Ten years of hydraulic concrete pavement of the Mediterranean 75 highway

The highway Tarragona-Valencia-Alicante, 375 km along che Spanish easccoasc, has 240 km of concrete pavement. It is being used, in sections, since June 1974. Due co the similar climate and geology of California (U.S.A.) and che Spanish Levante, in the initial design of 1972 Californian technology was mainly used. The election of the type of concrete was made in order to the foreseen axle loads and co guarantee Long-life duration and low coSts of maintenance. The design advanced in order co che evolution of the pavement in use and che technical developments in other countries, especially in the following aspects: - lateral drainage of the slabs - higher resistance of the base to erodability: - higher quantity of cement in the cement treated bases - bases of lean concrete - change of che cross-sections of the slabs: from rectangular of 25 cm of depth to crapezoidal of 28-24 cm - smaller size of che slabs (actually the highest lenath is 4.60 m). The performance of the pavement in its longitudinal cexture is excellent. A slight tendency of cracking of the 6 m long slabs has been noticed, with stepping of slabs in some localised parts, without lateral drainage and low content of cement of the cement treated base, reaching values up to 2 mm.