Compressive strength, porosity, and sorptivity of blended Palm Oil Fuel Ash (POFA) concrete containing silica fume in peat water

Abstract

Blended Palm Oil Fuel Ash (POFA) concrete has the potential for application in organic acid environments such as peat land. However, there is a need to improve resistance of blended POFA concrete using silica fume as a pozzolanic material. There are limited studies of the blended POFA admixed with silica for organic acid exposure. In this study, compressive strength, porosity, and sorptivity of blended POFA concrete admixed with silica such as silica fume has been investigated by exposing the samples in peat water. Portland Composite Cement (PCC) concrete with similar target strength was used as a control mix. The blended POFA concrete contained 0%, 20% and 40% POFA as a cement substitute. Micro silica or silica fume was added with concentrations of 10% in each mixture. Portland Composite Cement (PCC) with similar target strength was used as a control mix. The resistance of the POFA concrete specimens to organic acid attack were measured by compressive strength, porosity and sorptivity development at 7, 28 and 91 days. Compressive strength of control mix declined, while strength of PCC and PCC-POFA concrete containing silica fume increased at 91 days. Porosity and sorptivity of PCC and blended OFA concrete followed the same trend with the compressive strength. Thus, blended POFA concrete containing silica fume has better resistance in peat water than that of the control mix.