Durability of Blended PFA and POFA Geopolymer Concrete: Fid-Bau Portal

Durability of Blended PFA and POFA Geopolymer Concrete

Azreen, M. / Hussin, M.W.

Ordinary Portland Cement (OPC) concrete is one of the most widely used construction materials globally, though its production in construction has negative environmental impact. About 0.9 ton of CO₂ is emitted for every one (1) ton of cement produced. In order to reduce the amount of CO₂ emission from cement industry, the utilization of supplementary cementitious materials such as pulverized fuel ash (PFA), blast-furnace slag and natural pozzolans is common and effective. Geopolymer is an inorganic binder material and can be produced by a geopolymeric reaction of alkali activating solution with silica and alumina rich source materials such as PFA and blast-furnace slag. In this study, the durability of concrete such as the resistance to sulfuric acid and sulfate solutions due to the effect of blended as of PFA and palm oil fuel ash (POFA), along with alkaline activators were investigated. Consequently, the optimum mix design of the blended ash geopolymer (BAG) concrete and OPC concrete specimens were prepared with water to cement ratio of 0.5 by mass as control. The micro structural analysis by X-ray diffraction (XRD) was done. BAG concrete showed better performance in 2% sulfuric acid and 5% sulfate solutions. From micro structural analysis, it was evident that BAG binder gel (N-A-SH) produced more durable material compared with C-S-H binder gel of OPC. The BAG concrete is strongly recommended to be used as an alternative to OPC concrete in addition to its environmental friendliness. Abundant PFA and POFA can be efficiently utilized to produce a high performance concrete.