EXPANDED HOT CLAY MIX STUDY AND DISCUSSION

THIS IS PART ONE OF A TWO PART FINAL REPORT ON EXPANDED CLAY HOT MIX, TO (1) EVALUATE THE USE OF VARIOUS EXPANDED CLAY MIXTURES UNDER HIGH TRAFFIC COUNTS; (2) ACCUMULATE THROUGH EXPERIENCE AND TESTING, SUITABLE INFORMATION ON THE PHYSICAL PROPERTIES OF THE EXPANDED CLAY AGGREGATES AND MIXTURES, FOR RECOMMENDING ADEQUATE TESTING AND CONTROL PROCEDURES ON EXPANDED CLAY MIXTURES; (3) PREPARE A SUITABLE EXPANDED CLAY HOT MIX SPECIFICATION. IN ORDER TO EVALUATE EXPANDED CLAY HOT MIX, FOUR CONTROL SECTIONS, CONSISTING OF A STANDARD TYPE 1 GRAVEL HOT MIX, WERE CONSTRUCTED AS A BASIS OF COMPARISON WITH SIXTEEN EXPANDED CLAY HOT MIX SECTIONS, VARYING IN AGGREGATE PROPORTIONS, MINERAL FILLER AND ASPHALT CONTENT. THE EVALUATION CONSISTED OF PHYSICAL PROPERTIES OF EXPANDED CLAY MIXED AT THE PLANT, THE LAYDOWN AND COMPACTION OPERATION IN THE FIELD, TESTING OF ROADWAY CORES ORIGINAL AND ONE YEAR AFTER CONSTRUCTION, ROUGHNESS, SKID RESISTANCE, AND PRESENT SERVICEABILITY INDEX MEASUREMENTS ON THE ROADWAY AT VARIOUS TIME INTERVALS AFTER COMPLETION AND VISUAL OBSERVATION OF THE GENERAL APPEARANCE OF THE ROADWAY AFTER BEING SUBJECTED TO TRAFFIC. EXPANDED CLAY HOT MIX APPEARS TO BE A SATISFACTORY MATERIAL FOR USE IN HOT MIX PAVEMENTS. HOWEVER, THERE ARE SOME PROBLEMS TO BE CONSIDERED WHEN TESTING EXPANDED CLAY MIXES FOR THEIR PHYSICAL PROPERTIES. THE PHYSICAL PROPERTIES NORMALLY INCLUDE SUCH TESTS AS SPECIFIC GRAVITIES, PER CENT VOIDS, VOIDS FILLED WITH ASPHALT, VOIDS IN THE MINERAL AGGREGATE, EXTRACTED GRADATIONS AND PER CENT OF LABORATORY GRAVITY. ALL OF THESE TESTS ARE DETERMINED BY WEIGHT MEASUREMENTS AND BECAUSE OF THE WEIGHT DIFFERRENCES IN TWO OF THE COMPONENTS, EXPANDED CLAY AND SAND, THIS PRESENTS SOME PROBLEMS THAT DO NOT EXIST IN OTHER MIXTURES WHERE THE SPECIFIC GRAVITIES OF ALL THE AGGREGATE COMPONENTS ARE APPROXIMATELY EQUAL. THE INTENT OF THIS STUDY IS TO PRESENT THE PROBLEMS THAT MAY BE ENCOUNTERED IN THE CONTROL OF EXPANDED CLAY MIXES AND TO RECOMMEND A SUITABLE SOLUTION TO SOLVING SUCH PROBLEMS, AS WELL AS, DEVELOPING SUITABLE MIX DESIGN CRITERIA AND SPECIFICATIONS. /AUTHOR/

• Supplemental Notes:
  • Vol 39, pp 297-344, 21 FIG, 5 TAB, 10 PHOT, 2 REF, 5 APP
• Authors:
  • Arena, P J
• Conference:
  • Association of Asphalt Paving Technologists Proc
• Publication Date: 1970

Subject/Index Terms

• TRT Terms: Bituminous pavements; Expanded clay aggregates; Hot mix asphalt; Lightweight aggregates; Pavement performance
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00211659
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 25 1971 12:00AM