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Concrete contributes around 8% of carbon dioxide (CO2) per year and is the second most used substance after water. It is used even more than fossil fuel, considering we burn approximately 7 billion tons annually. Still, there are no plans to replace or stop using concrete. Yet, it is clearly harmful to the environment.
The answer is in those 5 reasons:
1- Concrete Is A Versatile, High Compressive Composite Material
It has never been a material that can do what concrete can. You can customise its strength for specific applications based on the elements that go into manufacturing concrete, which consists of aggregate and cement paste.
Cement is versatile because:
1- Cement is a powder that is easy to store and manufacture
2- We can produce different types of cement with varying characteristics of strength based on the client’s needs
3- Has quick setting times, which gives it initial strength within 7 days.
4- When combined with steel, it gives us reinforced concrete which is strong in both compression and tension
As for aggregates, they are basically crushed rocks that are available in nature and quite accessible to mine and transport.
2- Currently, There Is No Reliable Alternative To Concrete
Unfortunately, despite all the promises of another substance that can replace concrete and be eco-friendly, it still does not come close to how reliable concrete is.
Materials such as compressed plastics or Hempcrete are a few examples of alternatives to concrete.
However, the issue is that:
1- Those products do not bond well with steel
2- Those substances do not share the same strength characteristics as concrete
3- Very expensive to manufacture and transport
The only material that was extremely promising was hardwood. However, using wood means cutting down trees. Although it is used in building houses because those structures do not experience high loads, usually 38% of every house being built in the US contains concrete found in the foundation, external brick walls and walkways.
3- Concrete Is Cheap And Easy To Manufacture
We are so accustomed to using concrete in everything. The first records of using concrete in construction date back to 6500 BC.
Competitively concrete is the cheapest building material. Nothing in the market rivals concrete; even if it existed, it would be costly because manufacturing a new product is always costly since you need to establish a plant and spend capital on R&D.
Concrete contains cement paste (calcium, silicon, aluminium, iron and other ingredients) and aggregates found in nature. Yet, the incineration of those elements and the chemical reactions between them produce CO2.
We have used concrete in almost everything. When building skyscrapers, concrete is heavily relied on to give us the strength required for the building to stay standing but also quite cheap to manufacture and use.
4- Construction Is Ultra Slow Change Industry
If a material existed, that could rival concrete in price, strength, and ease of manufacture. It would take decades to fully replace concrete because the new product requires industry education and patience to convince this ultra-slow-changing industry to change.
This is also because of the danger of ditching concrete for other building materials. Construction is one of the most dangerous industries to be involved in. Fatalities are very common in this industry.
Dealing with a concrete alternative could cripple this industry for decades. There will be many issues in construction and injuries and failed structures that will erase centuries of innovation that could easily send humanity to the stone age.
Engineers are very comfortable designing structures built from concrete because there are codes, building standards and computer designing software based on concrete as the building material.
Any changes would require reinventing the wheel, which is extremely costly and dangerous.
This will require a reinvention of the whole industry that is 10 times more complicated than the Auto industry.
Simple regulation changes and banning concrete use will not solve this issue because we first must invent an eco-friendly product that rivals concrete.
For more, read: 10 Reasons Why Construction Take So Long To Complete?
5- Current Objective Is Only To Minimise Concrete Carbon Footprint
Unfortunately, despite all the promises of moving away from concrete you see in the media, little work is done to move away from concrete.
The industry is mature enough to realise that the only way to move forward is to reduce the carbon footprint of concrete instead of replacing it.
The objective is to minimise the concrete carbon footprint from construction works by reducing emissions from concrete incineration plants and changing the chemical composite of concrete to reduce CO2 emissions.
Despite concrete being described as the most destructive material on earth, it has benefited humanity for hundreds of years. Because of concrete, we could build taller buildings and safe megastructures that we could only dream of accomplishing.
