Design of permeable asphalt mix (PAM) with cigarette butts (cellulose acetate) as additives

Abstract

Cigarette smoking is one of the most well-known tobacco products worldwide. A discarded cigarette butt is made primarily of cellulose acetate fibers, a type of microplastic that could be used in various construction materials such as asphalt. Using asphalt, most specifically permeable asphalt, is helpful in countries with high average rainfall because its key feature, along with the number of air voids, is its ability to let water pass through. This study proposes a design of a permeable asphalt mixture with optimum properties in terms of its stability, flow, and percent air voids. The collected cigarette butts underwent a thorough washing process wherein they were washed with five wt.% NaOH and one wt.% acid solution and dried. The extracted cellulose acetate with 0%, 2.5%, 5%, 7.5%, and 10% of the total weight of the mixture was added to the asphalt mix. A Marshal and flow test were conducted on each specimen, and the mixture with 2.5% exceeded the minimum requirements for stability, and every sample passed the required range for its flow. The bulkspecific gravity test shows that as cigarette butts increase, the bulk density decreases, which contradicts the increase in air void. Thus, considering the results of the tests, the researcher concluded that 2.5% of cigarette butts are the most desirable design for permeable asphalt mix.