Exercise 2.3: Innovative Materials

Select one new material, that you consider being innovative, i.e. new, inventive, ingenious or that is at the cutting edge of new technologies, sustainability and material processes. After a little research I found cigarette butt bricks, researchers at Australia’s RMIT University have found that fired-clay bricks made with cigarette butts can save energy and help solve a global littering problem. (Matroos, 2016)

The disposal and littering of cigarette butts (CBs) is a serious environmental problem. Trillions of cigarettes are produced every year worldwide, resulting in millions of tonnes of toxic waste being dumped into the environment in the form of cigarette butts. As CBs have poor biodegradability, it can take many years for them to break down. (Mohajerani et al, 2016). The research found that using butts in the production of clay-fired bricks trapped the pollutants inside, preventing things like arsenic, cadmium, chromium and nickel from leaching into the environment. Countering 6 trillion cigarettes annually sounds like a losing battle, but the team believes it is achievable. Interestingly, it’s not just a case of stashing the butts somewhere out of sight: bricks made with cigarette butts can actually have superior properties than those without. According to the team, the energy used to fire bricks is reduced by more than half when butts are added, and the final product makes for better insulation. It’s a potential win-win: butt-bricks could help the environment by reducing toxic waste, making brick-firing more energy efficient and saving power in home heating. (Irving, 2016)

The following properties are valid for bricks with 10% cigarette butt content:

1. Density of cigarette butt Bricks is less than that of conventional bricks without cigarette butts.
2. Compressive strength of cigarette butt bricks is less than the conventional bricks by more than 85%.
3. Water absorption increases almost linearly with the increase of cigarette butt content.
4. Cigarette butt bricks have low porosity and shrinkage.
5. Bricks are light and have good insulation capability.
6. The percentage of cigarette butt addition is specified based on the type of project or works in which cigarette butt bricks are used. This is because different amount of cigarette butt in bricks modify brick properties.
7. Tests have been conducted on different replacement percentages like 1.5, 2.5, 7.5, and 10 percent. Each replacement quantity results in different physical properties. As the quantity of cigarette butts is increased, its detrimental effects on the bricks would be more obvious.

The advantages include

1. It gets that waste out of the environment.
2. It makes bricks cheaper.
3. Less energy-intensive bricks can be produced.
4. The energy needed to fire bricks can be cut by up to 58%.
5. Lighter and better insulator bricks are produced; meaning they could help cut household cooling and heating demands.
6. When the cigarette butts are fired in the bricks, the heavy metals and other pollutants are trapped and immobilised in the solid block so they cannot leach. 
7. Bricks shrinkage, porosity, and thermal properties are improved.
8.  Cigarette butts can be placed in bricks without any fear of leaching or contamination.
9. Cigarette butt bricks are an alternative to conventional bricks. (Hamakareem, s.d)

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The process is fairly simple. First, cigarette butts are collected through recycling programs. They’re disinfected at 105 degrees Celsius (or 221 degrees Fahrenheit) for a day, then stored in plastic bags. These butts are mixed with a typical sand-clay blend, then fired into bricks at 1,050 Celsius, or about 1,922 Fahrenheit.

“The high temperature in the firing process changes the chemical characteristics of the materials; materials are combined, and harmful chemicals are immobilized through the fixation process,” Mohajerani explains via email. “The results from our comprehensive leachate study show that the concentration of heavy metals in the leachate were in trace amounts that did not exceed the regulatory limits specified by USEPA and EPAV.” (Wilson, 2016)

Referencing

Matroos (2016) Science direct https://www.sciencedirect.com/science/article/pii/S0956053X16300988 (accessed 23.5.19)

Michael Irving, (2016) New Atlas https://newatlas.com/bricks-cigarette-butts-reduce-litter-rmit/43498/ (accessed 23.5.19)

Hamakareem (date unknown) The Constructor https://theconstructor.org/building/cigarette-butt-bricks/29224/ (accessed 23.5.19)

Mark Wilson (2016) Fast Company https://www.fastcompany.com/3060345/one-plan-to-banish-cigarette-butts-bake-them-into-buildings (accessed 23.5.19)

Images

Fig.1 and Fig.2 Bricks, Cubes, and Beams produced from materials mixed with cigarette butts https://theconstructor.org/building/cigarette-butt-bricks/29224/ (accessed 23.5.19)