A SURVEY OF PUMPING IN ILLINOIS

THE AREA SURROUNDING CHICAGO WAS SELECTED FOR AN INTENSIVE PAVEMENT PUMPING STUDY TO DETERMINE THE CAUSE AND EXTENT OF PUMPING AND POSSIBLE MEANS OF PREVENTING ITS OCCURRENCE ON FUTURE PROJECTS. THE STUDY INVOLVED THE COLLECTION OF DESIGN AND CONSTRUCTION DATA FOR 78 PROJECTS, A RECONNAISSANCE SURVEY OF THE VARIOUS PROJECTS, DETAILED STUDIES OF REPRESENTATIVE PORTIONS OF EACH PROJECT, THE SAMPLING AND TESTING OF SUBGRADE SOILS, IN-PLACE DENSITY MEASUREMENTS OF SUBGRADES AND SUBBASES, TRAFFIC SURVEYS, AND THE ANALYSIS OF DATA AND OBSERVATIONS. THE ANALYSIS CONFIRMED THE FACT THAT FREE WATER MUST BE PRESENT, AXLE LOADS MUST BE HEAVY AND FREQUENT, AND THE SUBGRADE SOIL MUST BE CAPABLE OF GOING INTO SUSPENSION, TO PRODUCE PAVEMENT PUMPING. THE TEXTURE OF THE SUBGRADE DETERMINED ITS SUSCEPTIBILITY TO PUMPING. INCREASED COMPACTION GENERALLY REDUCED PUMPING. SOIL CONTAINING MORE THAN 55 PERCENT SAND AND GRAVEL (MATERIAL RETAINED ON THE NO. 270 SIEVE) WAS FOUND TO PREVENT PUMPING. FURTHERMORE, GRANULAR SUBBASES WILL PREVENT PUMPING. PROMPT AND CONTINUED PAVEMENT AND ROAD MAINTENANCE WAS ALSO FOUND TO BE EFFECTIVE IN CONTROLLING AND REDUCING PUMPING. REPEATED SUBSEALING EFFECTIVELY CONTROLLED PUMPING. /AUTHOR/

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Filing Info

  • Accession Number: 00218898
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: May 29 1972 12:00AM