CORRECTING PAVEMENT PUMPING BY MUD JACKING-INDIANA

A SECTION OF ROAD WAS SELECTED FOR OBSERVATION IN WHICH VARIOUS MIXES OF SOIL, CEMENT, AND BITUMINOUS MATERIALS WERE TO BE FORCED UNDER SOME OF THE SLABS THAT HAD SETTLED DUE TO PUMPING ACTION. FIFTY PUMPING JOINTS WERE TREATED BY MUD-JACKING. CONCLUSIONS INCLUDED: (1) PUMPING REQUIRES THREE CONDITIONS, A SUBGRADE CONSISTING OF A RELATIVELY PLASTIC AND IMPERVIOUS CLAY ON SILTY-CLAY SOIL, HEAVILY LOADED VEHICLES, AND A HIGH MOISTURE CONTENT; (2) ALL EXPERIMENTAL SUBGRADE TREATMENTS HAVE SUCCEEDED IN MINIMIZING OR PREVENTING PUMPING; (3) TREATMENT BY MUDJACKING REDUCED THE EXPECTED INCREASE IN 2-YEAR CRACKS; (4) MUDJACKING WAS SUCCESSFUL IN REDUCING THE AVERAGE SETTLEMENT OF SLABS AT PUMPING JOINTS; (5) DATA IS TOO LIMITED TO RECOMMEND MUDJACKING OPERATIONAL PROCEDURES.