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This study aimed to investigate the feasibility and advantages of utilizing ternary blended binders consisting of Ordinary Portland Cement (OPC), Densified Silica Fume (DSF), and Ultrafine Palm Oil Fuel Ash (UPOFA) on the engineering and transport properties of Green High Strength Concrete (GHSC). A variable proportion of silica fume (5, 10, 15, and 20%) and up to 50% of UPOFA was incorporated as a partial replacement material from the total volume of cement binder into the GHSC. For fresh concrete, the results showed that the DSF inclusion increases water demand and reduces GHSC workability. Whereas for harden concrete, a considerable improvement in early strength and transport properties of GHSC with ternary binder inclusion. The highest relative strength was achieved at the early age of 1 day, which was up to 139.7% at 15%DSF content in (OPC-UPOFA-DSF15) GHSC. Meanwhile, the greatest improvement in the transport properties; water absorption, porosity, permeability and rapid chloride permeability of the GHSC was realized with 20% of DSF at 28 days in (OPC-UPOFA-DSF20) GHSC. Thus, in current study the results indicate that the combination of up to 65% (UPOFA and DSF) as a substitution binder with cement could produce GHSC with superior engineering and transport properties. [ABSTRACT FROM AUTHOR]

The performance of alkaline activated ground slag/ultrafine palm oil fuel ash (AAGU) mortars upon their exposure to 6% of H2SO4aq (acid) for 60 days was investigated. The mortars were prepared with NaOH4aq of varied concentrations and Na2SiO3aq (Ms-SiO2/Na2O = 3.3) activators and then cured at a temperature of 60°C for 24 h. The findings through strength, microstructural examination, and product characterization revealed that sulfuric acid attack could cause the disintegration of microstructure through the removal of the key elements-Ca, Mg, Na and Al-which resulted in the formation of gypsum, expansive shrinkage cracks, and a reduction in strength retention. Maintaining the slag content, concentration of NaOHaq, Na2SO3aq/NaOHaq ratio, and the mixing water content in the range of 20-40 wt.%, 8-10 M, 1.0-2.5, 5-10 wt.% of the pozzolanic materials (PMs), respectively could enhance the resistance of AAGU mortar subjected to sulfuric acid attack. [ABSTRACT FROM AUTHOR]