Crack Initiation and Propagation in the Continuously Reinforced Pavement of the Zuidtangent

In the period 1996 — 2001 the ”Zuidtangent" was designed and constructed. The "Zuidtangent" is situated between Haarlem and Amstelveen, just south of Amsterdam (The Netherlands). The "Zuidtangent" is designed as a special purpose road connection for public transport and plays a major role in the accessibility of the Schiphol airport by reducing the passenger (car) traffic on the main road network around the airport. The "Zuidtangent" is designed as a hybrid pavement structure, on which two transportation systems can be based. At this moment only the necessary means are applied for operation of a high quality bus system. As such one can see the pavement structure as an over-designed continuously reinforced concrete pavement structure. But, the design makes it possible to refurbish the pavement structure to light-rail use. In designing the pavement structure this dual use has put extra constraints on the design and building process. In the design phase it was discovered that no experience existed with this kind of hybrid pavement structure. Especially the development of cracking (typical of continuously reinforced concrete pavements) could only be predicted by largely untested theoretical design models. After construction of parts of the pavement structure it was discovered that some of the applied assumptions were not valid. This led to the development of uncontrolled cracking and/or wider cracking than allowed in some sections. This paper pays special attention to the design models and the applied assumptions. From the experiences obtained in the "Zuidtangent" project recommendations are made for future projects.