Field investigation of the early-age curling behaviour and performance of extra-wide CRCP on semi-rigid base

This study investigates the early-age daily curling behaviour of extra-wide continuously reinforced concrete pavement (CRCP) on a semi-rigid base, focusing on the effect of random transverse cracks and transverse sawcut induced active cracks. Two test sections in Wuhan, China, were selected to monitor concrete strain variations before and after transverse crack occurrence and to assess deflection distribution under temperature gradients with crack survey. Results indicate significant differences in transverse and longitudinal curling at slab centre and edge, with transverse cracks notably affecting strain variation. Additionally, deflection distributions under different temperature gradients are closely related to daily curling. Early-age curling is pronounced within 2 meters of the free edge, while sawcut induced active cracks significantly enhance curling. The emergence of longitudinal and irregular cracks is associated with curling behaviour. Thus, extra-wide CRCP on a semi-rigid base without longitudinal sawcut joints is not recommended due to the risk of abnormal early-age cracking.