Concrete is a hardened construction material that forms from a mixture of cement, water, and aggregates such as crushed rocks, sand, slag, and gravel. 

Concrete is the second most consumed material in the world after water. Yet, its negative impact on the environment can not be overestimated: cement production now contributes about 8% of the world’s greenhouse gas emissions. The majority of the carbon emission comes from the burning of fossil fuels to generate heat and start the cement-making process. Mining to extract raw materials such as sand and gravel for concrete leads to land degradation and water pollution. The concrete industry is also responsible for around 9% of the industrial water withdrawal worldwide.

The good news is that there are several sustainable alternatives to concrete, for example – green concrete, mycelium, hempcrete, bamboo concrete, ferrock.  

Green concrete  

Greencrete is an umbrella term for several eco-friendly materials which mimic the structural properties of concrete. 

Usually, different waste materials from industrial productions, mining and incinerator residue are used to create it. In general, it requires less energy for production and emits less carbon dioxide than usual concrete.

At the same time, It is more durable and requires less maintenance.

Hempcrete

Hemp concrete or hempcrete is a mixture of hemp shives – a waste product generated when processing hemp into fiber – lime, water and additives like sand. Hempcrete uses much less water than typical concrete and is much lighter. It also has superior thermal properties.

Hemp can be grown in a range of soils and climates, making it an easy-to-harvest crop all across the globe. Like ferrock, it can be regarded as carbon-negative because hemp stores a large amount of atmospheric carbon as it is grown.

It is a biodegradable material.

Ferrock

Ferrock is a carbon-negative concrete alternative. The material's name comes from ferrous rock, but it is primarily composed of waste steel dust and ground silica glass, with 95% of its components being recycled.

It is around five times more strong than typical cement. It is also flexible and can bend without breaking due to compression or seismic action. This property of ferrock makes it easier for artists to mold and experiment with unique forms and shapes for their sculptures.

Ferrock sets faster than concrete. What is more, unless the typical concrete it becomes even stronger when exposed to saltwater. That is why ferrock can be used for creating marine-based structures. 

It is renewable, recyclable, and non-toxic. 

It is yet a new material, that is why it is not widely available, and can be costly compared to convenntional concrete.

Bamboo concrete

Bamboo concrete is popular because it has excellent tensile strength. It is lighter than traditional concrete and has terrific flexibility because of its internal fibers. It is durable and resistant to corrosion.

The mycelium bricks are also much lighter and durable comparing to regular concrete. This material is resistant to fire, water and mold.