surface design has been executed and least squares regression used to develop a simple equation for predicting chloride ion diffusivity in concrete based on these three parameters. This simple equation essentially summarizes the complicated simulations involved in computing the model response. Simulation have been conducted to examine the extent of the surface layer in cast-in-place concrete, where the local aggregate volume fraction near the surface is less than that to be found in the bulk of the concrete.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/3528769
• Corporate Authors:

  American Society for Testing and Materials (ASTM)

  100 Barr Harbor Drive, P.O. Box C700
  West Conshohocken, PA  United States  19428-2957
• Authors:
  • Bentz, D P
  • Garboczi, E J
  • Lagergren, E S
• Publication Date: 1998-6

Language

• English

Media Info

• Features: Figures; References;
• Pagination: p. 129-139
• Serial:
  • Cement, Concrete and Aggregates
  • Volume: 20
  • Issue Number: 1
  • Publisher: American Society for Testing and Materials (ASTM)
  • ISSN: 0149-6123
  • Serial URL: http://journalsip.astm.org/JOURNALS/CEMENT/cca_home.html

Subject/Index Terms

• TRT Terms: Chloride content; Concrete tests; Diffusivity; Durability; Microstructure; Performance tests; Variables
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00758805
• Record Type: Publication
• Files: TRIS
• Created Date: Jan 20 1999 12:00AM