Pre-coated chippings in HRA roads – SROH requirements
There is now a considerable increase in interest around pre-coated chipping requirement for spread rate relating to street-works conformance. It usually arises from concerns raised as part of regular or statutory inspection regimes undertaken by relevant or local authorities.
The SROH clearly determines what should be expected of newly reinstated HRA in carriageway where pre-coated chippings are applied and clearly determines this under S6.4.7(2) as follows:
“Where pre-coated chippings are to be embedded into a road surface, they shall be spread to give a chipping density reasonably matching that of the existing surface, notwithstanding the requirements for surface texture specified in Section S2.6”
It is paramount to ensure that pre-coated chipping density should reasonably match that of the existing adjacent road as texture depth and/or skid resistance may be severely compromised as a result.
The images below will show new reinstatement having less than 10% of pre-coated chippings as compared to existing road surface.
New reinstatement Existing adjacent road surface