Abstrak
Fly Ash is the residual material from coal combustion process at steam power plant. Fly Ash is categorized as pozzolanic material because Fly Ash contains high levels of silica and alumina compounds. High content of Silica (SiO2) in Fly Ash will reacting to Ca(OH)2 to produce C-S-H (Calcium Silicate Hydrate), which is the main compound to build concrete strength.
Concrete which use high volume of Fly Ash (>50%) is known as High Volume Fly Ash Concrete (HVFAC). Concrete should be has high flowability and compacting by it self to reach good density, or known as Self Compacting Concrete (SCC). This research was conducted by combining the type of SCC concrete and Fly Ash with content of 50% as a cement subtituttion. The research is called as High Volume Fly Ash Self Compacting Concrete (HVFA-SCC). The purpose of the research was to analyze the effect of fly ash on the concrete mixing and maximum compressive strength.
The methode applied in this research is by experimental, which the concrete mix design use 50% of Fly Ash content for cement subtitution. The specimen used is a cylinder form with a height 30cm and diameter 15 cm. For the testing of hard concrete is apllied by using Compressive Testing Machine at the age of 28 days.
The maximum results of compressive strength testing for each spesiment are, , HVFA.50.A = 44.1390 MPa; HVFA.50.B = 32.8200 MPa.

Keywords : fly ash, HVFA-SCC, compressive strength.