INTERIM REPORT ON THE USE OF EXPANDED SHALE AND PRECOATED LIMESTONE AS COVERSTONE FOR SEAL COAT AND SURFACE TREATMENTS

THE RESULTS OF LABORATORY AND FIELD STUDIES ON THE USE OF ONE PRODUCERS CALCINED SHALE AS THE COVERSTONE FOR SEAL COAT AND SURFACE TREATMENT CONSTRUCTION ARE PRESENTED. LABORATORY STUDIES INCLUDE THE FOLLOWING' /1/ THE INVESTIGATION OF COVERSTONE RETENTION AS AFFECTED BY THE RATE OF APPLICATION OF THE CALCINED SHALE, AND OF THE BINDER. TEST BOARDS WERE PREPARED USING SELECTED RATES OF APPLICATION OF AGGREGATE AND BINDER AND ROLLED WITH A PNEUMATIC TIRE. THE PERCENTAGE OF AGGREGATE NOT IMBEDDED WAS THEN DETERMINED. RESULTS SHOWED THAT THE PERCENTAGE OF AGGREGATE LOSS INCREASED WITH INCREASING RATES OF APPLICATION OF AGGREGATE AND DECREASED WITH INCREASING RATES OF APPLICATION OF BINDER. /2/ WINDSHIELD DAMAGE STUDIES WERE MADE WHERE AGGREGATE PARTICLES OF VARIOUS SIZES WERE SHOT FROM AN AIR GUN AT DIFFERENT VELOCITIES TO DETERMINE THE COMPARATIVE DAMAGE TO AUTOMOBILE WINDSHIELDS. THESE STUDIES SHOWED THE CALCINED SHALE TO BE POTENTIALLY FAR LESS DAMAGING THAN THE PRECOATED LIMESTONE AGGREGATE. /3/ PHYSICAL TEST CHARACTERISTICS WERE DETERMINED FOR THE CALCINED SHALE AGGREGATE, AND INCLUDED LOS ANGELES ABRASION TESTS WITH MODIFICATIONS, FREEZE-THAW TESTS AND SOUNDNESS TESTS. LOSSES IN ALL TESTS WERE RELATIVELY LOW. AGGREGATE DEGRADATION STUDIES WERE MADE ON SAMPLES OBTAINED FROM PAVEMENTS PRESENTLY IN SERVICE AND CONSTRUCTED FOLLOWING NORMAL PROCEDURES. THE DATA REPORTED THAT TIME IN SERVICE WAS NOT A SIGNIFICANT FACTOR IN CHANGING THE GRADING OF COVER AGGREGATE BUT RATHER THAT DEGRADATION WAS CAUSED MAINLY BY ROLLING DURING CONSTRUCTION. PNEUMATIC ROLLING ONLY IS RECOMMENDED.

• Supplemental Notes:
  • Texas Rr No.51-1, HPR-1/3/
• Corporate Authors:

  Texas Transportation Institute

  Texas A&M University System, 1600 E Lamar Boulevard
  Arlington, TX  United States  76011
• Authors:
  • Gallaway, B M
• Publication Date: 1964-12

Subject/Index Terms

• TRT Terms: Aggregates; Applications; Binders; Calcines; Expanded shale aggregates; Field tests; Freeze thaw tests; Laboratory tests; Loss and damage; Particles; Precoated aggregates; Retaining walls; Samples; Seal coats; Shale; Soundness test; Studies; Surface treating; Windshields
• Identifier Terms: Los Angeles Abrasion Test
• Old TRIS Terms: Air guns; Calcined shale; Cover aggregate; Physical tests; Retaining; Test boards
• Subject Areas: Geotechnology; Highways; Materials; Research;

Filing Info

• Accession Number: 00217445
• Record Type: Publication
• Source Agency: Bureau of Public Roads /US
• Files: TRIS
• Created Date: Sep 1 1994 12:00AM