A new bioslurry-induced restoration method via biomineralization for fragmented ceramic cultural relics

This study presents a new restoration method for fragmented ceramic cultural relics using bioslurry-induced biocementation via a microbially induced calcium carbonate precipitation (MICP) process. Bioslurry is highly urease active calcium carbonate crystals, which serve as filling and cementitious material with newly induced calcite precipitation when supplying cementation solution (urea and calcium source). With the pre-filling of bioslurry and newly induced calcite crystals, the fragmented ceramic can be connected and the gap along the fracture surface can be sealed. Due to the high urease active bacteria cells embedded in bioslurry, the ceramic restoration can be completed in 24 h with the optimal concentration of cementation solution of 1.6 M. Taking the advantage of bonding effect gained from newly induced calcite precipitation, the tensile strength was improved up to 0.92 MPa through a customized tensile strength test. This is satisfactory to ensure the stability and integrity of fragmented ceramic after bioslurry-induced restoration. A demonstrative restoration has been completed on fragmented ceramics from Ming Dynasty. With the good bonding strength and high stability of bioslurry-induced calcite precipitation, the proposed bioslurry-induced restoration method contributes valuable insights to the conservation of ceramic cultural relics. Other prospective applications include the restoration of masonry relics and bone relics.