Greening effect of slag cement-based concrete: Environmental and ecotoxicological impact

Materials containing ground granulated blast furnace slag (GGBFS) display a transient green–bluecolor after demolding. This greening effect has been investigated for leaching behavior and ecotoxicological impact. Color of concretes pure pastes GGBFS was assessed with portable spectrophotometer, samples were then submitted to tank monolith test. Ecotoxicological tests conducted on reference sample green concrete at both natural adjusted pH 8.1. Main results support that the temporary GGBFS-containing materials no particular impact neither chemistry leachates, nor ecotoxicity. Additionally, alkaline leachates are main issue leached cement or based around 11.5–12.5. Alkaline is preponderant factor ecotoxicity sensitive organisms such as Daphnia magna , immobilization assay (48 h) resulting in 5.10 Toxic Units (TU) 12.50 against 1.38 TU 8.10. Furthermore, sulfides specific concentrated up 0.94 mmol m −2 having an ecotoxic living all trophic levels. At 8.10, have 4.85 Raphidocelis subcapitata growth (sulfides concentration 0.63 ) 3.0 sample. However, easily removed from solution by oxidation evaporation. • Greening not associated hazardous effects. (> 11) slag-based materials. The algae R. affected high unlike crustacean D. . GBFS contain 1 wt.% release eluates pastes. Sulfides quickly neutralized environment.