Azhari2016-02-252016-02-252016-02-251907-0500wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/7959This research aims to study an ideal composition of styrofoam-mixed lightweight concrete. The lightweight concrete mixes consist of cement, water, bottom ash, and styrofoam. In order to examine the properties of mixes, unit volume, compressive strength, and modulus elasticity of mixes were investigated. Wasted styrofoam obtained from box packages was grated to form small particles and used as lightweight aggregates. The variation of styrofoam content inclusion were 20%, 30%, 40%, 50% and 60% of concrete volume, and bottom ash used was 20% of binder (cement & ash) weight (based on a previous research). The results shows that unit weight, compressive strength, and elasticity modulus tend to decrease as styrofoam contents increase. In contrast, the strain of concrete mixes increase. Maximum compressive strength of 8.39 MPa was achieved at 20% styrofoam composition and 1.55 ton/m3 of concrete unit weight. The minimum one of 3.13 MPa was obtained at 60% styrofoam composition and 0.92 t/m3 of concrete unit weight. The use of 40% styrofoam content gives 7.46 MPa of compressive strength and 1.28 t/m3 of concrete unit weight, which satisfies lightweight concrete spesification for lightweight structure.enStyrofoamlightweight concretecompressive strengthunit weightUR-Proceedings