COMMON QUESTIONS AND ANSWERS
How much steel do you extract & what happens to it?
At the primary crushing stage, we remove about 100 tons per month. During the secondary and tertiary crushing processes, we then remove a further 10 tons per month, comprising mostly screws, nails and wire. All of the steel that is removed is recycled.
Can you recycle clay bricks?
Good quality well fired clay bricks make a good aggregate, but most of the clay bricks that come through the system (ROK’s) are not of a high quality and do not make good concrete aggregates. We therefore are very strict about the material we accept from the demolition site and try to only accept concrete and stone.
What happens to all the paper, plastic and wood that you extract?
This material is lighter than the rest so can be extracted using a stream of pressurized air to blow them out. All of this material is then removed to a waste facility. We are currently investigating alternative uses for the wood.
How much recycled material do you use?
On average we use 70% recycled material in all our bricks,blocks,Retaining wall blocks and decking blocks AND have now introduced 15% recycled material into our wet-cast paving products. We use roughly 70,000 tons of recycled materials per year in manufacturing our products although we produce significantly more. This is equivalent to 4800 truck loads (of 10 cubic meters each) of material. The excess not used by ourselves is sold as a filling material to the civil construction sector.
Is it more expensive to use recycled materials or “Green” bricks?
No, the cost of producing the recycled aggregates is more or less on par with buying virgin aggregates through the quarries as the recycling equipment is expensive and the material is hard wearing on the equipment. So the finished product is completely market related. It is fairly unique to find a product with such good environmental benefits that does not cost more than the conventional product.
Are the aggregates that you produce as good as virgin quarried aggregates?
They are in fact better. This is because our process produces a stone and sand aggregate that is symmetrically cubical in shape and screened. This is vital in terms of shear strength. It also aids the movement of the cement particles during the mixing process, thereby ensuring that the cement is properly circulated throughout the entire mix. Due to the higher cost of “round” stone and “screened” sands, most other brick manufacturers are not prepared to pay extra for them.
If I build a house using Cape Brick’s products, roughly how much energy or electricity would I be saving?
A typical residential house, using 40,000 bricks, would result in an energy saving of:
- 21,000Kwh when compared to conventional concrete bricks. This is equivalent to the energy required to power 23 ordinary size houses for 1 month!
- 82,000Kwh when compared with conventional clay bricks. This is equivalent to the energy required to power 91 ordinary size houses for 1 month!
Average (ordinary) household electricity consumption in SA (per Eskom published figures) is 900Kwh per month.
How does using recycled aggregates to make your bricks affect the product quality?
As already mentioned, it actually improves the final compressive strengths of our products, due to the improved qualities of the recycled aggregates when compared to quarried aggregates (unspecified dust as used by the bulk of manufacturers). We exceed all the quality standards as prescribed by the SABS and are recognized by the Concrete Manufacturers Association (CMA) as being one of the leading manufacturer members in terms of quality masonry.
There are so many brick suppliers out there claiming to be environmentally friendly, so how do I know that Cape Brick’s products are genuinely “green”?
This is big problem in South Africa. Everyone claims to be “green” but in reality very few really make a difference. Putting a recycling Logo on your product doesn’t make you green. You need to do things differently to make a difference. We have had our products tested and endorsed by EcoSpecifier SA and are currently the only brick manufacturer approved by them as being environmentally friendly. We have deliberately avoided joining associations that claim to represent “Green” producers, but who do not actually do a proper verification or embodied energy calculation.
“Ecospecifier SA aim is to help building professionals including architects, designers, builders and specifiers, as well as keen homeowners, to shortcut the eco and healthy materials sourcing process.
Its broader aim is to help create a more sustainable physical environment by increasing the use of environmentally preferable and healthy products, materials and design processes”