DEGRADATION OF LIMESTONE AGGREGATES DURING CONSTRUCTION
THERE IS GROWING EVEIDENCE THAT THE STABILITY OR STRENGTH OF GRANULAR BASES IS NOT DIRECTLY RELATED TO GRADATION, DENSITY, OR PERCENTAGE OF THEORETICAL SOLID VOLUME. UNDER THESE CIRCUMSTANCES, QUESTION ARISES AS TO THE IMPORTANCE OF CONTROLLING GRADATION AND COMPACTION IN CONSTRUCTION. THE SAME EVIDENCE INDICATES THAT THE HARDNESS OR STRENGTH OF THE AGGREGATE PARTICLES MAY BE THE CONTROLLING FACTOR. EVEN SO, IF OVERSTRESSED THE BEARING POINTS WILL CRUSH UNTIL SUFFICIENT BEARING AREAS ARE PRODUCED TO WITHSTAND THE STRESS; THIS IS ACCOMPANIED BY VOLUME CHANGE AND DEGRATION. IT CAN BE INFERRED THAT LOAD-INDUCED DEGRADATION PROCEEDS TO A STABLE STAGE. IT HAS BEEN ARGUED AT TIMES THAT GRADATION AND DENSITY ARE REDUNDANT REQUIREMENTS, AND THAT GRADATION REQUIREMENTS SHOULD BE WAIVED IF THE DENSITY IS ACHIEVED IN THE END PRODUCT. INDEED, THE POINT OF TESTING AND ACCEPTANCE WITH RESPECT TO DENSITY IS ON THE ROAD FOLLOWING COMPACTION. IF GRADATION CONTROL IS DEFERRED TO THIS POINT AND DENSITY IS ACHIEVED, A DILEMMA EXISTS. IF NEITHER DENSITY OR GRADATION REQUIREMENTS ARE MET IN THE END PRODUCT, UPSTREAM CONTROL OF THE GRADATION WOULD HAVE FOREWARNED OF THE PROBLEM. THE PRESENT STUDY WAS UNDERTAKEN TO DETERMINE WHETHER AND TO WHAT EXTENT CERTAIN PROPERTIES (PARTICULARLY GRADATION) OF KENTUCKY LIMESTONES USED IN BASE CONSTRUCTION CHANGED DURING THE CONSTRUCTION PERIOD. TWELVE CONSTRUCTION PROJECTS WERE USED IN THE PROGRAM. SAMPLES OF DENSE GRADED AGGREGATE WERE TAKEN AT THE PUGMILL, BEFORE SPREADING ON THE ROAD, AFTER SPREADING, AND AFTER COMPACTION. LABORATORY GRADATION ANALYSIS WAS PERFORMED ON ALL SAMPLES; LESS FREQUENTLY, LARGER SAMPLES WERE TAKEN AT THE PUGMILL AND AFTER SPREADING AND SUBJECTED TO A SPECIFIC GRAVITY TEST, A DEGRADATION TEST, AND ATTERBERG LIMIT ANALYSIS. ANALYSIS-OF- VARIANCE COMPUTER PROGRAMS WERE WRITTEN. ON THE WHOLE THE KENTUCKY LIMESTONES---WHICH ARE VERY HARD, HIGH-QUALITY AGGREGATES---EXHIBITED NO SIGNIFICANT DEGRADATION UNDER CURRENT CONSTRUCTION PRACTICES.
- Record URL:
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Supplemental Notes:
- RES REPT 324 APPS
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Corporate Authors:
Kentucky Department Highways
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Authors:
- Deen, R C
- Southgate, H F
- Publication Date: 1972-3
Media Info
- Features: References; Tables;
- Pagination: p. 1-13
Subject/Index Terms
- TRT Terms: Aggregates; Analysis of variance; Computer programs; Construction; Dense graded aggregates; Limestone aggregates; Materials tests; Quality control; Road construction; Statistical quality control
- Uncontrolled Terms: Aggregate testing
- Old TRIS Terms: Degradation (Aggregate); Quality control testing
- Subject Areas: Construction; Data and Information Technology; Geotechnology; Highways;
Filing Info
- Accession Number: 00217911
- Record Type: Publication
- Files: TRIS, STATEDOT
- Created Date: Feb 3 1973 12:00AM