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
NGA8 Compaction Requirements
NGA8.1 There are no Notes for Guidance
NGA8.2 There are no Notes for Guidance
NGA8.3 Bituminous Mixtures
Table NG A8.3 provides guidance for compaction procedures that may be capable of achieving the specified air voids values.
| Compaction Plant and Weight Category | Bituminous Mixtures | ||||
|---|---|---|---|---|---|
| Minimum Passes/Lift for compacted lift thickness up to | |||||
| 40 mm | 60 mm | 80 mm | 100 mm | ||
| Vibrotamper | |||||
| 50 kg minimum | 5 # | 7 # | NR | NR | |
| Vibrating Roller | |||||
| Single Drum | |||||
| 600-1000 kg/m | 10 | 12 | NR | NR | |
| 1000-2000 kg/m | 6 | 10 | NR | NR | |
| 2000-3500 kg/m | 5 | 7 | 8 | NR | |
| Over 3500 kg/m | 4 | 6 | 7 | NR | |
| Twin Drum | |||||
| 600-1000 kg/m | 5 | 7 | NR | NR | |
| 1000-2000 kg/m | 4 | 5 | 6 | 8 | |
| Over 2000 kg/m | 3 | 4 | 4 | 6 | |
| Vibrating Plate | |||||
| 1400-1800 kg/m² | 6 | NR | NR | NR | |
| Over 1800 kg/m² | 3 | 5 | 6 | 8 | |
| All Above Plant | For Maximum and Minimum compacted lift thickness See Appendix A2.6, Table A2.1 |
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| Alternative Compaction Plant for Areas of Restricted Access (including small excavations and trenches less than 200 mm width) |
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| Vibrotamper 25 kg minimum |
Minimum of 6 compaction passes Maximum of 75 mm compacted lift thickness |
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| Percussive Rammer 10 kg minimum |
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Notes for Table NG A8.3:
1) NR = Not Recommended
2) # = Vibrotamper not recommended on permanent surface course of trenches > 500 mm width
3) Twin drum vibrating rollers are preferred for compaction of bituminous mixtures
4) Single drum vibrating rollers are vibrating rollers providing vibration on only one drum
5) Twin drum vibrating rollers are vibrating rollers providing vibration on two separate drums