In this study waste ash was utilized as a pozzolanic material in blended Portland cement in order to reduce negative environmental effects and landfill volume required to dispose of waste ash. The influence of waste ash namely palm oil fuel ash rice husk ash and fly ash on compressive strength and sulfate resistance in mortar were studied and evaluated by some accelerated short–term techniques in sodium sulfate solutions. Ordinary Portland cement (OPC) was partially replaced with ground palm oil fuel ash (POA) ground rice husk ash (RHA) and classified fly ash (FA). Single pozzolan and a blend of equal weight portions of POA RHA and FA were also used. The resistance to sulfate attack of mortar improves substantially with partial replacement of OPC with POA RHA and FA. The use of a blend of equal weight portions of FA and POA or RHA produced mixes with good strength and resistance to sulfate attack. POA RHA and FA have a high potential to be used as a pozzolanic material.

This paper presents a study on the strength and corrosion resistance of mortars made with binary blends of ordinary Portland cement (OPC) and ground rice husk ash (RHA) or ground palm oil fuel ash (POA). The mortar mixtures were made with Portland cement Type I containing 0-40% RHA and POA. RHA and POA with 1-3% by weight retained on a sieve No.325 were used. The water to binder ratio was kept constant at 0.5 and the flow of mortar was maintained at 110±5% with the aid of superplasticizer (SP). Scanning electron microscopy (SEM) was used for analysis. The compressive strength chloride penetration and corrosion resistance of the mortar were determined. The results show that strength as well as the resistance of mortar to chloride and corrosion can be improved by blending with RHA and POA. Thus RHA and POA have a high potential to be used as a good pozzolanic material.

This paper presents a study on the strength and porosity of mortars made with binary blends of ordinary Portland cement type I (OPC) sand and ground rice husk ash (RHA) or ground palm oil fuel ash (POA). The mortar mixtures were made with Portland cement Type I containing 0-40% RHA and POA. The water to binder ratio was kept constant at 0.5 and the flow of mortar was maintained at 110 +/- 5% with the aid of superplasticizer (SP). X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used on materials. Compressive strength and porosity of the mortar were determined. The XRD pattern confirmed that POA and RHA were mainly amorphous silica. The use of RHA and POA produced waste ash with relatively high strength. The porosity of mortar containing RHA and POA decreased with the low replacement level of up to 20% of pozzolanic but increased with the 40% replacement level. RHA and POA have a high potential to be used as a good pozzolanic material in concrete work.