5 Concrete Alternatives

One of the main critiques of concrete in modern construction is that the process of manufacturing the material is not environmentally friendly. Alternatives to concrete are emerging, which are comparable in terms of cost, strength and durability.

With cement having to be heated to over 1500 degrees Celcius, concrete's carbon footprint is already very high before it is even applied in a construction environment. Here are 5 alternatives to concrete:

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Alternatives to Traditional Concrete

Ferrock is a building material that was invented in Arizona from small particles of steel. Added to this is silica, from crushed glass. The iron content within this steel dust corrodes when exposed to the air and forms iron carbonate. The name Ferrock basically means ferrous rock, and carbon is a key element of glass.

The resulting material is 5 times as strong as Portland cement, and is mixed in a similar way to cement. Ferrock is able to flex and compress more than concrete before it reaches breaking point.

Bekstone is formed from reclaimed limestone aggregate which is added to cement and water. This sets to form a block and can be used as a sustainable alternative to natural stone and bricks. The company Bekstone won an award from the Carbon Trust for the material’s low carbon footprint.

As the name suggests, Grasscrete is a combination of grass and concrete. The material consists of a concrete matrix, forming 47% of the surface. The remaining 53% can be made up of grass where the lattice shape leaves holes.

It could be argued that Grasscrete isn’t a material, rather a method of using two materials together. The principle is that the grass creates a permeable aspect to the surface, to facilitate drainage. Whether the grass can be cut using a lawn mower is another question.

Rammed Earth is another building term that is fairly self-explanatory, where subsoil is compacted and compressed into frames and allowed to dry. The low manufacturing cost and carbon footprint is offset by the high labour cost, since it requires high levels of manpower.

This traditional form of construction is one of the most sustainable methods as it uses local, natural materials. Also the materials can often be broken down and reused.

Hempcrete is another concrete hybrid, also known as hemplime. It uses the core of the cannabis plant in combination with lime and water to produce a well-insulated material. Whilst the hemp grows, it absorbs carbon from the atmosphere, which makes it a much more carbon-neutral alternative to traditional cement-based concrete.