The construction of this linear infrastructure, which enables wheeled vehicle traffic in optimum conditions of safety and comfort, is a complex task. Most road surfaces are manufactured from bituminous mixtures formed by a mixture of stones selected according to size and quality (aggregate) and bitumen or asphalt, which the binder that holds said stones together. At a basic level of construction, a road consists of laying down successive layers of stone materials with different properties and resistances. At construction level, there will be differences depending on whether the road will be located in a mountainous area or if terrain must be added (embankments). The greatest enemy of these infrastructures is the extremely heavy load of heavy vehicles and climatic agents.
The surface or pavement is that configured by the final road layers, those which are in direct contact with vehicle tires and which suffer greater wear over time.
The continuous weathering of the bitumen that forms the road causes oxidation by UV rays from the sun and by contact with the oxygen in the air. This situation makes the surface lose its lightest fractions, stiffening and therefore losing its flexibility and adhesion to the aggregates in the mixture.
Additionally, the use of materials treated with cement in some surface layers give rise to retraction, setting, or thermal cracks.
All the products mentioned are black, viscous products with a very complex composition that can be grouped under the name hydrocarbon binders. The differences can be found in their origin since, while bitumen is a product derived from crude oil, pitches and tars are products derived from coal, and asphalt is a product of natural origin that can be found in a free state or impregnated with porous minerals (asphaltic rocks).
Knowing the differences between these products, it is important to highlight that the advantages of oil derivatives make it by far one of the most widely used element worldwide.
As far as we know, the first time asphalts were recycled was in the twenties. After the Second World War their use became more common in the UK, and the same happened in the USA in the seventies as a result of the oil crisis. In Spain, asphalt recycling became more common in the nineties, incorporating a range of techniques aimed at achieving the same objective.
At Repsol we have developed REJUV bitumens and emulsions that take full advantage of already degraded materials. They are specific designs that include all the current techniques: onsite cold recycling, or hot, warm, or cold recycling of bituminous mixtures at the manufacturing plant.
The EC Mark for binders is a mandatory requirement for the free sale of binders in the European Union. This responsibility of the manufacturer consists of a series of specifications and tests, in addition to production control requirements. The EC Mark encompasses the entire production process from the receipt of raw materials to the procurement of the final product, including factory operating conditions and laboratory tests, without forgetting the calibrations and maintenance plans of all the equipment involved in both the plant and laboratory. It has been mandatory for bitumen, hard bitumen and cationic bituminous emulsions since January 1st, 2011. In the case of modified bitumen, the date was January 1st, 2012. The EC mark symbol must comply with the general principles established in Article 30 of Regulation (EC) No. 305/2011 and should be placed in a visible, legible and indelible place.
The manufacturer will issue a declaration of features of each product, assuming responsibility for the compliance of the construction product with the declared characteristics.