LIMITING CRITERIA FOR THE DESIGN OF CRCP

The primary factors to consider in the thickness and reinforcement design for continuously reinforced concrete pavements are the structural response variables; crack spacing, crack width, and maximum steel stress. They plant an important role in the outcome of the pavement performance, and can be related to the major distresses common to CRC pavements. In the previous report, 177-16, the relationships between the significant input variables and the structural responses predicted by the CRCP-2 computer model were quantified using regression techniques and expressed as a set of nomographs. This set of design changes enables us to graphically predict the final crack spacing, crack width, and steel stress in CRC pavement. This report determines the design limiting criteria for these structural responses. Previous investigations of the design criteria were reviewed and the most recently developed analytical models studied. The basic procedures used to establish the design criteria included examination of the major distresses such as punchout, spalling, and steel rupture and study of correlations between these distresses and the corresponding structural responses at appropriate levels. The procedure for use of these limiting criteria in CRCP design is outlined along with a series of guidelines for the selection of CRCP design input values. (FHWA)