The paper compares the performance of concrete pavements of two stretches of autoroute, the Albacete and La Roda by-passes, located in central Spain. This part of the country has wide-ranging thermic variations, both between summer and winter as well as between day and night at certain times of the year. Both pavements can be considered carbon copies of one another because they are so close to one another (30 kilometers), and because they were opened at almost the same time (Albacete: July 1987 - La Roda: June 1988), because they support hte same amount of traffic (some 1500 trucks per direction per day), and because they share the same project features (one-way mass concrete road surfaces, whose thickness ranges from 23 to 27 cm, with unfastened skewed joints, on top of a thin layer of concrete). The most significant difference between the two stretches of road is the length of the concrete slabs: between 3.7 and 5 metres for the slabs on the Albacete, and between 3.4 and 4.5 metres for La Roda. This major separation of the joints may explain the very different performance of each stretch of road: whereas the Albacete segment has over 25% cracked slabs, the figure for La Roda is 6%. On the other hand, the Albacete by-pass has a very marked correlation between the length of the concrete slabs and the percentage of cracked slabs. These cracks may be the result of the combined effect of traffic loads and temperature variations. (A)
Samenvatting