EFFECTS OF HIGH ALKALINITY ON CEMENT PASTES

Adding sodium hydroxide to increase the alkalinity of cement pastes is known to increase the initial rate of hydration, thereby increasing early strength. However, the effects on the microstructure and other properties are unclear. This study examines the influence of NaOH addition on the rate of cement hydration, surface area, and porosity as measured by nitrogen and drying shrinkage. While a 1M NaOH solution increases the rate of reaction prior to 1 day, hydration is retarded at later ages. The surface area is reduced when compared to samples without added NaOH, which is a reflection of a lower volume of small pores. The rate of drying shrinkage appears to be slower when NaOH is added, but the total equilibrium value is unaffected. NaOH also increases the amount of cracking during drying shrinkage.

• 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:
  • Juenger, MCG
  • Jennings, H M
• Publication Date: 2001-5

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 251-255
• Serial:
  • ACI Materials Journal
  • Volume: 98
  • Issue Number: 3
  • Publisher: American Concrete Institute (ACI)
  • ISSN: 0889-325X
  • Serial URL: https://www.concrete.org/publications/acimaterialsjournal.aspx

Subject/Index Terms

• TRT Terms: Alkalinity; Cement additives; Cement paste; Drying; Hydration; Materials in specific structural applications; Sodium hydroxide; Strength of materials
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00812020
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 25 2001 12:00AM