The built world is obsessed with concrete. If you look back a few centuries ago, paved roads were but a dream. In the forthcoming years though, everything changed. With the invention of concrete and cement, roads were easier to manually make.
Concrete and high carbon emission:
Concrete is a mixture of cement, gravel, sand, water and different aggregates. One of its key components: cement – has to be heated to very high temperatures to form a clinker. This clinker is the reason cement adheres to concrete and makes it a hard-enough compound for even vehicles to move at high speeds on.
As you would have guessed right now, cement can only be heated to very high temperatures with the help of burning a huge amount of fuel. It is said that out of all the carbon dioxide emission of the cement industry, a whopping 40% comes from just burning fuels. More than 80% of the remaining carbon dioxide emission is due to chemical processing.
Some of the other impacts of concrete on nature are: • Damaging the topsoil – concrete causes permanent damage to the topsoil – the fertile layer of the earth. • Soil erosion – by damaging the topsoil, and instead enforcing a hard surface, concrete can cause soil erosion. • Increase heat level – because concrete is thicker and usually blacker than normal soil, it can cause an unusual increase in the heat level of an area.
Because of the several issues that we mentioned earlier, and some other industrial issues, research was done to find concrete alternatives. Non-corrosive alternatives were founded as early as 1923, when continuous basalt fibre (CBF) was researched. However, these alternatives still did not fix the main issue of going green. In the recent years, even big corporates have started to turn towards greener solutions – even if they are not industries. Some of the concrete alternatives that are greener than concrete is listed below: • Bamboo • Green Concrete • Ash-Crete • Silica Fumes • Magnesium sulphate concrete • Klingstone Paths
Bamboo is one of the oldest available building materials to mankind. Although very popular in feudal Japan, and some part of Asia and the South Pacific, bamboo has little use elsewhere in the world. By bundling together bamboo, houses can be built with the least amount of industrial intervention required. Another way is to treat bamboo with boron to make it harder for bigger buildings.
Bamboo makes for very hard wood sticks and can survive even the toughest tests of time. The reason they are becoming ever so popular in Latin America is because Bamboo is readily available, cheap, and a renewable resource. Bamboo also absorbs a lot of heat, making houses cooler in areas where it is inherently hot. Buildings made from bamboo are also very light.
By using waste from other industries, green concrete can be made. For example, wastepaper makes for an excellent aggregate material in concrete manufacturing.
Glass that dumps also makes for a remarkable replacement for cement as it increases the durability of the concrete. Because most bio-degradable plastic lasts many years, it makes for an excellent aggregate material. Using composite and foam beads to make concrete cement that is fireproof, sound absorbing and vibration-resistant is also a popular technique nowadays.
The reason why green concrete is in this list is because it makes use of the waste from other industries, making for an efficient and greener world.
Fly ash is used as an SCM (supplementary cementitious material) to make cement concrete. Because it is a by-product of burning pulverized coal, burning of additional materials is not required, effectively reducing the carbon emission. Fly ash can mix with lime and water to become an alternative to cement – which requires a massive amount of heat to produce. When blended with concrete mixture with aggregates, Ash-Crete makes for an excellent concrete material that is both strong, and easy to pump. Some types of Ash-Crete are even resistant to chemical attacks. More than half of the concrete used in the United States contains fly ash.
Silica Fume, with other name micro-silica, is amorphous polymorph form of silicon dioxide. It is a by-product – just like ash fly – of production of silicon metal or ferrosilicon alloys.
Sicilia fume makes for an excellent reactive pozzolan, and if used in concrete – can considerably increase the strength and durability of concrete. Just like fly ash, since it is a by-product from another industry, more energy does not need to expend to make silica fumes. By utilizing this by-product, industries are able to reduce industrial waste, making for a much greener and cleaner earth.
Silica fume concrete reduces the ability of electrical currents to even migrate from one place to another – making it an excellent compound in industries where risk of high voltage is prevalent. Silica Fumes also make for an excellent compound for producing a ball-bearing effect, effectively increasing the durability and viscosity of cement.
Magnesium Sulphate Concrete
Although still in initial stages, a compound made of magnesium sulphate is in the making. Magnesium sulphate is considerably easier to make for the industry. Without having to expend a large amount of energy on heating the material. Magnesium sulphate also absorbs carbon dioxide – which potentially helps reverse the damage dealt to the atmosphere. Studies show that if used in the proper amount, magnesium sulphate can dramatically improve strength of concrete with minimal stretch.
Companies that are researching MSC claim that the material is able to absorb 50%. More carbon dioxide than what an average concrete material emits.
Klingstone paths is a brand that makes concrete. Because gravel is much lighter than concrete, and much more porous, it reduces the damage to the topsoil. By combining gravel with a Klingstone path binding agent. It is possible to introduce a concrete-like effect without damaging the topsoil. Many houses in the United States use Klingstone paths in their gardens.
There is a growing body of research in field of concrete alternatives for the modern world. Studies show that the global process emissions in 2016 were only about 4% of emission from fossil fuels. A non-renewable resource – which is 30% lower than reported by the Global Carbon Project. We hope to update this article with more low-carbon cement alternatives once there are updates.