Di era globalisasi, pertumbuhan sumber daya manusia yang semakin tinggi meningkatkan kebutuhan di bidang pembangunan dan hal ini menimbulkan kebutuhan akan material untuk pembangunan tersebut salah satunya adalah penggunaan beton. Penggunaan beton sangat diminati karena keunggulannya yaitu kuat akan gaya tekan, ketersediaan material dasar, dan tahan akan cuaca , namun beton juga memiliki kelemahan yaitu berat sendiri beton yang menambah beban berat pada gedung, dan lemah akan gaya tarik

Penelitian ini dilakukan penambahan serat sabut kelapa dengan tujuan untuk solusi kelemahan beton ringan terhadap tarik serta membuat beton ringan lebih padat dikarenakan pori-pori beton ringan terisi oleh serat sabut kelapa sehingga kuat tekan dan kuat tariknya  meningkat serta mengurangi resapan airnya. Penambahan serat ini memiliki variasi penambahan sebesar 0%, 0.1%, 0.3%, 0.5% dan 0.7% terhadap volume benda uji.

Hasil penelitian dari penambahan variasi tersebut diperoleh bahwa kuat tekan beton tertinggi pada variasi 0.3% sebesar 5.06 MPa dengan berat volume 0.99 gr/cm³ dan resapan air 24.31%, sedangkan variasi tanpa serat atau 0% diperoleh sebesar 4.19 MPa dengan berat volume 1.05 gr/cm³ dan resapan air 23.07% pada umur 28 hari. Kuat lentur tertinggi diperoleh pada variasi 0.3% sebesar 0.92 MPa dengan berat volume 0.828 gr/cm³ pada umur 28 hari.

Kata Kunci:         Beton Ringan, Serat Sabut Kelapa

In this globalization era, the growing of human resources leads the needs of development and its material, one of them is concrete. The use of concrete is very desirable because of its advantages, it has strong compressive force, availability of basic materials, and wheather resistance, but concrete also has disadvantages, its weight adds heavy loads to the building, and weak of pulling force.

                This research was carried out with the addition of coconut fiber with the aim of solution to the weakness of lightweight concrete to tensile strength and to make lightweight concrete denser because the pores of lightweight concrete were filled with coconut fiber so that the compressive strength and tensile strenght increased it can reduce water absorption. The variation of fiber addition were 0%, 0.1%, 0.3%, 0.5% and 0.7% with respect to the volume of test object.

The result of addition of the variation showed that the highest concrete compressive strenght in the variation of 0.3% by 5.06 MPa with a volume weight of 0.99 gr/cm³ and water absorption of 24.31%, while the variation without fiber or 0% was obtained at 4.19 MPa with volume weigth 1.05 gr/cm³ and 23.07% water absorption at the age oft 28 days. The highest flexural strength was obtained the highest at 0.3% variation of 0.92 MPa with a volume weight of 0.828 gr/cm³ at the age of 28 days.

Keywords              :  Lightweight concrete, Coconut Fiber.