Active Crack Control for Continuously Reinforced Concrete Pavements

Continuously reinforced concrete pavements (CRCP) traditionally have been allowed to crack naturally. This type of passive crack control has resulted in nonuniform crack spacing, which has led to premature distress development. Although the accuracy of the mean crack spacing prediction has greatly improved, punchout and spalling distresses on CRCP have been found to occur primarily at locations of small crack spacing, divided cracks, cluster cracks, and Y-cracks. The findings of previous research results on active crack control for CRCP in Texas are presented, along with the results from recent full-scale test sections constructed at the University of Illinois. The active crack control process used two systems: automated tape insertion and early entry saw cut. Active crack control was found to eliminate crack meandering, Y-cracks, divided cracks, and cluster cracking. The active crack control sections also propagated 90% of the cracks in the first month after construction, whereas the passive crack sections took 18 months to reach a similar number of cracks. Both active and passive cracks propagated only in the winter months. Crack opening measurements showed that active crack control resulted in slightly smaller movements relative to the natural crack sections. By using active crack control on CRCP, more uniform, straighter, and early-age transverse cracks result, which will increase the expected service life of CRCP.