ASSESSMENT OF LOAD TRANSFER ACROSS JOINT IN UNDOWELED JOINTED CONCRETE PAVEMENT USING THE FALLING WEIGHT DEFLECTOMETER

The joints in concrete pavements provide a control against transverse or longitudinal cracking in the slab, which may be caused by temperature or moisture variation during or after hydration. Without control of cracking, random cracks may cause more serious distresses and result in structural or functional failure of a pavement system. However, the joint itself, intended to control cracks, may cause distresses such as joint spalling, water pumping, faulting, corner breaks, and blow-up in joints, due to its inherent weakness in structural integrity. Thus, the load transfer capacity in joints is very important for serviceability and durability. Due to these distresses at joints, many maintenance costs are necessary in order to repair and maintain structural and functional integrity. Thus, joints should be designed and constructed by insuring a proper load transfer capacity at joints for serviceability and durability of pavement systems. Many research results were reported on the reasons of joint distresses. Bad load transfer efficiency is pointed out as one of the main causes for distresses at joints. When the subbase has good stiffness and the base is layered by lean concrete, dowel bars may be omitted for cost reasons, still keeping the load transfer capacity and preventing distresses at joints. A series of field applications without inserting dowel bars at JCP were made at Chungbu Highway, Honam Highway and 88 Highway. This research focused on the investigation of the behavior of undoweled JCP and on the necessity for dowel bars in pavement systems based on lean concrete through a series of field FWD tests. (a) For the covering entry of this conference, please see ITRD abstract no. E204151.