Thickness and type of asphalt overlay

The thickness of the asphalt overlay in the case of CRCP is recommended to be 30 mm (minimum) to 40 mm (maximum). 

The type of asphalt is usually asphalt concrete for very thin layers in accordance to CEN EN 13108-2 (2008). 

The thickness of the asphalt layer in the case of CRCB is recommended to be at the minimum, 100 mm (the minimum value is normally used). This overlay usually consists of a binder course of dense asphalt concrete (CEN EN 13108-1 2008) with a surfacing layer of 30 mm. 

If a porous asphalt (CEN EN 13108-7 2008) surface course is used over CRCB, it must be modified with a polymer or fibre additive and laid over a dense binder course. The porous asphalt should be 50 mm thick over a 90 mm binder course or 50 mm thick over a 60 mm binder course with the CRCB thickness increased by 10 mm. 

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