FOR the past 30 years Terraforce, the Cape Town based pre-cast concrete licensor, specialising in modular, hollow core concrete blocks, has maintained a strong foothold in the South African concrete retaining walls market, while the past two decades has seen steady expansion into the international playing field.

Today, despite the economic challenges, Terraforce has managed to establish thriving production in Canada, the U.S.A., Australia, Turkey, India, Europe, Peru and United Arab Emirates and negotiations are underway with potential new licensees in Europe and some Asian Countries.

Holger Rust, owner and founder of the company, bases his business philosophy on the principle of environmental aesthetics, the aesthetic appreciation of human-influenced and human-constructed as well as natural environments: “A healthy environment and the well-being of society within are closely linked. The latter depends to a large extent on the quality and value of their living environments. Large expanses of asphalt and concrete planned without consideration and environment-supporting features will eventually erode the very foundations of our survival.”

Rust explains that it is the remarkable versatile nature of the blocks that makes the Terraforce Retaining Wall System so popular: “The design of the block is a good example of a product that can support all requirements of sustainable site development. Concrete retaining walls constructed using this system, due to flush-fitting horizontal interlock over full width of the block, are easily formed into complex curved shapes or into walls in which the upper and lower profiles are continuously changing.”

“The system also allows you a choice between round face - plant supportive - or flush face - smooth or split version - to suit specific requirements, and they present a closed vertical surface structure that provides maximum amount of soil mass within the wall and prevents backfill ersion, while at the same time offering uninhibited permeability,” Rust says.

Overall it represents an energy efficient segmental retaining wall system that requires low hardware input for manufacture, low transport costs and low inventory requirements at sales outlets. Being hollow, yet strong enough, the blocks require less concrete to do the job when compared to solid block systems.

Rust adds that a technological approach was very important in helping his business grow. Rigorous laboratory tests were also conducted locally and abroad pertaining to interblock shear resistance, whole block compressive strength and geogrid pull-out resistance. In the pull-out tests, the primary failure was rupture of the geogrid outside the blocks and performance was found to be above average, based on experience with a large number of systems tested over many years.

Today, the product range includes a rock face and smooth face block in 11 sizes, as well as the 4x4 Multi Step block used for creating affordable seating, the Terrafix and Terracrete blocks for erosion control and hard lawn applications and the Terralite block for smaller landscaping and erosion control measures.

A new design manual has been recently released and can be downloaded of the web site in the downloads section.

Thirty years ago, after working as an Architectural draughtsman for some years, Rust felt a strong desire to test his ability to start his business and survive.

Initially he began importing wire mesh gabions from Spain, later becoming involved in the construction of gabion retaining walls and erosion control measures.

After gaining some knowledge of the market, Rust soon realised that a more cost-effective, practical and aesthetically pleasing method of earth retaining was needed in South Africa. Ironically it was at that stage that his main competitors forcefully pushed him out of the gabion market.

After the first Terraforce S blocks (then still weighing in at 50kg) where produced on a small home built ‘egg layer’ block machine in 1984, Rust has never looked back.

In 1986, when the first license agreements were signed, daily production reached 400 blocks and eventually combined Terraforce block sales, equalling over 6 000 sq m per month, were achieved in Cape Town alone.

In 1990s, Terraforce blocks were well established in South Africa, with nine licensees producing in all major centres.

At the same time the first international licensee came on board and today Terraforce blocks are produced on all continents, with the Consent LLC in the United Arabian Emirates being one of the most successful additions. Today, about 500 000 blocks a month are sold world wide.