1 PENGARUH PENAMBAHAN SERAT ROVING SEBESAR 0%, 2,5%, 5%, 7,5%, DAN 10% TERHADAP KUAT TEKAN DAN KUAT TARIK BETON NON PASIR DENGAN PERBANDINGAN AGREGAT 1 : 5 DAN FAS 0,4 Muhamad Abdil Basith 1 , Hery Suroso 2 , Aris Widodo 3 Pendidikan Teknik Bangunan, Universitas Negeri Semarang ABSTRACT The addition of roving fiber as an added material is part of the innovation in increasing the compressive strength and tensile strength of non-fines concrete. This research is intended to know the percentage of increase of compressive strength and tensile strength of non-fines concrete by addition of roving fiber at the planned concentration. The benefit of this research is to know the effect of adding roving fiber in non-fines concrete. The study used mixed composition with the ratio of the volume of flats which consist of cement and aggregate of 1: 5, while the roving fiber with concentration of 0% for control variables, 2.5%, 5%, 7,5%, and 10% for variable bound. The fiber concentration is taken from the weight of the cement. The tested sample was cylindrical in size 150 mm in diameter and 300 mm in height. The number of samples per test variant of 3 pieces and the total amount of 30 samples. From the test results showed that the control variables for the compressive strength of 3.65 MPa obtained, the largest value of compressive strength occurs around the concentration of fiber as much as 5% with a percentage increase of 31.92% of control variables with a compressive strength value of 4.81 MPa, While the smallest compressive strength value occurs at the concentration of fiber as much as 10% with a decrease percentage of 26.65% of control variables with a compressive strength value of 2.67 MPa. The value of tensile strength for control variables is 0.42 MPa, the largest tensile strength value is about 5% concentration of fiber with the percentage increase of 93.22% from the control variable with the tensile strength value of 0.81 MPa. Keyword: non fines concrete, roving fiber, compressive strength, tensile strength ABSTRAK Penambahan serat roving sebagai bahan tambah merupakan bagian dari inovasi dalam meningkatkan kuat tekan dan kuat tarik belah pada beton non pasir. Penelitian ini dimaksudkan untuk mengetahui persentase kenaikan kuat tekan dan kuat tarik belah beton non pasir dengan penambahan serat roving pada konsentrasi yang direncanakan. Manfaat yang diperoleh dari penelitian ini adalah dapat diketahui pengaruh penambahan serat roving dalam beton non pasir. Penelitian menggunakan komposisi campuran dengan perbandingan volume bahan susun yang terdiri dari semen dan agregat sebesar 1:5, sedangkan serat roving dengan konsentrasi sebesar 0% untuk variabel kontrol, 2,5%, 5%, 7,5%, dan 10% untuk variabel terikat. Konsentrasi serat diambil dari berat semen. Sampel yang diuji berbentuk silinder dengan ukuran diameter 150 mm dan tinggi