tw1 concrete retaining wall block

New retaining wall system promises to revolutionise construction methods in large civil projects

ReMaCon Products of Gauteng has negotiated the exclusive rights for local manufacture of concrete retaining blocks designed for construction of retaining walls to over 20 m in height.


“This is a coup for us because the retaining wall system, which is new to South Africa but is well proven abroad, opens the way for us to provide solutions for large civil projects more competitively and advantageously than the incremental panel systems used for these purposes at present,” commented Silvio Ferraris, the company’s Managing Member.

The maximum height attainable with retaining blocks produced locally at present is 7 m at a slope of 86 degrees.

“The new block, the TW1, can be built in one structure to over 20 m in height at a slope of 86 degrees, enabling us to provide for the construction of retaining walls for highways, railways and other public embankment structures for which standard retaining block walls are unsuitable,” Ferraris pointed out.

The system, developed by Tensar International of the UK, comprises the specially designed TW1 block combined with high density polyethelene (HDPE) grid mats – known as Tensar uniaxial geogrids – that are attached by a special connector into the blocks and extend horizontally to secure and reinforce the earth bank, thereby turning the whole structure into a monolithic solid mass.

The grid and connectors – obtainable from Kaytech, the local distributors for Tensar International – are strong, inert and resistant to alkaline, chemical or biological attack.

“The system, which complies with British Code of Practice BS8006 and the SA Bureau of Standards’ SANS 207, offers huge savings. The British Board of Agreement has certified the system and certificates are available on request,” Ferraris said.

“The system currently used locally on major civil projects is extremely expensive. Cranes have to be used to install it and metal strips have to be attached to the panels to secure the structure in the earth bank. In addition, a high quality and more expensive fill material has to be used,” he explained.

By contrast, the TW1 system is erected by hand. “It is more labour-intensive, but it is far more cost-effective than the current system. It also requires a lower quality fill material, which is more readily available and less expensive.”

ReMaCon Products recently commenced production of the TW1 concrete retaining blocks in concrete face form and is due to start producing them in rock split face form later this year.

As with ReMaCon Products’ established range of concrete retaining block products, no mortar is required for the construction of retaining walls built with TW1 blocks.

“It is a simple but versatile block, used mostly as a closed face system and capable of accommodating curves and angles including 90 degree corners  in the retaining walls in which it is used. It is also a solid block and will not crush due to accidental damage, as hollow block systems often do,” Ferraris concluded.