Use of bacterial binder in repair mortar for micro-crack remediation

Sirt Çiplak E., Bilecen K., Akoglu K. G., Guchan N.

APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, cilt.108, ss.1-15, 2023 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 108
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1007/s00253-023-12507-2
  • Dergi Adı: APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, ABI/INFORM, Applied Science & Technology Source, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, Compendex, Computer & Applied Sciences, EMBASE, Environment Index, Food Science & Technology Abstracts, Geobase, MEDLINE, Pollution Abstracts, Veterinary Science Database
  • Sayfa Sayıları: ss.1-15
  • Anahtar Kelimeler: Calcite, Bacteria, Micro-crack, Biological mortar, Conservation, Travertine, CALCIUM-CARBONATE PRECIPITATION, YELLOWSTONE-NATIONAL-PARK, MAMMOTH HOT-SPRINGS, CULTURE EXPERIMENTS, CEMENT MORTARS, TRAVERTINE, CAVE, SOIL, LIMESTONE
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Micro-cracks are one of the types of stone deterioration which can propagate and lead to surface detachments and larger cracks in the long run. The present study developed a sustainable and environmentally friendly infill material—biological mortar (BM), as an alternative to conventional approaches. Using a biomineralization approach, this BM was explicitly designed for healing micro-cracks (less than 2 mm) in historic travertines. To this end, the mortar was prepared using a calcifying Bacillus sp. isolated from thermal spring water resources in Pamukkale Travertines (Denizli), stone powder gathered from travertine quarries in the vicinity, and a triggering solution specifically designed to set off calcium carbon- ate precipitation reaction. After setup, BM was applied to micro-cracks of artificially aged test stones for testing. Scanning electron microscopy revealed calcium carbonate-coated Bacillus sp. bodies in the BM matrix, optical microscopy showed secondary calcite minerals throughout the BM applied micro-cracks, and stereomicroscopy and nanoindentation analyses demonstrated bonding of BM with stone due to microbial calcification activities. Furthermore, BM and original material contact showed a continuous and coherent structure in all samples. Within this context, BM could be considered a promising and alternative approach for the remediation of micro-cracks of historic stones.