ABSTRACT Concrete that uses POFA (Palm Oil Fuel Ash) as a replacement of cement and a silica combination is known as POFA-blended concrete with silica as reactivity improvement material for POFA. This study aims to examine compressive strength, porosity, shrinkage, weight change, and the effect on environment using Toxicity Characteristic Leaching Procedure (TCLP) in peat water curing for 0, 7…