Analisis Hasil Pengujian Kuat Tekan dan UPV pada Sampel Silinder dan Kubus Beton Padat Gilas dengan Pemanfaatan 25%, 50%, dan 75% Terak Nikel Halus sebagai Substitusi Agregat Halus = Analysis of Compressive Strength Test Results and UPV for Roller Compacted Concrete (RCC) Cylinder and Cube Samples with 25%, 50%, and 75% Utilization of Fine Nickel Slag as a Substitute for Fine Aggregate