Evaluation of Powdered Scoria Rocks from Various Volcanic Lava Fields as Cementitious Material

Abstract

In this study, the large deposits of volcanic scoria rocks (SRs) of the Arabian Peninsula were investigated as cement replacement materials. The powdered SRs procured from three separate regions (SR1, SR2, and SR3) were incorporated in concrete mixtures at three replacement levels (10%, 20% ,and 30%, by cement weight). Additionally, two reference concrete mixtures with silica fume (SF) and ground quartz sand (GS) were fabricated for benchmarking. Fresh properties, compressive strength, chloride-ion penetration resistance, and pore-size distribution from mercury intrusion porosimetry (MIP) were obtained. Microstructural and elemental spot analyses using field emission scanning electron microscopy (FESEM) analyses of samples from concrete mixtures were performed. The results showed that powdered SR samples exhibit clear variations in morphology and mineralogical compositions depending on the volcanic lava field. The strength activity index (SAI) of SR3 was higher than SR1 and SR2 indicating higher pozzolanic reactivity. The compressive strength of concrete mixtures incorporating SRs is affected by both SR source and its replacement level. SR mixtures yielded improved chloride-ion penetration resistance compared with GS and control mixtures but much lower than SF. The microstructural analyses revealed that SR3 particles have higher pozzolanic reactivity than SR1 and SR2.