Recent field observations on several newly constructed continuously reinforced concrete pavements (CRCPs) in Belgium indicate that the crack pattern is characterized by low mean crack spacing (approximately 1.0 m after 2 years in service) along with a high percentage of clusters of closely spaced cracks. Field surveys also indicate that it is difficult to reduce significantly the probability of a nonuniform crack pattern–-such as closely spaced cracks, meandering, and Y-cracks–-by slightly adjusting the amount of longitudinal steel. The nonuniform crack pattern is inevitable and common in conventional CRCP. Previous experience in the United States shows that active crack control for CRCP can eliminate the cluster cracks and that a more uniform crack pattern with straight cracks can be achieved. A new partial surface notch for active crack control was proposed and adopted first in the reconstruction project of Motorway E313 in Herentals, Belgium, in 2012. The introduction of the proposed active crack control method is described in detail. The effectiveness of improving the crack pattern is demonstrated in the field investigations.
Continuously reinforced concrete pavements (CRCPs) have been used in Belgium on a large scale for more than 40 years. Under the initial standard design concept, an apparently unfavorable cracking pattern develops with a high probability of clusters of closely spaced cracks. The standard design underwent several changes addressing longitudinal reinforcement rate, depth of the reinforcement layer, presence of an asphalt interlayer, pavement thickness, concrete mix, surface finishing, and lane width. The current concept has been used since 1995, and no major distresses have occurred since then. Research was undertaken to investigate crack spacing and crack width characteristics of CRCPs under the current design concept with a focus on the influence of the differing reinforcement percentages on early-age cracking behavior of CRCPs. Several approaches were used for analysis of crack spacing, especially the probability of clusters of closely spaced cracks. Crack width data including the movement of the slab were obtained with linear variable differential transformer measurements.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.