PERCOLATION AND PORE STRUCTURE IN MORTARS AND CONCRETE

The cement paste in concrete and mortar has been shown to have a pore size distribution different than that of plain paste hydrated without aggregate. For mortar and concrete, additional porosity occurs in pore sizes larger than the plain paste's threshold diameter as measured by mercury intrusion. Based on the assumption that these larger pores are essentially present only in the interfacial zones surrounding each aggregate, an experimental program was designed in which the volume fraction of sand in a mortar was varied in a systematic fashion and the resultant pore system probed using mercury intrusion porosimetry. The intrusion characteristics were observed to change drastically at a critical sand content. Similar results are observed for a series of mortar specimens in which the cement paste contains 10% silica fume. To better interpret the experimental results, a hard core/soft shell computer model has been developed to examine the percolation characteristics of these interfacial zone pores. Using the model, interfacial zone percolation in concretes is also examined. Finally, the implications of interfacial zone percolation for transport properties and durability of mortar and concrete are discussed. (A)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00088846
• Corporate Authors:

  Pergamon Press, Incorporated

  Headington Hill Hall
  Oxford OX30BW,    
• Authors:
  • WINSLOW, D N
  • Cohen, M D
  • Bentz, D P
  • Snyder, K A
  • Garboczi, E J
• Publication Date: 1994

Language

• English

Media Info

• Features: References;
• Pagination: p. 25-37
• Serial:
  • Cement and Concrete Research
  • Volume: 24
  • Issue Number: 1
  • Publisher: Elsevier
  • ISSN: 0008-8846
  • Serial URL: http://www.sciencedirect.com/science/journal/00088846

Subject/Index Terms

• TRT Terms: Cement paste; Concrete; Durability; Mix design; Permeability; Porosity; Sand
• ITRD Terms: 4767: Cement paste; 4755: Concrete; 5910: Durability; 4714: Mix design; 5921: Permeability; 5938: Porosity; 4105: Sand
• Subject Areas: Design; Geotechnology; Materials;

Filing Info

• Accession Number: 00662467
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Jul 28 1994 12:00AM