An industrial-waste binder met the strength requirement for mine backfill in a peer-reviewed laboratory and field study. Field strength reached 2.3 megapascals against a requirement of 1.8, but remained below the corresponding laboratory result. A separate calculation found a large emissions advantage per unit mass of binder compared with Portland cement.
Mine backfill fills excavated underground spaces and must combine adequate flow with strength. One peer-reviewed study tested a binder derived from industrial wastes in laboratory samples and a field application. The field material reached 2.3 megapascals of compressive strength against a design requirement of 1.8 megapascals. Its strength was nevertheless about 13% below the corresponding laboratory measurement.[1]
The binder combined steel slag, blast-furnace slag and alkaline slag, with performance varying across mixtures. More alkaline material reduced fluidity. Researchers examined hydration products, pore structure and drying shrinkage to understand differences in strength. A denser internal structure and shrinkage-compensating mineral formation were among the mechanisms considered. Successful results for selected mixtures therefore cannot describe every waste-based binder.[1]
The emissions calculation put the waste binder more than 95% below Portland cement per unit mass. Mixture proportions had a different significance when emissions were compared against material strength instead of mass. This accounting concerns binder production, with a different scope from the emissions of an entire mine. Waste composition, long-term material behavior and local application conditions remain relevant to using the result elsewhere.[1]
