6 July 2009



ne of the largest environmentally based paving projects of its kind, Shoprite Checkers’ huge distribution centre at Brakfontein, Centurion, is to be surfaced with permeable paving that will ensure storage of storm-water during heavy rains. The Aquaflow paving is designed to maintain a “sustainable and environmentally sound performance”, according to Taco Voogt, commercial product manager of Technicrete, which manufactures the internationally acclaimed paving system under licence.



A total of 20 000m² of high-strength interlocking Aquaflow blocks will be laid to accommodate the flow of heavily laden horse-and-trailer and interlink vehicles which will use the distribution centre. These pavers will be of 35mpa strength.



Voogt believes the distribution centre, now in the bulk earthworks stage of construction, will be the biggest “environment paving showcase” of its kind in the southern hemisphere.


“Aquaflow was specified by the engineers (KLS Consulting) with the surrounding environment in mind,” says Voogt. “Permeable paving is ideal for the purpose.”


Below the paved surface, a system of dams within the stone sub-base layer attenuate the force of the storm-water flow, enabling water to penetrate gradually into the natural ground so that there is no overloading of the existing storm-water system.


Hannes Kotze of KLS explains that the Aquaflow paving and sub-base for the distribution centre reach a combined depth of 480mm, and storm-water runoff filters through special slots in the interlocking paving blocks. Storm-water is retained within the 350mm thick stone sub-base layer. The sub-base layer has a 30% void ratio with a storage capacity of 100 litres/m². From this retention layer, water infiltrates the sub-surface.


Voogt believes permeable paving in heavy industrial warehouse areas such as this, where there can be heavy and wasteful water run-off, should be a compulsory bye-law requirement. “Tremendous volumes of water can be saved in this way by storing storm-water in holding dams and harvesting it for future use,” he says.” The problem with hard surfaces is that there is little infiltration into the ground-water system, and untold amounts of water are lost this way. Permeable paving permits the natural and thus environmentally beneficial absorption of water.”


This system, Kotze adds, also eliminates the need for large retention ponds.