Construction on Toll Highway A-7 which runs between Tarragona and Valencia, on the Mediterranean coast of Spain, began in the early 1970s. Part of the road had a concrete pavement built according to the then California technique (average length of flagstone: 5m, gravel/cement base with low cement content, non-stabilized hard shoulder). The structural capacity of the pavement was sound, especially after an injection of cement grout to stabilize the flagstones and fill the potholes, but due to cracking and unevenness in one stretch of the pavement, measures had to be taken to improve user comfort and prolong the operational life of the pavement. The solution was to place an asphalt overlay, especially studied to prevent surface reflection of the joints and cracks, on pavement. In the spring of 1993, a total of 33 km of road were paved in the Castellon region followed by 10 km in 1994. To date, only a few cracks have appeared on the surface. Prior to placing the asphalt layers, grout was injected into the entire outside lane and all joints and cracks in existing pavement were sealed. The anti-crack complex was made up of: a regulating course with conventional fine grain asphalt mastic on the concrete with a tack coat of modified emulsion ESR-205. (A)
Abstract