Copper Slag of Pyroxene Composition as a Partial Replacement of Natural Aggregate for Concrete Production

Abstract

Copper slag, a by-product of the pyrometallurgical process used for obtaining copper from copper ore in Bor, Serbia, contains mainly silicon, iron, calcium, and aluminium oxides. Due to such properties, it is disposed of in landfills. Despite the favourable technical properties copper slag aggregates possess, such as low-water absorption (WA24 0.6%), low resistance to fragmentation (LA 10%), and low resistance to wear (MDE 4%), its use in the construction industry is still limited. The results of testing the technical properties of copper slag aggregates (CSAs) as a potential replacement for natural river aggregate (RA) are presented in this paper. The experiments included tests on three concrete mixtures with partial replacement of coarse natural aggregate with copper slag. The replacement of RA particle sizes of 8/16 mm and 16/31.5 mm with CSA in the amount of 20% + 50% and 50% + 50% resulted in an increase in the compressive strength of 12.4% and 10.5%, respectively. The increase of CSA content led to a decrease in water penetration resistance and salt-frost resistance of concrete, whereas the resistance to chloride ion penetration did not change significantly.

Environmental assessment of copper slag aggregate concrete

“…Standard methods used for the mix design and testing of NAC concrete can also be used for the design and testing of CSAC mixtures. Mix proportions of concrete together with tested compressive strength at 28 days and flow table results are presented in Table 1 [9]. The control concrete mixture was designed to meet the requirements for the C25/30 strength class.…”

“…One solution to the problems of industrial waste disposal is the application of copper slag in construction. Due to favorable physical-mechanical and chemical characteristics of copper slag, such as low water absorption (water absorption of aggregate (WA24) 0.6%), high particle density (apparent particle density (ρrd) 3.33 Mg/m 3 ), good resistance to crushing (resistance to degradation (LA) 10%) and wear (resistance to wear (micro-Deval) in a wet state (MDE) 4%), its use is possible in the production of building materials [9]. Copper slag in building materials has the potential to increase mechanical properties while also lowering costs and easing disposal issues [10].…”