In this research palm oil fuel ash was utilized as a pozzolanic material in blended Portland cement mortar. The mortar was tested on the normal compressive strength and the negative effect of carbonation in indoor environment using the accelerated carbonation test of 5% CO2 in 50% relative humidity. Three palm oil fuel ash fractions of different fineness viz. coarse original palm oil fuel ash (CPOA) medium palm oil fuel ash (MPOA) and fine palm oil fuel ash (FPOA) were used for the study. Ordinary Portland cement (OPC) was partially replaced by these palm oil fuel ashes at the dosages of 20% and 40% by weight of binder. The results showed that the incorporation of the ashes affected the strength and the carbonation depths of mortars. The strengths of mortar slightly decreased with the increases in the dosage of the ash. The fineness of ash on the other hand improved the strength and the carbonation of the mortars. The mortars containing FPOA exhibited high strength and relatively low carbonation in comparison to those using coarser MPOA and CPOA. The use of FPOA resulted in a strong and dense mortar owing to the increased packing effect and pozzolanic reaction. It was therefore demonstrated that the FPOA could be used as a pozzolanic material to replace part of Portland cement for use in the indoor environment.

In this paper the effects of carbonation on pore structure of blended pozzolan cement pastes were investigated. Ordinary Portland cement _OPC_ was partially replaced with ground palm oil fuel ash _POA_ ground rice husk ash _RHA_ and classified fine fly ash _FA_. The strength total porosity specific surface area and pore size distribution were tested. In general incorporation of pozzolans increased the total porosity of blended cement pastes in comparison to that of OPC paste. Carbonation of pastes under 5% CO2 and 50% relative humidity _RH_ for 28 days resulted in filling of the pore voids and possible attack on calcium silicate hydrate _CSH_ depending on the type of pozzolan used. After carbonation total porosity decreased and specific surface areas of the blended pozzolan cement pastes reduced indicating the infilling of voids. Pore size distributions of POA and RHA pastes were different to those of FA pastes. Large pores of the POA and RHA pastes were increased indicating coarsening of pores owing to possible attack on CSH. It is possible that POA and RHA were highly reactive and hence their uses resulting in severe carbonation compared to use of FA.

This paper presented a study on the strength and chloride resistance of mortars made with ternary blends of ordinary Portland cement (OPC) ground palm oil fuel ash (POA) and classified fly ash (FA). The mortar mixtures were made with Portland cement type I containing 0-40wt% FA and POA. FA and POA with 1wt%-3wt% retained on a sieve No.325 were used. The compressive strength and rapid chloride penetration depth of mortars were determined. The results reveal that the use of ternary blended cements produces good strength mortars. The use of the blend of FA and POA also produces high strength mortars and excellent resistance to chloride penetration owing to the synergic effect of FA and POA. A mathematical analysis and two-parameter polynomial model were presented to predict the compressive strength. The mathematical model correlated well with the experimental results. The computer 3-D graphics of strength of the ternary blended mortars were also constructed and could be used to aid the understanding and the proportioning of the blended system.

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.