Enlightenment of ancient Tabia for sustainable construction material manufacture by accelerated CO₂ treatment

Inspired by the wisdom of Tabia, an ancient building material with superior mechanical properties, this paper utilized accelerated CO₂ mineralization (CM) method to treat silty waste soil (SWS) with active lime after the pressing forming process for construction block manufacture. The influence of Ca(OH)₂ content and curing duration were explored. Results indicate that the generated CaCO₃ could fill pores and improve strength of the SWS blocks after CM treatment. At the optimal Ca(OH)₂ content of 15 % and curing duration of 24 h, the CM-SWS blocks possessed the compressive strength of 12.8 MPa, CO₂ emissions of 84.59 kgCO₂/m³ and cost of 196.26 CNY/m³, comparable with or superior than the commercial blocks. The findings would deepen the mechanistic understandings of CM treatment in material reinforcement, and pave a proof-of-concept path to sustainably upgrade the SWS of poor engineering performance for building material production.