Karakteristik Beton Ringan Ramah Lingkungan Berbahan Arang Hidro Serat Kenaf dan Arang Aktif Batang Kenaf

Abstract

Beton ringan banyak diapilikasikan diberbagai infrastuktur bangunan. Dalam aplikasinya beton sangat rentan terjadinya pecah ataupun retakan, akibatnya kekuatan material beton menurun, sehingga dapat diminimalisir menggunakan bahan alam dari serat tumbuhan yaitu tanaman kenaf. Penggunaan bahan lainnya berupa arang aktif dari tanaman berpotensi untuk menjerap polutan berbahaya di udara melalui skema arang aktif. Tujuan dari penelitian ini adalah menganalisa pengaruh suhu aktivasi terhadap sifat arang aktif dan daya jerap polutannya, menganalisa komposisi yang tepat dari komposit semen dengan penambahan arang hidro serat kenaf dengan penambahan arang aktif batang kenaf terhadap pemulihan retak secara mandiri dan kemampuan menjerap polutan beton ringan. Penelitian ini terdiri dari persiapan bahan baku, proses karbonisasi hidrotermal, pembuatan arang aktif dan pembuatan beton ringan, kemudian dikarakterisasi meliputi analisis proksimat, daya jerap polutan, sifat mekanis beton serta dilakukan analisis pemulihan retak pada beton. Suhu aktivasi berpengaruh nyata terhadap kadar abu, zat terbang, karbon terikat dan daya jerap benzena. Semua arang aktif memenuhi syarat mutu arang aktif teknis yang ditetapkan standar SNI 06-3730-1995 untuk parameter kadar air, kadar zat terbang, kadar karbon terikat namun hanya sebagian arang aktif memenuhi syarat untuk kadar abu. Arang aktif terbaik terdapat pada suhu 600 ○C. Variasi serat kenaf tidak berpengaruh nyata terhadap kerapatan, kuat tekan, MOE, MOR dan daya jerap polutan terhadap formaldehida dan kloroform, sedangkan variasi arang hidro serat kenaf berpengaruh nyata terhadap daya jerap benzena dan amonia. Pemulihan retak secara mandiri pada beton ringan melalui siklus basah-kering mengalami pemulihan 70,38-100%. Komposisi terbaik beton ringan terdapat pada penambahan arang hidro serat kenaf 1,5% dan arang aktif batang kenaf 3%.

Lightweight concrete is widely applied in various building infrastructures. In its application, concrete is very susceptible to breakage or cracks, as a result the strength of the concrete material decreases, so it can be minimized using natural materials from plant fibers, namely kenaf plants. The use of other materials in the form of activated charcoal from plants has the potential to absorb harmful pollutants in the air through the activated charcoal scheme. The purpose of this study was to analyze the effect of activation temperature on the properties of activated charcoal and its pollutant adsorption capacity, analyze the correct composition of cement composites with the addition of kenaf hydro-fiber charcoal with the addition of activated charcoal from kenaf stems on crack recovery independently and the ability to absorb pollutants in lightweight concrete. This research consisted of preparation of raw materials, hydrothermal carbonation process, manufacture of activated charcoal and manufacture of lightweight concrete, then characterized by proxymate analysis, pollutant adsorption capacity, mechanical properties of concrete and analysis of crack recovery in concrete. The activation temperature significantly affected the ash content, volatile matter, bound carbon and the adsorption capacity of benzene. All activated charcoal met the technical activated charcoal quality requirements set by the SNI 06-3730-1995 standard for parameters of moisture content, volatile matter content, bound carbon content, but only some activated charcoal met the requirements for ash content. The best activated charcoal is found at a temperature of 600 ○C. Variations in kenaf fiber did not significantly affect density, compressive strength, MOE, MOR and pollutant adsorption capacity for formaldehyde and chloroform, while variations in hydro charcoal kenaf fiber significantly affected the adsorption capacity of benzene and ammonia. Crack recovery in lightweight concrete through the wet-dry cycle experienced a recovery of 70,38-100%. The best composition of lightweight concrete is found in the addition of 1,5% kenaf fiber hydro charcoal and 3% kenaf rod activated charcoal.