PENGUJIAN EKSPERIMEN FREKUENSI ALAMI PADA BALOK BETON KANTILEVER DENGAN VARIASI CAMPURAN ONGGOK 10%

Onggok is waste from the process of making tapioca flour, the tapioca flour manufacturing industry in Tulung Klaten can produce quite large onggok waste. One of the uses of this onggok waste is to filter it with a No.4 filter and make it a substitute for fine aggregate in the concrete mixture, which is expected to make the frequency value better. The method in this study is a study with a test object using a 10% heap mixture on L-shaped cantilever concrete with a length of 80cm, perpendicular length 100cm, width 10cm and height 10cm and specimens using 2 samples with differences in reinforced concrete and unreinforced concrete. The results of the natural frequency values in this study are cantilever beams with reinforcement having a value of 0.39; 1.22 and 2.05 while the cantilever beam without reinforcement has a value of 0.14; 0.68 and 1.70. The conclusion in this study is cantilevered concrete with greater reinforcement because the stiffness of the concrete is greater in the presence of reinforcement.