THE PROPERTIES OF CHERT AGGREGATES IN RELATION TO THEIR DELETERIOUS EFFECT IN CONCRETE

THE ULTIMATE OBJECTIVE OF THIS STUDY WAS TO CLASSIFY THE CHARACTERISTICS OF CHERTS FOUND IN MICHIGAN GRAVEL DEPOSITS AND TO DETERMINE THE INDIVIDUAL CHARACTERISTICS OF PRIMARY IMPORTANCE IN CAUSING THE DELETERIOUS EFFECTS OF THE CHERTS WHEN USED AS AN AGGREGATE COMPONENT IN CONCRETE. THE INITIAL IDENTIFICATION, OR CLASSIFICATION OF THE CHERTS, WAS DONE ON THE BASIS OF APPEARANCE. EACH CHERT TO BE USED IN THE STUDY WAS CLASSIFIED INTO ONE OF THE FOUR APPEARANCE GROUPS SELECTED TO BEST DESCRIBE IT. MEASUREMENTS AND TESTS CONSISTING OF SPECIFIC GRAVITY, 24-HOUR AND 20-DAY ABSORPTIONS, DEGREE OF SATURATION, EFFECTIVE POROSITY, PORE SIZE DISTRIBUTION, PERMEABILITY, LONGITUDINAL PULSE VELOCITY, TENSILE STRENGTH, CHEMICAL, DTA, AND X-RAY ANALYSIS, MICROSCOPIC EXAMINATION, AND BOTH CONFINED AND UNCONFINED FREEZING AND THAWING TESTS OF DURABILITY WERE CONDUCTED. TESTS FOR INDICATIONS OF ALKALI-REACTIVITY WERE MADE, AND THE RELATIONSHIP BETWEEN CHERT PARTICLE SIZE AND FREEZE-THAW DURABILITY WAS TESTED BY FREEZING AND THAWING SATURATED CHERTS OF FOUR SEPARATE SIZE CLASSES IN MORTAR CYLINDERS. THIS LATTER TEST INDICATED NO APPARENT RELATIONSHIP EXISTS. NO ONE PROPERTY WAS FOUND TO DISCRIMINATE BETWEEN DELETERIOUS AND DURABLE CHERTS. HOWEVER, EXPERIMENTAL PROCEDURES AND STATISTICAL ANALYSIS HAVE ESTABLISHED THAT SEVERAL PROPERTIES SHOW PROMISE FOR SUCH DISCRIMINATION IF USED IN CONJUNCTION WITH ONE ANOTHER. ON THE BASIS OF THIS STUDY THE MOST PROMISING TESTS CAN BE DEVELOPED. /AUTHOR/

• Supplemental Notes:
  • Final Rept, PROJECT R-121, 122 PP
• Corporate Authors:

  Michigan Technological University, Houghton

  Institute Mineral Research
  Houghton, MI  United States  49931
• Authors:
  • Michaels, E L
  • Volin, M E
  • Ruotsala, A P
• Publication Date: 1965-7

Subject/Index Terms

• TRT Terms: Absorptivity; Cherts; Classification; Concrete; Deleterious materials; Durability; Freeze thaw tests; Impacts; Measurement; Permeability; Physical distribution; Pores; Porosity; Properties of materials; Size; Specific gravity; Tensile strength; Testing; X ray analysis
• Uncontrolled Terms: Pores
• Old TRIS Terms: Effective porosity
• Subject Areas: Freight Transportation; Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00217550
• Record Type: Publication
• Files: TRIS
• Created Date: Sep 18 1994 12:00AM