Road haunches: a guide to re-usable materials

This guide provides engineers with methods of repairing road haunches by re-using road materials or industrial by-products. The guidance given is based on the in-service performance of re-usable materials and recycling processes used in the foundation and structural layers of the haunch in three road trials. The performance of 22 test sections has been assessed over a period of two years in order to establish structural equivalences for the re-usable materials in terms of their engineering performance compared to that of crushed rock (Type 1) sub-base and bituminous roadbase control materials. The steps required to produce a cost effective and successful design for haunch repair are detailed. They are based on a flow chart approach to assist the user design, plan and execute the various stages of haunch repair. (A)