Design guide and specification for structural maintenance of highway pavements by cold in-situ recycling

This report describes research carried out under the Linear Quarry Project. The aims were to promote the use of cold in-situ recycling by providing evidence of acceptable in service performance and to provide guidance on structural design and a draft specification. Pathfinder methods for the measurement of end-product performance are also included. The report addresses three specific areas of research: (1) measurement of the condition of medium to heavy trafficked roads recently recycled using cold in-situ techniques and the determination of their life expectancy compared with design traffic; (2) construction of a road trial on the A3088 in Somerset to investigate the performance of both cement bound and foamed bitumen bound cold in-situ recycled materials; (3) the production of a structural design method for cold in situ recycling, a specification and a method of performance assessment. The report is divided into two parts. Part 1 comprises the Design Guide, which is supported by appendices that describe the research methodology and worked examples. Part 2 contains the Specification and Notes for Guidance on the Specification; the specification clauses are presented separately for cement bound material and bitumen bound material, so that they may be included in standard contract documentation.