Nanosilica is silica with a nanoscale size ranging from 1 to 100 nm, which serves to enhance the compressive strength of concrete. Nanosilica can be synthesized from kaolin waste. The materials used in this study include kaolin and a high-energy milling machine as a milling tool. The research applied variations in milling duration for 2, 3, and 4 hours. Microstructural testing methods, includin…