Construction World June 2015

ROADS AND BRIDGES

MOLE DAMAGE

Rescuing roads from

The network of underground tunnels formed by this rodent leads to severe difficulties in road settlement and collapse and increases road maintenance costs in the Western Cape. Upon inspection of various sites, engineers from the City of Cape Town Metropolitan Municipality (CoCT) have noticed the tell-tale signs of mole rat damage. These include uneven road surfaces, massive decompression spots resulting in pot-holes, cracks in the asphalt as well as the obvious mole-heaps. To ensure the durability of the approved upgrades for these roads, consultants had no hesitation in specifying Kaytech’s Mole Barrier as the most effective solution to the problem. Mole Barrier, which consists of 2 mm thick, abrasion-resistant, flexible HDPE sheeting, is specifically manufactured for Kaytech to prevent the lateral burrowing of the Cape Dune Mole Rat and similar rodents. Supplied in 1 m x 20 m rolls, Mole Barrier sheets are installed vertically with a 100 mm overlap. It is a robust product and is puncture and tear-resistant; its smooth surface offers no purchase for the crea- ture’s powerful curved claws and long incisor teeth. Over the last five years a number of road projects in the CoCT metropolitan area have been successfully armoured against the Mole rat using Mole Barrier. The layer works of the access road to Muizen- berg’s Coastal Park Landfill Site were severely damaged. Consulting Engineers, Jeffares & Green, specified Mole Barrier and by the project’s completion Requad Construction had installed 2 000 m of the sheeting into the new layerworks. Later that year 600 m of Mole Barrier (1 m x 1 m) were installed by Empower Roads when Imperial Road in Mitchell’s Plain was upgraded. As part of the Bus Rapid Transit (BRT) system, portions of Orumba Road and Racecourse Road in Milnerton were widened to accom- modate the new bus lanes. Since the Cape Dune Mole Rat can easily damage newly constructed layerworks, the presence of numerous mole-heaps in the area suggested to HHO’s design engineers that these new lanes were also at risk. As protection, 2 000 m of Mole Barrier were installed by contractor, Exeo Kholeka. In a very large project undertaken by Kaulani Civils, 5 900 linear metres of Mole Barrier were installed along the 7 km long Botfon- tein Road in Kraaifontein during its rehabilitation. The proximity of farms to the road suggests there are colonies of moles present along the road. The contractor was impressed with the ease of instal- lation of Mole Barrier and was able to complete between 700 m and 800 m per week. Also in the Kraaifontein area is the new Scottsdene Housing Devel- opment. After design engineers from Bigen in Johannesburg, had initially specified concrete barriers to prevent mole infestation of the new roads, Kaytech suggested using Mole Barrier, demonstrating its ease of installation and cost effectiveness. This resulted in West Coast Civils and Brink & Heath, in a joint venture, installing over 5 000 linear metres of Mole Barrier. A Kaytech representative will visit Scottsdene in the foreseeable future to check that no mole damage has occurred since installation. More recently, Road Smart Asphalting has installed 600 linear metres of Mole Barrier along Bonteheuwel’s Netreg Road, as well as Empower Asphalting which did 600 linear metres along the widened road network of the Soetwater Camp Site near Kommetjie. No installa- tion problems were experienced in either of these projects. Undoubtedly the definitive solution for this specific problem Kaytech’s unique Mole Barrier has been approved by the City of Cape Town’s Roads Department, to the extent that it is now found in their annual tender documents. Mole Barrier has saved the City of Cape Town from otherwise expensive and extensive road rehabilitation work.

Since its initial development, Kaytech’s innovative Mole Barrier product has helped to extend the life of many rehabilitated roads in the south western Cape which had been mole-damaged. Mole Barrier has also been specified for use on numerous newly constructed roads in the region and these have been successfully protected from mole infestation.

> The Cape Dune Mole Rat, endemic to South Africa and found only in the southern and south western regions of the country, is not actually a mole but a species of solitary burrowing rodent whose natural habitat is sandy shore- lines and riverbanks that are dominated by grasslands and sedges.

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The simple installation of mole barrier and the mole barrier in position.

CONSTRUCTION WORLD JUNE 2015