ABNORMAL SET OF PORTLAND CEMENT CAUSES AND CORRECTIVES

ABNORMAL SET OF PORTLAND CEMENT MAY BE DUE TO DIFFERENT COMBINATIONS OF SEVERAL CAUSES. GYPSUM RECRYSTALLIZATION WAS CONFIRMED AS ONE CAUSE. THE RATE OF ETTRINGITE PRECIPITATION OF CERTAIN CEMENTS TREATED WITH ORGANIC ADMIXTURES CORRELATED WITH THE RATE OF STIFFENING OF THE MORTARS. THIXOTROPIC SET WAS DETERMINABLE ON CEMENT-BENZENE SLURRIES WITH A THIXOMETER, AN INSTRUMENT DEVELOPED FOR THE PURPOSE. THIXOTROPIC BEHAVIOR WAS INDUCED BY AERATION AT 50 PERCENT R H AND PERSISTED IN CEMENT-WATER PASTES FROM ABOUT 10 SECONDS TO OVER 11 MINUTES. THE RATE OF GYPSUM AND ETTRINGITE FORMATION WAS FOLLOWED BY DIFFERENTIAL THERMAL ANALYSIS. THE CAUSES OF AND CORRECTIVES FOR ABNORMAL SET ARE DESCRIBED. /AUTHOR/

• Supplemental Notes:
  • Rec-oce-69-2, 23 PP, 8 FIG, 2 TAB, 1 APP
• Corporate Authors:

  Bureau of Reclamation /US

  ,    
• Authors:
  • Kalousek, G L
• Publication Date: 1969-11

Subject/Index Terms

• TRT Terms: Crystallization; Differential thermal analysis; Ettringite; Gypsum; Portland cement; Sets; Thixotropy
• Old TRIS Terms: Precipitation; Recrystallization
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00213661
• Record Type: Publication
• Files: TRIS
• Created Date: Feb 24 1970 12:00AM