Durability of concrete mixtures containing Iranian electric arc furnace slag (EAFS) aggregates and lightweight expanded clay aggregates (LECA)

This article reports the results of an experimental investigation on novel concrete mixtures containing electric arc furnace slag aggregates (EAFS) and lightweight expanded clay aggregates (LECA), focusing on the durability properties. Six concrete mixtures consist of EAFS-natural-LECA (M-Group) and five mixtures of EAFS-LECA (NGroup) compared with 100% EAFS as reference. Workability and density of the mixtures were studied as fresh properties and compressive strength, as well as durability indexes including the electrical resistivity (RCPT and four-point Wenner test), salt-scaling under freeze and thaw cycles, abrasion resistance (abrasive groove length and wear depth), durability under wet and dry cycles, and durability factor under freeze/thaw cycles. Results showed that application of both LECA and natural aggregates, by maintaining the structural-level strength, leads to density adjustment while increasing the freeze/thaw durability factor, improving dimensional stability and controlling the level of cyclic wet/dry-stains. An average increase of durability factor of M-Group and N-Group comparing to the reference were observed up to about 124% and 63% respectively. The results indicated the positive effects of using natural aggregate and LECA on modifications of reference mixture. Measured abrasive groove length ranged between 20 and 23 mm and the depth of wear ranging from 0.1 to 0.3 mm confirming the improving effects of physical structure of EAFS aggregates. The studied mixtures, namely M6 and N5 with 0.744 kg/m2 and 1.204 kg/m2 exhibited the lowest salt-scaling mass-loss with 31% and 112% increase compared with the reference.