Introduction
Construction can never be completed without concrete. Whether a building, an educational institution or any other structure is involved, concrete will always be present because of its strength, durability and low cost. However, have you ever thought about the environmental impact that the production process involves?
Ordinary Portland Cement (OPC) forms the largest proportion of concrete. OPC manufacturing causes the release of a great amount of carbon dioxide (CO₂) in the atmosphere. About 7–8% of the CO₂ in the world emanates from cement manufacturing. Given that one of the greatest challenges being faced today is climate change, research and engineering are exploring more sustainable ways of handling the challenge.
Carbon-Negative Concrete, on the other hand, is one of the latest sustainable innovations of constructing structures. Unlike ordinary concrete, carbon-negative concrete reduces but absorbs carbon in its manufacturing process.
Why Do We Need Carbon-Negative Concrete?
Conventionally, concrete has been used for constructing infrastructures for a long time; nevertheless, the negative effect of concrete on the environment is also significant. In the manufacturing process of one ton of cement, a lot of CO₂ is released into the atmosphere, which is one of the reasons for global warming.
To minimize this harmful effect, scientists began using some of the industrial by-products to replace a part of cement in the concrete, including Fly Ash and Ground Granulated Blast Furnace Slag (GGBS). It was done to improve the quality of concrete as well as reduce the usage of cement. But with changes in industries and shortage of by-products, scientists started researching the use of agricultural waste.
Not being buried or burnt in the field, agricultural residues can become useful construction materials.
Turning Agricultural Waste into a Valuable Resource
Many agricultural waste products which were deemed valueless have now become useful in the manufacture of sustainable concrete.
Products such as Rice Husk Ash, Sugarcane Bagasse Ash, Coconut Shell Ash, Palm Oil Fuel Ash and Groundnut Shell Ash contain high amounts of silica content. Mixing some portion of these substances in place of cement enhances the process of hydration in the concrete, yet at the same time minimizing the need for cement.
This is a good deal for all parties concerned as the farmers can dispose of their waste products, the builders will cut down costs and also protect the environment.
What is Biochar?
Biochar is one of the most intriguing materials employed in carbon-negative concrete.
Biochar refers to carbon-filled material created by heating biological material under low oxygen conditions using a method called pyrolysis. Commonly used raw materials for making biochar include agricultural by-products like rice husks, coconut shells, bamboo, and wood by-products.
What is truly remarkable about biochar is that the carbon captured by the plants throughout their lives is locked up within the biochar. Once it is incorporated into the concrete mixture, the carbon stays inside the structure for many years and is unable to escape back into the air.
Essentially, biochar concrete turns buildings into carbon sinks.
How Does Carbon-Negative Concrete Store Carbon?
There are two major ways of how carbon-negative concrete absorbs carbon dioxide.
Firstly, there is the method of biochar storage, which implies that carbon absorbed by the plants will be securely stored within the concrete.
The second method of carbon capture is known as carbonation. When carbonation occurs, calcium hydroxide in the cement undergoes natural reaction with carbon dioxide in the air to produce calcium carbonate. The latter not only absorbs carbon dioxide but also makes concrete more dense and robust.
Another method applied to increase carbon capture and concrete strength is accelerated carbonation curing when carbon dioxide is introduced into the concrete in the process of early curing.
All of this allows carbon-negative concrete to absorb more CO₂ from the air than it emits in the production process.
Performance of Carbon-Negative Concrete
People often believe that sustainable building materials have less strength than traditional building materials; however, this is not always the case.
When the proper amounts of biochar and agricultural residue are added, carbon-negative concrete proves to be highly effective. Carbon-negative concrete has high compressive strength, low water permeability, and high resistance to chemical attack. Such properties increase the durability of concrete structures and reduce maintenance costs.
Thus, carbon-negative concrete is highly applicable in many industries, from residential constructions to commercial buildings, from roads to bridges, from pavements to drainage systems, and even in precast concrete products.
The Role of Artificial Intelligence
Making the right concrete mix demands thousands of experiments that could take a lot of time and money.
Here is where Artificial Intelligence (AI) comes into play. The AI algorithms are able to process huge volumes of experimental data and forecast critical parameters such as the strength of concrete, its durability, ease of mixing, cost efficiency, and ability to store carbon.
Without the need for manual examination of numerous mixes, the research becomes faster using artificial intelligence.
Challenges Ahead
Even though carbon-negative concrete can provide us with many benefits, we still have some problems to tackle.
The nature of the agricultural waste varies due to different climates, soil types, and farming techniques, which makes these substances less predictable than regular cement. We need to develop proper standards for handling these materials and conduct additional tests regarding their durability.
Nevertheless, thanks to the ongoing research and developments, these difficulties get easier to handle every year.
Final Thoughts
The future of the construction sector is not only about constructing buildings that will last longer; it is all about constructing responsibly.
Carbon-negative concrete is an excellent example of the combination of engineering and environmental sustainability. Using biochar with agricultural waste, we will be able to lower greenhouse gas emissions, reuse waste products, and capture carbon in our buildings.
Further research into the properties of the product along with the optimization using Artificial Intelligence will enable carbon-negative concrete to revolutionize the entire industry.
Authors Bios:
1. Mr.M.Sakthivel, AP/Civil
2. Ms.S.Varsha, Student III/Civil
3. Ms.S.Sharika, Student III/Civil
4. Ms.M.Sakthipriya, Student III/Civil
Comments
Post a Comment