Abstract

This paper reports the results of an investigation on the potential industrial utilization of volcanic scoria. The scoria is assessed for its utilization as a cement additive.  Pozzolanic activity of ground scoria is tested according to the Italian standards and found to be acceptable. X-Ray Diffraction (XRD) analysis and Differential Scanning Calorimetry (DSC) are conducted on finely ground scoria based blended cement paste and mortar for the characterization of hydration products. The strength activity index with Portland cement and the effectiveness of scoria admixture in controlling alkali-silica reactions and autoclave expansion are tested according to ASTM standards using different mixes. The results satisfy the ASTM requirements and confirm the viability of using ground scoria as a cement additive. The suitability of using scoria as both fine and coarse aggregate in lightweight concrete production is assessed and compared with other lightweight aggregates. The properties of scoria concrete (SC) are evaluated by conducting comprehensive series of tests on workability, air content, density, strength, drying shrinkage, and water permeability. Developed SC mixtures have attained required strength and density to be accepted as structural lightweight concrete. The utilization of scoria as a heat-insulating material is also tested and the results are also found to satisfy the ASTM requirements. Scoria concrete shows good heat-insulating characteristics and can be used in building construction as an energy saver. 

Key Words: Scoria, Lightweight concrete; Pozzolanic activity; Alkali-silica reaction, Autoclave expansion, Drying shrinkage; Permeability; X-Ray Diffraction; Differential Scanning Calorimetry.