Crack and seat rehabilitation on concrete pavements is the process whereby the existing concrete pavement is cracked to destroy the integrity of the slab. This cracking reduces the slab length, which reduces the thermal effect on joint movement. The seating operation is required to ensure that the pieces of slab are firmly seated intothe underlying foundation material to eliminate vertical movement. Both of these are contributing factors in the development of reflection cracking. Reduction in the amount and severity of reflection cracking in an asphalt concrete overlay is the sole design requirement of the crack and seat procedure on a rigid pavement. This paper presents the results of an analysis of seventy crack and seat projects from twelve states throughout the united states. These data were collected as part of a study funded by the federal highway administration (fhwa) of rehabilitation techniques to evaluate the parameters that affect their performance. By regression analysis of the database, models were developed that demonstrate general tendencies evident from the data concerning the performance of the crack and seat sections. This evaluation will provide the information to develop guidelines and recommendations for construction to improve their performance.This paper appears in transportation research record no. 1215, Pavement management and rehabilitation.
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