|
PILGWERILY REGENERATION SCHEME
This successful use of Paverlock Jointing sand as part of a traffic calming scheme developed and designed by Newport City Council. It consisted of 4 speed reduction tables laid with Tegula concrete block paving on Commercial Road at the junctions of Ruperra Street, Tredegar/Mount Joy Streets, Alma/Albert Streets and Dolphin Street.
The contractor utilised by the Newport City Council was Encon Construction Limited based in Cardiff and the Paverlock ‘Top Up’ Jointing Sand was supplied via Civils and Lintels of Aberfan.
Due to the constraints forced by the need of the Utility companies to regularly access services in the area. The design was modified to provide a semi-rigid structure as opposed to a strictly flexible construction with the concrete block paving bedded into a 5:1 laying course. The advantage of block paving is that it can be readily ‘unzipped’ for access before being reinstated back to the original levels. The paved area was still expected to behave as a traditional pavement. In the past the use of traditional kiln dried jointing sand had proved not to be resilient and washed out from the joints.
The most efficient method of densifying the Paverlock Jointing Sand is to use a vibrating plate compactor as detailed in BS 7533: Part 3. The concern was that the use of a vibrating plate compactor to fully compact the concrete block paving and Paverlock Jointing sand into the joints may damage the underlying and now hardened 5:1 laying course. Utilising the advantage that the Paverlock Jointing Sand can be used in wet conditions or when the blocks are damp, a fine spray or drizzle of water from a watering can or hose pipe was used to densify the sand into the joints, until there was no further drop of sand in the joints. Using this method, slightly more time is required when compared to using a ‘traditional’ plate vibrator but the densification or compaction into the joint (and hence performance) will be ultimately the same. Any surplus jointing sand can be removed from the paved area by brushing or gently swilling the surface.
Once the joints are full then the area can be trafficked. The Paverlock Jointing Sand will have the appearance
of jointing sand and when touched it will have a cohesive and slightly tacky feel to it whilst in service. This mobility or
movement is needed to maintain the flexibility of the pavement under vehicular trafficking. Some minor settlement of jointing
material is to be expected in the early life of the pavement before detritus from the environment fills the joints, as full
compaction is unlikely to be 100% achieved during installation, whatever method of compaction is used. There will be
no loss of performance during this bedding in process as there will be sufficient jointing material to provide frictional
interlock and structural integrity to the pavement. Paverlock’s internal testing has shown that the frictional interlock
of our product exceeds that of kiln dried sands, in all weather conditions.
The key aspect of this product is that it will be retained in the joints. Paverlock Jointing Sand will not ‘harden or cure’ as with cement or resin based products to produce a rigid and inflexible jointing material, that will eventually crack under vehicle trafficking. Nor does it need to be applied in dry conditions (and kept dry for a further period of hours after installation).
Under prolonged periods of dry weather the Paverlock Jointing Sand may bind together to form a crust which prevents loss of sand from the joints particularly from wind erosion. This crust can be readily broken down under finger pressure. This doesn’t interfere with the structural integrity of the pavement, as the friable treated sand retains a frictional interlock that exceeds that achieved by using kiln dries sand. When wet the material will revert back to its cohesive and slightly tacky feel. With the weather conditions experienced in the UK we would expect the jointing sand to be predominantly damp for significant parts of the year.
Paverlock Jointing Sand is designed for use in flexible pavements and will allow the individual units to move and transmit the load under vehicle trafficking, without impacting on the structural integrity of the pavement.
21 September 2012.
Further information:
Peter Morton, Managing Director
The
owners of Woodside Cottage decided to replace their ageing 20 year-old blacktop drive with more modern and attractive concrete
block paving. They asked local builder and hard-landscaping contractor, Frank Sedgwick, to take on the project. The driveway has a very steep slope of around 1 in 8 and Mr Sedgwick was concerned that if he used conventional kiln-dried sand it would be washed out of the joints by heavy rain. Mr Sedgwick approached Paverlock for advice and decided to use Paverlock CBP. After the blocks were laid Mr Sedgwick installed the Paverlock CBP using the same technique as for kiln-dried sand taking great care to ensure the joints were completely filled as he felt this was important because of the steep slope. Mr Sedgwick said that the drive had withstood a torrential downpour only 24 hours after completion without suffering any noticeable sand loss. He also said , whilst I acknowledge that Paverlock CBP is more expensive than kiln-dried
sand, I am confident that it will stay in the joints and that I will not have to come back and re-sand them. I will definitely
use it again. 21 September 2012. Further information: Peter Morton, Managing Director |
