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.