EFFECTS OF CONSTRUCTION CURLING ON CONCRETE PAVEMENT BEHAVIOR

Numerous factors can cause jointed plain concrete pavement (JPCP) slabs to develop a permanent upward curled shape (concave up) even when the slabs are not subjected to any temperature gradients. These factors include the temperature gradient locked into the slabs during construction (the temperature gradient at the time of concrete hardening), differential shrinkage, and moisture gradient. Pavement design features such as joint spacing, dowels, and base type, and material properties such as thermal coefficient and shrinkage characteristics affect the magnitude of construction curling. This paper illustrates the effects of construction curling on critical stresses in JPCP and the consequent effects on slab cracking. The effects of construction curling on pavement deflections and surface profile are also discussed. Also presented is a procedure for estimating the magnitude of construction curling based on curling deflections monitored over a range of temperature conditions. Field data from I-80 Pennsylvania are presented to illustrate the effects of construction curling and the procedure for estimating the magnitude of construction curling.