CONCRETE PAVEMENT REPLACED IN 1-1/2 HOURS

IN ORDER TO FIND A LASTING CONCRETE PAVEMENT REPAIR THAT WOULD REDUCE LANE CLOSURE TIME TO A MINIMUM, MICHIGAN HAS DEVELOPED TWO PROCEDURES TO DATE: PRECAST SLAB REPAIRS, AND REPAIRS WITH FAST-SETTING CONCRETE. A PREVIOUSLY SAWED 10 BY 12-FOOT CONCRETE AREA CAN BE REMOVED AND REPLACED WITH A PRECAST SLAB AND OPEN TO TRAFFIC IN APPROXIMATELY 1-1/2 HOURS. A REPAIR WITH FAST-SETTING CONCRETE CAN BE SUBJECTED TO TRAFFIC ABOUT SIX HOURS AFTER POURING. THE LIMITS OF THE FAILED AREA ARE SAWED FULL-DEPTH AND THE CONCRETE IS REMOVED WITHOUT DISTURBING THE EXISTING BASE. JOINTS BETWEEN THE OLD AND NEW SLAB MAY BE DOWELED OR UNDOWELED, AND CAN BE EITHER CONTRACTION OR EXPANSION JOINTS. EVALUATION TO DATE INDICATES THAT THE REPAIRS ARE PERFORMING SATISFACTORILY. (AUTHOR)