PUMPING OF HIGHWAY AND AIRFIELD PAVEMENTS by

This paps? presents the results of a study of pumping of rigid pavements- A literature search was conducted on present and past experiences of state highway departments and various governmental agencies relative to the pumping proble&o A study was made of the mechanics of pumping of rigid pavements-Surveys were made of highway pavements in Indiana constructed with and without granular bases as well as of 15 air bases* The report is divided into three parts, namely (1) a review of pumping of highway pavements built directly on natural subgrades, (2) performance of rigid highway pavements built on granular bases 9 and (3} a study of pumping of airfield aprons, taxiways and runways* Data obtained from this study have indicated that performance of rigid highway pavements built with granular bases is greatly influenced by gradation of the granular base as well as amount ©f traffic ° Correla-tions are presented which show that pavement distress as evidenced by restraint and transverse cracks is due to "blowing " of bases and that this in turn results on roads carrying high volumes of truck traffic and where poorly graded bases are used * Base courses with drains have shown better performance than those without drains although constructing poorly graded bases through the shoulder for drainage was found to be ineffective for those roads surveyed^ Pumping on airfield pavements was found to be restricted primarily Digitized by the Internet Archive in 2011 with funding fro