IMPORTANCE OF PETROGRAPHIC ANALYSIS AND SPECIAL TESTS NOT USUALLY REQUIRED IN JUDGING QUALITY OF CONCRETE SAND

THE DIFFICULTIES ENCOUNTERED IN THE CONCRETE CONSTRUCTIONS OF A LARGE AND IMPORTANT HYDROELECTRIC PLANT ARE DESCRIBED. THE SAND AND GRAVEL AGGREGATES FROM AN APPROVED BUT PREVIOUSLY UNDEVELOPED DEPOSIT, WHEN PROPERLY PROCESSED, MET ASTM SPECIFICATION REQUIREMENTS. INVESTIGATIONS DISCLOSED THAT THE HIGH WATER REQUIREMENT AND VERY RAPID EARLY STIFFENING CHARACTERISTICS OF JOB CONCRETES WERE CAUSED BY THE SAND. DURING HANDLING AND TRANSPORTING THE SAND AND PLACING AND MIXING THE CONCRETE, THE SAND SUFFERED SEVERE DEGRADATION, THE VERY HIGH PERCENTAGE OF FINES THUS CREATED CONTAINED AN UNUSUALLY LARGE PROPORTION OF MONTMORILLONIOD /SWELLING/ CLAY MINERALS. IT APPEARS THAT SIMILAR DIFFICULTIES ON OTHER JOBS ARE NOT UNCOMMON. A SPECIAL ATTRITION TEST EMPLOYED IN A LATER VERY EXTENSIVE LABORATORY INVESTIGATION IS DESCRIBED. THIS TEST OR A SIMILAR ONE FOR SANDS IS RECOMMENDED, IN ADDITION TO THE STANDARD ASTM REQUIREMENTS. THE IMPORTANCE OF A THOROUGH PETROGRAPHIC EXAMINATION OF SAND FROM A POTENTIAL SOURCE OF CONCRETE AGGREGATES, INCLUDING THE NATURE OF THE FINES CREATED BY THE SPECIAL ATTRITION TEST, IS STRONGLY AFFIRMED. /AUTHOR/

• Supplemental Notes:
  • Vol 2, No 3, PP 461-486, 7 FIG, 4 TAB
• Authors:
  • Davis, R E
  • Mielenz, R C
  • Polivka, M
• Publication Date: 1967-9

Media Info

• Serial:
  • Journal of Materials
  • Publisher: American Society for Testing and Materials (ASTM)

Subject/Index Terms

• TRT Terms: Concrete aggregates; Concrete construction; Fines (Materials); Geological surveying; Gravel; Petrography; Sand; Swelling; Testing; Turnover
• Uncontrolled Terms: Attrition; Stiffening
• Old TRIS Terms: Petrographic investigations
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00217557
• Record Type: Publication
• Files: TRIS
• Created Date: Jan 8 1994 12:00AM