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COLOURED ASPHALT AGGLOMERATE The main application of a black asphalt or bitumen is the agglomeration of aggregates and fillers to be used on the construction of roads. The colouring of the asphalt agglomerate is possible; we can achieve visually pleasant pavements in the implementation of parks, sidewalks, bike lanes, etc. This is an interesting and competitive option face to the black asphalt agglomerate or other constructive solutions. However, to beat the black colour of the agglomerate can only be successfully achieved pigmenting with red synthetic iron oxides with high colour strength. Other pigments such as green, yellow, white, blue, etc., are too poor even if we lead them to saturation dosage. In these specific cases it will be necessary to use a clear synthetic binder. The intensity of the colour obtained using the same dosage, will depend on the specific surface area provided by the aggregates and agglomerate fillers. Likewise, a closed granulometric curve will give less surface cavities and will have an optical perception more intense. A conventional asphalt agglomerate is approximately composed with: 90% aggregates 5% fillers (aggregates<80μ) 5% bitumen In any case it would be wise to pay attention to the grain size distribution because an excessive specific surface could require a bigger quantity of binder (bitumen) and could determine the final colour. Therefore, it is always advisable to do some dosing tests on pigments to match the specific composition of aggregate and filler. Black asphalt agglomerate (not pigmented) Black asphalt agglomerate pigmented with iron oxide ChromaFer 1330 at a rate of 5% dosage.
