Distresses In CRCP Due To Horizontal Cracking: A Parameter Analysis

Abstract

Continuously reinforced concrete pavements are known for their durability and longevity as well as for the driving comfort, thanks to the absence of transverse joints. The strength and weakness of CRCP is situated in the network of fine transverse shrinkage cracks whose spacing distance and opening width are determining the pavement behaviour. The most commonly known distress is the punch-out: a fragmentation of the concrete over full depth. During the last decade, a new type of distress was encountered at Belgian worksites. It is characterised by a delamination at the level of the longitudinal reinforcement, a partial fragmentation of the pavement, mostly positioned under the wheel tracks. The first case was the worksite "N49 at Zwijndrecht", where severe distresses were observed after three years of service. An examination with the technique of ultrasonic tomography detected the presence of horizontal cracks at the level of the reinforcement. The use of recycled concrete aggregates was supposed to be the cause. A significant indicator was also the presence of widely opened cracks. In the period 2011-2018 other cases were observed in Belgium, some of them leading to early degradation and others not. Also in other countries (South-Korea, U.S., Japan, ...) distresses due to horizontal cracking were reported. Based upon observations an analysis is made of the main parameters that may cause the wide initial cracks: the use of recycled aggregates, temperature and temperature changes during construction and concrete quality. Preventative measures such as active crack control will be presented.