Culverts: an integral component for water, road and mining infrastructure projects

Culverts: an integral component for water, road and mining infrastructure projects

3 000 x 3 000 Rocla culverts in operation at the new Life style shopping centre in Wilgeheuwel

The main function of culverts is to manage the flow of water from one side to the other of an ‘obstruction’. This can be a road, railway track, trail or other structure constructed in either the natural or designed flow path of the water.

Factors to be considered before design and installation are the site specific application, environmental impact ensuring that erosion is minimised and structural damage avoided. Incorrectly placed or designed culverts can result in culverts failing, becoming dislodged and in extreme pollution cases being clogged with vegetation and sediment.

Rocla, one of South Africa’s leading precast concrete product manufacturers, is a supplier of a wide range of culverts for infrastructure and other water flow related projects. Their production experience and quality controls along with technical design expertise in project assessment and product design has been successfully utilised for custom designed culverts as well as many major infrastructure developments such as Polokwane Eastern Ring Road and the rehabilitation of the D528 in George’s Valley, Limpopo.

Culvert range

Along with custom designed culverts for once-off projects, Rocla offers two distinct ranges of culverts, differentiated by the type of loading requirements, both available with associated precast base slabs.

For heavy loading applications, such as to provide a waterway below railway tracks, Rocla’s SATS SAR Rectangular Portal Culverts can be used. These, or custom units are also utilised in any application with excessive fill requirements with the culvert tunnel at the base of the fill zone, allowing either conveyor or vehicle access.

The standard SAR culverts are supplied in lengths of 1,22 m and designed for up to 10 m of fill. Culverts required for loading heights greater than 10 m are handled individually and designed in-house at Rocla Head Office.

For traditional loading applications, creating waterways below roads, trails or even drainage channels, Rocla’s Standard Rectangular Portal Culverts are the preferred solution.

These standard culverts range in size from a span of 450 mm to 3 600 mm, and heights from 300 mm to 3 000 mm. The strength classes for these culverts are 75S, 100S, 150S, 175S and 200S.

If time constraints are a factor for any project, the precast culvert option, along with the precast base, as opposed to casting in-situ, will save on project duration and provide quality assurances on final product.

Wingwall units for culverts

Rocla’s precast Wingwall units can be used at both the inlet and outlet of any channelled system making use of circular or rectangular portal culverts for stormwater applications. The natural flow path of water upstream of a construction is often wider than the culvert or pipe structure. Transition sections are then required to receive and direct the flow of this upstream water through the culvert/pipe. The same is true of the downstream end of the culvert/pipe section. The precast concrete Wingwall unit is the most effective structure to use for the effective transfer of this water, eliminating erosion and creating a smoother flow of water.

Rocla manufactures a wide range of precast concrete products that are effective and cost efficient for all infrastructure and general construction projects requirements. The company has representation in Namibia and Botswana in addition to their South African presence.

Rocla is part of the ISG which also includes Technicrete