Application of electric arc furnace slag for stabilisation of different tropical soils

ABSTRACT

Steelmaking wastes have been reused in civil construction to decrease environmental damages. This work evaluated the use of fines of oxidising electric arc furnace (EAF) steel slag (F_EAF) as stabilising agents of two different soils Tests for geotechnical characterisation of soils and chemical, physical, and morphological characterisation of F_EAF were carried out. Natural soils and soil-F_EAF mixtures were subjected to standard Proctor compaction, unconfined compression strength (UCS), California Bearing Ratio (CBR), and resilient modulus (RM) tests. F_EAF provided UCS increases up to 128%, maximum dry density increases up to 6% and optimal moisture content reductions up to 10%. The highest improvements were provided by 15% of F_EAF (UCS increases from 7 to 56 days of A-7-5(19) and A-2-7(0) soils were 60% and 21%, respectively). Regardless of the curing period, CBR index of A-7-5(19) soil with 15% F_EAF was 60–65% of CBR index of A-2-7(0) soil containing 15% F_EAF. Similar reductions (27–29%) in CBR swelling were observed in both soils. Incorporation of 15% F_EAF into A-7-5(19) and A-2-7(0) soils provided RM increases of 30% and 45%, respectively. Mechanical properties increases were attributed to filler effects and improvements in cementitious reactions F_EAF improved soils’ performance, enabling their use in pavement design and earthworks.

KEYWORDS:

• Pavement construction
• soil stabilisation
• steel slag
• recycling
• sustainability

Acknowledgments

The authors thank the financial support of FAPEMIG (Fundação de Amparo à Pesquisa do Estado de Minas Gerais) and the assistance of the Civil Engineering Department of the Universidade Federal de Viçosa. In addition, this study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001.

Disclosure statement

No potential conflict of interest was reported by the authors.