ABSTRAK
Tujuan dari penelitian ini adalah untuk mengetahui seberapa besar pengaruh penggunaan abu vulkanik dan serat aluminium terhadap kapasitas kuat desak dan modulus elastisitas beton yang dihasilkan dengan variasi campuran yang telah ditentukan.
Penelitian dilakukan dengan penelitian eksperimental laboratorium. Dalam penelitian ini menggunakan benda uji berupa silinder dengan ukuran diameter 150 mm dan tinggi 300 mm untuk uji kuat desak dan modulus elastisitas dengan masing-masing kadar penambahan abu vulkanik sebesar 0 % dan 20 % dan serat aluminium sebesar 0 %, 0,5 %, 1 % dan 1,5 %. Proses pengujian meliputi uji bahan, uji kuat desak, dan uji modulus elastisitas.
Hasil pengujian beton yaitu sebagai berikut dimana nilai kuat desak beton normal dengan bahan tambah serat almunium dan abu vulkanik pada penelitian ini mencapai nilai tertinggi pada kadar serat almunium 1% dan abu vulkanik 20% dengan dengan kuat desak sebesar 23,44 MPa atau bertambah sebesar 12,90 % dibanding kuat desak beton normal. Kemudian untuk pengujian modulus elastisitas mencapai nilai nilai tertinggi pada kadar serat aluminium 1% dan abu vulkanik 20% dengan modulus elastisitas sebesar 22869,26 MPa. Hal ini menunjukkan bahwa terjadi peningkatan sebesar 7,08 % terhadap beton normal.
Kata kunci : kuat desak, modulus elastisitas, beton normal,  abu vulkanik,  serat aluminium
ABSTRACT
Today the times and technological advances require no exceptionin the field of building materials. Lots of research has been done on the building material. The material research not only on the determination of the exact composition of the mixture of materials, but also look for other alternatives such as the addition of additives and the replacement of a component with other components. The chemical reaction between cement and water to produce compounds that accompanied the release of heat. These conditions contain a great risk to the shrinkage of concrete that results in concrete cracks, so the need for improvement of one of them by the addition of volcanic ash and aluminum fibers. The aim of this study was to determine how much influence the use of volcanic ash and aluminum fibers pressed against a strong capacity and modulus of elasticity of concrete produced with a variety of pre-determined mix.
Research carried out by the laboratory of experimental research. In this study using the test specimen in the form of a cylinder with a diameter of 150 mm and a height of 300 mm for the strength test and modulus of elasticity prodded with each additional levels of volcanic ash at 0% and 20% and aluminum fibers at 0%, 0.5%, 1% and 1.5%. The testing process includes testing of materials, urged strength test, and test the elasticity modulus.
Concrete testing results are as follows where the value of compressive strength normal concrete with added fiber materials aluminum and ash in this study reached the highest value on the fiber content of 1% aluminum and 20% of volcanic ash with the strong urge of 23,44 MPa or increases by 12,90 % stronger than normal concrete persisted. Then for testing the modulus of elasticity reaches the value of the highest value on the fiber content of 1% aluminum and 20% of volcanic ash with the modulus of elasticity of 22869,26 MPa. This suggests that an increase of 7,08 % against the normal concrete..
Keywords: compressive strength, modulus of elasticity, normal concrete, volcanic ash, aluminum fiber