Application of electric arc furnace slag for stabilisation of different tropical soils
Emerson Cordeiro Lopes, Taciano Oliveira da Silva, Heraldo Nunes Pitanga, Leonardo Gonçalves Pedroti, José Maria Franco de Carvalho, Gustavo Henrique Nalon, Gustavo Emílio Soares de Lima, Mateus Henrique Ribeiro Rodrigues
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 (FEAF) as stabilising agents of two different soils Tests for geotechnical characterisation of soils and chemical, physical, and morphological characterisation of FEAF were carried out. Natural soils and soil-FEAF mixtures were subjected to standard Proctor compaction, unconfined compression strength (UCS), California Bearing Ratio (CBR), and resilient modulus (RM) tests. FEAF 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 FEAF (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% FEAF was 60–65% of CBR index of A-2-7(0) soil containing 15% FEAF. Similar reductions (27–29%) in CBR swelling were observed in both soils. Incorporation of 15% FEAF 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 FEAF improved soils’ performance, enabling their use in pavement design and earthworks.