Fly ash is waste from incineration in the form of ash. The silica contained in this ash is processed into nanosilica which is useful for increasing the compressive strength of concrete. In this study, the nanosilica was obtained by extracting fly ash using the heating method. The tests carried out in this study are X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Scanning Electron Microsc…