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EXPOSED AGGREGATE PERMEABLE PAVERS USED IN CAPE-BASED BUSINESS PARK DEVELOPMENT
February 8,
2023 420 420 
Exposed aggregate permeable pavers manufactured by CMA member, CEL Paving Products, have been used for the driveways of Phase 2A of Sandown Square, a secure business park development in Parklands, Cape Town, which has been brought to the market by Milnerton Estates.
Phase 1 of the development was completed in 2018, and the commencement of Phase 2B, which will involve additional permeable paving driveways, will be demand-driven.
This is the first time that CEL’s interlocking exposed aggregate paver has been manufactured in a permeable paving (PP) format and it had to be specially configured to facilitate a permeable paving application. CEL also supplied its non-permeable exposed aggregate interlockers for paving the development’s parking bay sections which extend off the roadways.
The recently completed parking zone at Sandown Square, where permeable-paved driveways are sandwiched between non-permeable-paved parking bays.
In addition, the estate’s pavements, which flank the roadways and parking bays, were paved with CEL’s exposed aggregate and polished bond pavers. And added to the mix, Jura flagstone pavers, manufactured by another CMA member, Revelstone, were used for paving a walkway-come-patio which abuts the Phase 2A building.
The civil works and paving was designed by civil engineer, Ingrid de Jager, of BVi Consulting Engineers. MLH Architects and Planners, Lovemore & Company, Lanser Civils and Seymour Paving were other members of the professional team.
De Jager says the ratio of permeable to non-permeable paving on the estate is 50/50.
CEL’s newly launched exposed aggregate pavers grace one of the driveways at Sandown Square.
“Using rainfall models we calculated the run-off of the whole development which slopes towards the south and each parking bay section was designed to drain into the PP roadways. Construction of the underground services, roadworks and the building was carefully coordinated and we held off on the PP work until all the wet works on the building had been completed. This was done to prevent any clogging of the PP installations with sand and/or building dust, and, as an additional precaution, we placed layers of Bidim geotextile on completed PP sections to prevent the incursion of any clogging material.
“Once the scaffolding was removed from the building we commenced with the layer works of the non-permeable parking-bay sections. In-situ material tested to a G7 standard was used for the sub-strata. This was followed by: a 125mm layer of G5 aggregate; a 125mm layer of cement stabilised C4 material; 20mm of bedding sand; and the exposed aggregate pavers.
CEL’s polished bond pavers create attractive pedestrian squares between parking bays.
“Kerb blocks, 250mm deep were used as edging for the parking bay sub-base and as a barrier between the non-permeable and permeable paving sections. We specified G5 aggregate for the parking bay section to ensure that the kerbing had sufficient support in the event of a truck or other vehicle driving over it.”
In order to accommodate the greater quantities of sub-base materials required for layer works of the PP roadways an extra 150mm of sub-strata was excavated. Designed with 30% voids throughout, the layer works comprise: Kaytech A5 Bidim geotextile; 250mm x 53mm aggregate; 100mm x 19mm aggregate; A2 Bidim geotextile; 50mm x 6mm bedding stone; topped with CEL’s permeable exposed aggregate pavers. The bottom layer of A5 Bidim was extended up the side of the non-permeable sub-base sections to effectively separate the two sections and to prevent any water seepage from the permeable section.
Drainage from the PP driveway sections is effected by two perforated pipes which were installed at the bottom of each section. One drains into a catch pit and the other into a manhole and both drain into the municipal stormwater system. And two catch pits at the gable end of the building feed surface and roof water via an underground pipe into the nearest PP drainage pipe.
Revelstone’s Jura flagstone pavers bordered with CEL’s polished bond pavers form an attractive walkway-come-patio.
De Jager said that in addition to controlling the flow of stormwater into municipal drainage systems, Sandown Square’s PP system will also remove some of the pollutants from the water through sedimentation and microbial action.
Furthermore, she observed that all PP systems require regular maintenance and to that end BVi had provided Milnerton Estates with a maintenance plan to prevent clogging.
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C.E.L. Paving Products is a proud CMA producer member. Click the logo below to visit the C.E.L. Paving Products website.
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