POTENTIAL OF BIOLOGICAL MORTAR FOR MICRO-CRACK REMEDIATION OF CALCAREOUS STONES IN HISTORICAL MONUMENTS

Abstract

Since the early ages, first human beings, then architects and civil engineers have preferred stones for the construction of historic monuments and buildings due to their durable nature. But in the course of time, these stones have inescapably been faced with different kinds of weathering processes because of several biotic and abiotic weathering factors. In calcareous stones, micro-cracks/fissures are the common deterioration forms resulting from these weathering processes, and in the long term, they affect the durability of the structure. The survival of monuments and buildings is substantially related with the protection and the conservation of the materials from which they are constructed. To this end, several treatment approaches have been developed for the micro-crack remediation of these materials but there is still room for improvement to fulfill multiple aspects of remediation studies. Although many studies and applications can be found on biomineralization techniques and approaches, few studies have been conducted on biological mortars. This review highlights the potential of biological mortar acquired through biomineralization as an alternative bio-based repair material for the healing of micro-cracks of historic calcareous stones. Promising findings from laboratory analyses and field observations of biological mortars are given with a brief discussion on limitations, challenges, and future works in relation with remediation of micro-cracks of stones.