Mode of innovative green production for concrete engineering: life cycle assessment of accelerators prepared from aluminum mud wastes

In this study, two types of liquid alkali-free accelerators were prepared by aluminum sulfate (AF 1 ) and aluminum mud wastes (AF 2 ), and the life cycle assessment (LCA) in the preparation of AF 1 and AF 2 was compared. The LCA was considered from cradle to gate including raw materials used, transportation, and accelerator preparation based on the method ReCiPe2016. The results indicated that AF 1 had a higher environmental impact in all midpoint impact categories and endpoint indicators than that of AF 2 , and AF 2 reduced 43.59% emission of CO 2 , 59.09% emission of SO 2 , 71% consumption of mineral resources, and 46.67% consumption of fossil resources than that of AF 1 respectively. As an environment-friendly accelerator, AF 2 had a better application performance than traditional accelerator AF 1. When the dosage of accelerators was 7%, the initial setting times of cement pastes containing AF 1 and AF 2 were 4 min 57 s and 4 min 04 s respectively, the final setting times of cement pastes containing AF 1 and AF 2 were 11 min 49 s and 9 min 53 s respectively, and the compressive strengths at 1 d of mortars containing AF 1 and AF 2 were 7.35 MPa and 8.33 MPa respectively. This study aims to provide technical feasibility and environmental impact assessment for exploring new avenues of preparing environment-friendly liquid alkali-free accelerators with aluminum mud solid wastes. It has great potential in reducing carbon and pollution emissions and has a greater competitive advantage due to great application performance.