Tugas Akhir Sarjana Kuat Lentur Papan Gypsum dengan Substitusi Serat Abaka Safinatun Najah 1504101010065 Program Studi Sarjana Teknik Sipil Jurusan Teknik Sipil-Fakultas Teknik Universitas Syiah Kuala Abstrak Gypsum sebagai bahan bangunan saat ini banyak digunakan untuk membuat papan gypsum. Papan gypsum meskipun tidak diaplikasikan sebagai elemen struktural namun jika terjadi kerusakan akan menimbulkan bahaya yang dapat mengancam keselamatan manusia dan menimbulkan kerugian ekonomi. Oleh karena itu, untuk meningkatkan kekuatan papan gypsum banyak digunakan serat sebagai penguatnya. Pada penelitian ini digunakan serat alami berupa serat abaka sebagai bahan penyusun dan penguat papan gypsum. Penelitian ini bertujuan untuk mengetahui kuat lentur maupun sifat fisik papan gypsum dengan substitusi serat abaka. Dalam penelitian ini, papan gypsum komersial merek Jayaboard digunakan sebagai pembanding. Persentase serat abaka yang digunakan dengan variasi 0,5%, 1,0%, 1,5% 2,0% dan 2,5% dari berat gypsum. Adapun rasio air terhadap gypsum adalah sebesar 0,6. Benda uji papan gypsum yang dibuat berukuran 50 x 40 x 1 cm3 yang dipotong dengan ukuran berbeda-beda sesuai dengan pengujian. Pengujian dilakukan terhadap sifat fisik dan mekanik papan gypsum. Masing-masing pengujian dibuat sebanyak 3 buah benda uji untuk setiap variasi, sehingga jumlah total benda uji adalah sebanyak 75 buah. Hasil yang diperoleh dari penelitian ini menunjukkan papan gypsum menggunakan serat abaka menghasilkan nilai kuat lentur yang lebih baik dibandingkan papan gypsum komersial yang berupa papan gypsum Jayaboard. Nilai kuat lentur optimum adalah 54,919 Kg/cm2 yang dihasilkan oleh papan dengan substitusi serat 1%, sedangkan nilai kuat lentur papan gypsum Jayaboard adalah 36,190 Kg/cm2. Densitas tertinggi 1,210 gram/cm3 dan terendah 1,161 gram/cm3, termasuk papan berkerapatan tinggi. Kadar air tertinggi 17,590% dan terendah 16,451%, tidak memenuhi standar karena lebih dari 13%. Penyerapan air tertinggi 30,002% dan terendah 24,524%, memenuhi standar di bawah 35%. Pengembangan tebal tertinggi 1,245% dan terendah 0,471%, memenuhi standar di bawah 10%. Adapun nilai densitas dari papan gypsum Jayaboard adalah 0,592 gram/cm3, kadar air 16,156%, penyerapan air 48, 327% dan pengembangan tebal 0,646%. Kata Kunci : Papan gypsum, kuat lentur, sifat fisik, serat abaka Final Project Undergraduate Flexural Strength of Gypsum Board with Abaca Fibers Substitution Safinatun Najah 1504101010065 Undergraduate Program of Civil Engineering Civil Engineering Department of Engineering Faculty Universitas Syiah Kuala Abstract Gypsum as a building material is currently widely used to make gypsum board. Although gypsum board is not applied as a structural element, but if there is damage it will cause hazards that can threaten human safety and cause economic losses. Therefore, to increase the strength of the gypsum board, many fibers are used as reinforcement. In this study, abaca fibers are used as gypsum board filler and reinforcement. This study aims to determine the flexural strength and physical properties of gypsum board with abaca fibers substitution. In this study, the Jayaboard commercial gypsum board was used as the standard of comparison. The percentage variation of abaca fibers used were 0,5%, 1,0%, 1,5% 2,0% and 2,5% by weight of gypsum. The ratio of water to gypsum was 0,6. Gypsum board specimens were made measuring 50 x 40 x 1 cm3 which was cut in various sizes according to the testing. Tests carried out on physical and mechanical properties of gypsum board. Each test consists of three specimens for each variation, so the total number of specimens was 75 pieces. The results obtained from this study indicate that gypsum board using abaca fibers produce better flexural strength values than jayaboard commercial gypsum board. The optimum values of flexural strength was 54,919 Kg/cm2 produced by gypsum board with 1% fibers substitution, while the value of the flexural strength of the Jayaboard gypsum board was 36,190 Kg / cm2. The highest density was 1,210 gram / cm3 and the lowest density was 1,161 gram / cm3, including high density board. The highest moisture content was 17,590% and the lowest moisture content was 16,451%, this value was not fulfilled the standard because it was more than 13%. The highest water absorption was 30,002% and the lowest water absorption was 24,524%, this value was fulfilled the standard below 35%. The highest thickness development was 1,245% and the lowest thickness development was 0,471%, was fulfilled the standard below 10%. The density values of the Jayaboard gypsum board was 0,592 gram/cm3, moisture content was 16,156%, water absorption was 48,327% and thickness development was 0,646%. Keywords : Gypsum board, flexural strength, physical properties, abaca fibers