New Roads and Street Works Act 1991 Specification for the Reinstatement of Openings in Roads Third Edition (Scotland) January 2015 Approved by the Scottish Ministers under Section 130 of the New Roads and Street Works Act 1991
Appendix A8 - Compaction Requirements
A8.1 Granular, Cohesive and Cement Bound Materials
All graded granular, granular, cohesive/granular, cohesive and cement bound materials laid above the surround to apparatus shall be compacted in accordance with Table A8.1.
| Compaction Plant and Weight Category | Cohesive Material (less than 20% granular content) |
Granular Material (20% or more granular content including cement bound material) |
||||
|---|---|---|---|---|---|---|
| Minimum Passes/Lift for compacted lift thickness up to |
Minimum Passes/Lift for compacted lift thickness up to |
|||||
| 100 mm | 150 mm | 200 mm | 100 mm | 150 mm | 200 mm | |
| Vibrotamper | ||||||
| 50 kg minimum | 4 | 8 # | NP | 4 | 8 | NP |
| Vibrating Roller | ||||||
| Single Drum | ||||||
| 600-1000 kg/m | NP | NP | NP | 12 | NP | NP |
| 1000-2000 kg/m | 8 | NP | NP | 6 | NP | NP |
| 2000-3500 kg/m | 3 | 6 | NP | 3 | 5 | 7 |
| Over 3500 kg/m | 3 | 4 | 6 # | 3 | 4 | 6 |
| Twin Drum | ||||||
| 600-1000 kg/m | NP | NP | NP | 6 | NP | NP |
| 1000-2000 kg/m | 4 | 8 | NP | 3 | 6 | NP |
| Over 2000 kg/m | 2 | 3 | 5 # | 2 | 3 | 4 |
| Vibrating Plate | ||||||
| 1400-1800 kg/m² | NP | NP | NP | 5 | NP | NP |
| Over 1800 kg/m² | 3 | 6 | NP | 3 | 5 | 7 |
| All Above Plant | For Maximum and Minimum compacted lift thickness See Appendix A2.6, Table A2.2 |
|||||
| Alternative Compaction Plant for Areas of Restricted Access (including small excavations and trenches less than 200 mm width) |
||||||
| Vibrotamper 25 kg minimum |
Minimum of 6 compaction passes Maximum of 100 mm compacted lift thickness | |||||
| Percussive Rammer 10 kg minimum |
||||||
Notes for Table A8.1:
1) NP = Not Permitted
2) # = Not permitted on wholly cohesive material i.e. clay and/or silt with no particles > 75 micron (µm)
3) Single drum vibrating rollers are vibrating rollers providing vibration on only one drum
4) Twin drum vibrating rollers are vibrating rollers providing vibration on two separate drums
A8.2 Chalk Materials
Not used in Scotland
All bituminous mixtures for permanent reinstatements permitted in Appendix A2 shall be compacted to the in-situ air void requirements of Section S10.2.3. Guidance on compaction procedures that may be capable of achieving the specified air voids values is given in NG A8
Compaction should be discontinued if the mixture shows any signs of distress, regardless of whether the minimum number of passes suggested in NG A8 have been applied
Compacted materials shall be capable of being wet flush cored as follows:
i) hot materials - upon reaching ambient temperature;
ii) PCSMs - at 6 months from the date of the permanent reinstatement.