All construction work on pavements should be carried out following completion of general site works. Topsoiling must be done to adjacent areas to prevent wash down of fine materials.
Sub Grade
- Excavate to sub grade appropriate levels shown on site drawings to provide a minimum fall of 1:1000 to fin drain.
- All soft areas should be removed and filled with suitable replacement material to provide a stable sub grade.
- The sub grade should be compacted with a vibrating plate.
Kerbs/Edgings
The paved areas must be firmly restrained.
Heavy duty
- Kerb haunching must extend to a minimum depth of 150mm below the base of the kerb.
- The kerb/edging must extend with sufficient height above the haunching to accommodate the full laying course depth and block height.
SC Membrane® Geosynthetic
- Must be watertight - a taped joint will be insufficient.
- Joints should be fully welded.
- Can be completed on site or pre-formed off site and delivered ready for installation.
For further information contact: WTB Geotextiles on 0845 6005505
Sub-base
Lower layer of sub-base (10-63mm)
- Placed in 2 separate layers
- Vibrate each layer to compact
- Final pass taken with no vibration
- Compaction should continue until 97% of the compacted bulk density achievable under laboratory conditions has been reached- measured with a nuclear density gauge.
- The specified 350mm depth of sub-base may be varied by the Engineer to suit site requirements.
SC Intergrid® Geogrid
- Incorporated at the interface between the two layers of sub-base where required.
- Laid on the sub-base and joints should be overlapped by 300mm.
- Upper sub-base layer should be laid on top of the SC Intergrid Geogrid and compacted as before.
- A second intergrid can be incorporated underneath or within the sub-base at the engineers discretion and laid in the same way as the first SC Intergrid Geogrid.
Inbitex® Geotextile
- Lay Inbitex Geotextile on top of the sub-base overlapping joints by 300mm.
- The Inbitex Geotextile should be brought up to the haunched kerb/edging and cut-off flush with the surface of the paving.
Laying Course
- Lay and screed to level approximately 50mm depth of 2-6mm single sized crushed stone to BS EN 13242: 2002.
- Final level of the 2-6mm stone must be accurate - stone will compact down much less than sand when the surface blocks are vibrated.
The particle shape of the 2-6mm stone will also affect the degree of compaction. It is recommended that a small trial area should be laid prior to construction to determine the accuracy of final levels.
Block laying
- Pre-set the block level by 6mm to allow for the effects of settlement when laid against fixed edgings.
- The blocks and slabs must be tightly butt jointed ensuring that a good fit is achieved.
- Single or double stretcher course of Aquaflow blocks must be used around the periphery of the paved areas.
- It is recommended that lateral restraints (such as forest edging)should be installed in areas where vehicles turn and/or brake.
- The lateral restraints should be properly constructed and haunched with concrete.
Cutting block
- Cut to a tight fit and none are to be smaller than 30% of the unit block size with three machined edges.
- Cut across the 100mm and not the 200mm dimension.
- Blocks should be cut vertically and not under-scord.
- All block cutting should be carried out with a disc cutter.
Surface Finish
- The blocks should be vibrated with a vibrating plate Type DVP75/22'' or similar.
- 2-4mm clean quartzite or gritstone should be applied to the surface and brushed in. The tapers and slots between the blocks should be fully filled.
- Blocks should again be vibrated and any debris brushed off.