Assessment of the industrial utilization of scoria materials in central Harrat Rahat, Saudi Arabia

Although basaltic volcanic scoria deposits are widespread in and around the scoria cones present in the Harrats, very few occurrences have been evaluated and still fewer have been exploited. The scoria from a quarry in central Harrat Rahat was investigated and assessed for its industrial utilization. Cubes were prepared from several concrete mixes using scoria as lightweight coarse and fine aggregates in different percentages. The compressive strength values of the cubes were found to be acceptable and satisfy the ASTM (1995) requirement for structural concrete. The scoria was also assessed for its utilization as a cement additive. Pozzolanic activity was tested according to the Italian standards and found to be acceptable. The strength activity index with Portland cement and the effectiveness of scoria admixture in controlling alkali-silica reactions were tested according to ASTM (1995) standards. Mortar cubes were specially prepared for these studies using different mixes and different storage procedures. The results satisfied the ASTM (1995) requirements as cement additive. The utilization of scoria as a heat-insulating material was tested and the results were found to satisfy the ASTM (1995) requirements. This fact suggests it could be utilized in the manufacture of the building blocks. It is recommended to evaluate the other scoria deposits, exploit the economically feasible ones and utilize them for different industrial applications. The manufacturing of heat-insulating concrete or building blocks using scoria is of prime importance as an energy saver. (C) 2000 Elsevier Science B.V. All rights reserved.