Imperial smelting furnace (zinc) slag as a structural fill in reinforced soil structures

Imperial Smelting Furnace slag is an industrial waste generated during extraction of zinc. The present study experimentally evaluates the suitability of Imperial Smelting Furnace slag (ISFS) as a structural fill for mechanically stabilized walls and reinforced slopes. Experimentally determined gradation, physical and shear strength characteristics as well as electrochemical properties of ISFS used in the present study satisfied the standard specifications for a structural fill of different Guidelines/Codes of Practice. Pullout tests were conducted on a newly designed and fabricated large size pullout test apparatus to evaluate the bond coefficient (fb)/interface apparent coefficient of friction (μS/GSY) between the geogrids and ISFS. The influence of geogrid geometry, ultimate tensile strength and type of polymer (HDPE and PET) on the geogrid – ISFS interaction was also examined, and the results were compared with those of geogrids in Badarpur sand (reference material). The μS/GSY value of all geogrids in ISFS were slightly lower as compared to those of geogrids in Badarpur sand, which is due to weak structure of ISFS particles compared to Badarpur sand. The experimental pullout test results were analysed using Artificial Neural Network (ANN) to model and capture the influence of several geogrid parameters and structural fill properties on μS/GSY.