Pemanfaatan Fly Ash sebagai Subtitusi Parsial Semen dan Titanium Dioksida (TiO2) sebagai Pelapis Permukaan Kanstin Beton untuk Menurunkan Kadar Nitrogen Dioksida (NO2) di Udara

Abstract

Air pollution originating from motor vehicle emissions is an increasingly serious environmental issue, especially in urban areas. One of the main pollutants produced is nitrogen dioxide (NO₂), which can have negative impacts on human health, such as respiratory problems, and can also harm the environment. This study aims to develop environmentally friendly construction materials based on concrete by utilizing fly ash as a partial substitute for cement and Titanium Dioxide (TiO₂) as a photocatalyst to reduce NO₂ levels in the air. Fly ash, a byproduct of coal combustion, possesses pozzolanic properties and can improve concrete performance while reducing cement usage, thus contributing to lower carbon emissions in the construction industry. Meanwhile, TiO₂ is used for its ability to oxidize gaseous pollutants through photocatalytic reactions under ultraviolet light. The research was conducted by producing concrete curb specimens using varying fly ash contents of 0%, 5%, 10%, 15%, and 20% by weight of cement. After 28 days of curing, compressive strength, water absorption, and NO₂ reduction effectiveness tests were carried out. TiO₂ was applied to the surface of the concrete curbs through a coating method. The test results showed that fly ash compositions of 10–15% yielded optimal results in terms of compressive strength and water absorption. Additionally, the TiO₂ coating proved effective in reducing NO₂ levels in the air through photocatalytic processes when exposed to ultraviolet light. From these results, it can be concluded that the combination of fly ash as a cement substitute and TiO₂ as a photocatalyst in concrete curbs has great potential in supporting efforts to reduce air pollution and promote sustainable development in the construction sector.