An innovative new type of concrete might be able to help prevent flooding. Topmix Permeable is a fast-draining concrete that is able to take in up to 1,000 liters of water per square meter every minute.
The concrete was created by British company Tarmac. The company recently unveiled a video that featured a truck dumping 4,000 liters of water onto the surface of a parking lot constructed from Topmix Permeable. The water disappeared immediately, as though poured into an invisible hole.
Many people believe that the product could be particularly useful for areas prone to flooding and hurricanes. This comes at a time where cities in South Carolina recently experienced torrential rains of 20 inches or more from Hurricane Joaquin, resulting in severe flooding.
The material that is traditionally used to pave roads consists of a mix of largely crushed and finely crushed stones held together with a binding ingredient. Topmix Permeable leaves out finely crushed stones. The resulting material is porous and able to absorb large amounts of water.
The absorbent concrete is installed on top of a base of crushed stone, which rests above the soil. Water travels through the top surface, collects in the base-layer and is slowly released into the soil below.
Tarmac’s commercial director Richard Stares says, “We believe that the capacity is several times more than enough to deal with the heaviest rainfall we’ve ever experienced.”
The price of Topmix Permeable is comparable to that of other alternative concretes. It can be used on roads, parking lots, pathways and driveways.
The best feature of the innovative concrete is its ability to take pressure off of aging water drainage systems. It can also redirect rainwater into natural aquifers in order to reduce the risk of water shortages. The concrete also acts as a filter, preventing contaminants such as motor oil from entering the ground or waterways.
There are some downsides to Topmix Permeable, however. It is not recommended for busy areas because heavy usage will eventually destroy the surface layer. Additionally, highly porous material used to make the concrete is in limited supply. Similar types of concretes also have these issues.
However, Stares insists that his product is more durable than that of other highly absorbent concretes. He gives credit to the binding materials in Topmix Permeable.
“We’ve been able to get this bond so strong. We’ve been able to make this product that has a very high void space,” he says.
The term “void space” refers to the amount of airspace in a paving product. Typical concrete has a void space of about 20%. The void space of Topmix Permeable is 35%.
However, solving flooding issues in the United States will have to wait, as the product is not yet available in the country.