‘Microbial mortar’-restoration of degraded marble structures with microbially induced carbonate precipitation

• Published in: Construction & building materials Vol. 180; pp. 44 - 54
• Main Authors: Minto, James M., Tan, Qian, Lunn, Rebecca J., El Mountassir, Gráinne, Guo, Hongxian, Cheng, Xiaohui
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 20-08-2018
• Subjects: Marble restoration; Micro-continuum flow modelling; Microbially induced carbonate precipitation; X-ray CT; Marble restoration; X-ray CT; Microbially induced carbonate precipitation; Micro-continuum flow modelling
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2018.05.200

•Microbial mortar can successfully restore degraded marble.•Reagent transport evolved with each treatment cycle.•Micro-continuum flow simulation of 3D X-ray data revealed changing flow paths.
To evaluate a restoration strategy for highly degraded marble structures, microbially induced carbonate precipitation (MICP) has been employed to reduce porosity and permeability in a column filled with coarse crushed marble. A 3D X-ray tomography scan revealed the spatial variation in porosity throughout the column and tracer breakthrough curves, recorded at intervals during treatment, enabled derivation of core-scale fluid transport properties and their alteration by precipitating carbonate. Micro-continuum scale flow modelling based on the X-ray data indicated that treatment led to changes in the pore network structure with flow increasingly focused into a smaller number of faster flowing open channels.