Properties Improvement of Fired Clay Bricks Incorporating with Cigarette Butts

Abstract

Although small in size, indiscriminate littering of cigarette butts (CBs) can cause serious environmental impact. Several trillion cigarettes produced worldwide annually lead to thousands of kilograms of toxic waste. CBs accumulate in the environment due to the poor biodegradability of the cellulose acetate filters and, in doing so, they have become the most common litter item on our planet. This paper presents some of the results from a continuing study on recycling CBs into fired clay bricks. Physico-mechanical properties of fired clay bricks manufactured with different percentages of CBs (2.5%, 5% and 10%) and also of control brick samples are reported and discussed. To improve the properties, three different mixing times were tested with 7.5% of CBs incorporated in clay bricks, specifically at 15 minutes, 10 minutes and 5 minutes respectively. The impacts of these changes on physical and mechanical characteristics were evaluated. With 15 minutes mixing time, the measurement increased up to 114% and 12% for strength and density respectively compared to 5 minutes mixing time. On the other hand, values for water absorption, initial rate of absorption and tensile strength decreased by 22%, 29% and 5% respectively. Microstructure analyses of CB bricks were also investigated using ESEM. Attempts were also made to improve the properties by incorporating 3% of steel fibre into CB brick samples. Nevertheless, the addition of the steel fibre did not significantly improve the properties or the appearance of the manufactured samples.