This research presents a study of the compressive strength porosity chloride penetration resistance to carbonation and corrosion of self-compacting concrete containing fly ash ground rice husk-bark ash and ground bottom ash. Portland cement (CT) is partially replaced with pozzolans 0-40% by weight of the cementitious materials. Fly ash ground rice husk-bark ash and ground bottom ash have a high potential to be used as a good cementitious material. The results show that the compressive strength and low porosity of self-compacting concrete improves substantially with partial replacement of Portland cement with fly ash. Self-compacting concrete mix cement containing 20-40% of pozzolans can be used to make cementitious materials. The use of fly ash ground rice husk-bark ash and ground bottom ash produces concrete mix with good strength and resistance to chloride and corrosion.

The effect of grinding on the chemical and physical properties of rice husk ash was studied. Four rice husk ashes with different finenesses i.e. coarse original rice husk ash (RHA0) RHA1 RHA2 and RHA3 were used for the study. Ordinary Portland cement (OPC) was partially replaced with rice husk ash at 20% by weight of binder. The water to binder ratio (W/B) of the mortar was maintained at 110%±5% with flow table test. Specific gravity fineness chemical properties compressive strength and porosity test of mortars were determined. The differences in chemical composition of the rice husk ashes with different finenesses from the same batch are small. The use of RHA3 produces the mortars with good strength and low porosity. The strength of the mortar improves with partial replacement of RHA3 in comparison with normal coarse rice husk ash. The use of RHA3 results in a strong and dense mortar which is due to the better dispersion and filling effect as well as an increase in the pozzolanic reaction.

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 research studies the potential for using classified fly ash from Mae Moh power plant in Thailand as a pozzolanic material. Three different fly ash finenesses viz. coarse Original Fly Ash (OFA) Medium Fly Ash (MFA) and Fine Fly Ash (FFA) were used for the study. Ordinary Portland Cement (OPC) was partially replaced with fly ash at 20 and 40% by weight of binder. 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). Compressive strength carbonation depth and porosity test of mortars were determined. FFA has a high potential to be used as a good pozzolanic material. The use of FFA produces mortars with good strength and low porosity. The resistance to carbonation of mortar improves with partial replacement of FFA in comparison with the normal coarse fly ash. The use of FFA results in a strong and dense mortar which is due to better dispersion and filling effect as well as an increase in the pozzolanic reaction.