A new permeable concrete surface developed by Tarmac can prevent or minimise flooding by absorbing up to 4,000 litres of water in the first 60 seconds, and an average of 600 litres per minute, per m2.
Much of the property damage in recent flash floods was caused by water running off pavements or overflowing from drainage systems.
To prevent all that water from accumulating on the surface of our roads and footpaths, Tarmac has developed Topmix Permeable, a new type of highly aborbant porous concrete.
The concrete works by having a permeable layer on the surface, made up of relatively large pebbles through which water can drain almost instantly. This is followed by an ‘attenuation layer’, which feeds the water into a drainage system that connects with the city’s groundwater reservoirs. The water is fed straight back into the system for irrigation, drinking water, swimming pools, and firefighting purposes.
Tarmac has succeed in developing a surface layer version of permeable that’s capable of withstanding the weight of heavy traffic.
Topmix Permeable can not be used in conjuction with existing concrete – cities can install it to absorb the runoff from regular concrete.