S0 Preamble to the Specification
S0 Preamble to the Specification
This Specification is a Code of Practice outlining a national standard applicable to all Undertakers when carrying out reinstatement as a part of executing street works. Broadly, the Specification and its appendices prescribe materials that may be used, the expected standards of workmanship and performance standards to be complied with at both interim and permanent reinstatement stages for the duration of the Guarantee Period (defined in Section S1.2).
There is a strong focus in this Specification on sustainability by encouraging the first time completion of permanent reinstatements, material recycling and the reuse of materials to minimise the carbon footprint of the reinstatement operation.
The Specification 'S' Sections are logically ordered, reflecting what practitioners need to know before commencing works, what will be required in order to complete the works and the obligations upon Undertakers once the works are completed.
Sections S3, S4 and S5 follow the normal sequence of operations carried out by Undertakers when breaking up or opening up the street and laying new or maintaining apparatus, namely, excavation, placing surround material to apparatus and the backfilling of the openings above the surround to apparatus to the underside of the specified unbound and bound material layers, which comprise the designed structure of the reinstatement.
Sections S6 and S7 set out the detailed requirements and permissible reinstatement methods for the bound materials in carriageways. Limitations on the use of preferred and permissible materials (more fully detailed in Appendices A1 and A2) are described. Sections S8 and S9 similarly set out the requirements for reinstatements in footways and verges.
Section S10 sets out the fundamental requirements for compaction of all permissible reinstatement materials, including guidance as to the degree of compaction necessary to comply with the Code of Practice, thereby supporting the required end performance of the whole reinstatement.
Sections S11 and S12 respectively cover ancillary activities which might be encountered during street works and the prescribed remedial measures in the event that the reinstatement is defective and/or causes settlement beyond the limits of the reinstatement.
The Appendices are an integral part of this Code of Practice, setting out significant amounts of technical detail, including the design of different reinstatements using materials and thickness specified in the Appendices. This reflects the various categories of surfaces normally encountered in reinstatements, which includes carriageways, footways and verges.
Incorporation of this type of detail into the Specification 'S' Sections was considered likely to impede the general flow of those clauses. Whilst the Appendices stand alone as sections of the Code of Practice, they in essence complement the Specification 'S' Sections.
Where considered beneficial, Notes for Guidance sections complementary to the Specification 'S' Sections and some of the Appendices have been included in the Code of Practice. However, Notes for Guidance are by definition notes or details which are thought to be useful to support practitioners to both understand and use the Specification and Appendices. They sit outside the Code of Practice and are not enforceable under law.
Specific to the reinstatement-related aspects within the Code of Practice, readers and practitioners will find reference to reinstatement materials in numerous parts of the Specification 'S' Sections and Appendices. These include:
- the overall class of materials, such as Hot Rolled Asphalts, Stone Mastic Asphalts, Asphalt Concretes and traditional Concretes used in some roads;
- different types of mixture within each class of material, such as Hot Rolled Surface Course and Hot Rolled Binder Course - these tend to relate to the relative position of the mixture within the overall reinstatement (generally the layer) and reflect the design function of the layer;
- different preferred (and permissible) mixtures for different layers;
- different thicknesses of mixture layers;
- specific requirements and limitations for surface courses.
Each of the above references has been intentionally assigned to different parts of the Code of Practice and it is essential that these are all taken into account when selecting the correct reinstatement design in a specific category of surface.
The reinstatement of flexible roads (and footways) is particularly more complex at the reinstatement design selection stage. To assist practitioners, Figure S0.1 sets out the intended materials selection process for flexible (and composite) carriageways.