A low carbon embedded low water/binder cement-based composites (LW/BCC) based on steel slag powder and microwave pre-curing: Experiments and Life Cycle Assessment (LCA)

This paper proposes a new design and preparation method for low carbon embedded low water/binder cement-based composites (LCE-LW/BCC), including experimental investigation and Life Cycle Assessment (LCA). To be specific, a recycled steel slag powder (SSP) is utilized to replace the cementitious material with high CO2 emission in normal LW/BCC, while an effective microwave pre-curing is employed to treat the developed samples at early age. After that, to determine the optimal parameters of microwave time duration (MTD) and microwave time zero (MTZ) for LW/BCC, its macro and micro performance are analyzed. Finally, the Life cycle Assessment (LCA) method is used to evaluate the whole cycle of low-carbon LW/BCC from production to service. The results show that a reasonable microwave pre-curing system can effectively shorten the curing cycle during the preparation of LW/BCC. A 1-minute microwave pre-curing during the induction period can improve the compressive strength of the sample by about 150% and increase its long-term strength. Based on LCA results, it can be noticed that the newly proposed method could decrease the natural resources depletion, ecotoxicity, ozone depletion and carbon emissions of LW/BCC by 94.71%, 90.36%, 87.3% and 84.45%, respectively.