Roller-compacted concrete pavement made of Electric Arc Furnace slag aggregate: Mix design and mechanical properties

Abstract

This research investigates the feasibility of using Electric Arc Furnace (EAF) slag aggregate and fly ash in Roller-compacted concrete pavement (RCCP). After treatment process, EAF slag aggregate was examined the potential expansion caused by hydration reactions and alkali-silica reactions. The test results showed that EAF slag aggregate is stable the volume and can be used in concrete. In the RCCP mixtures, EAF slag was used as a substitute for natural coarse aggregates with three percentages (i.e. 0%, 50% and 100%) and cement was partially replaced by fly ash at three content levels (i.e. 0%, 20% and 40%). The optimum moisture content of RCCP mixtures containing EAF slag aggregate and fly ash were determined by the soil compaction method. The unit weight and mechanical properties (i.e. compressive strength, splitting tensile strength and elastic modulus) of RCCP were examined through testing program. As a result, the fresh and hardened unit weight are similar to those of conventional RCCP. Moreover, the compressive strength, splitting tensile strength and elastic modulus of RCCP decreased with increasing EAF slag aggregate ratio at all ages. Nevertheless, the conjunction of EAF slag aggregate and 20% fly ash in the RCCP mixtures improved the mechanical properties in the long-term ages. This study has proved that the RCCP containing EAF slag aggregate and fly ash can be employed to develop pavements as an exposed wearing surface. In addition, a predicting model was proposed to calculate compressive strength of RCCP.