Studies on efficacy of biocementation of cement mortar using soil extract

摘要

Haphazard increase in population has resulted in an enormous increase in construction demands. Huge amounts of resources are utilized for these gigantic constructions. Thus, chemical and non-biodegradable additives are over consumed in order to strengthen and protect these constructions. Such practices adversely affect the environment and thus the production of environment-friendly strength improve-ment materials is of utmost importance to achieve sustainability goals. Biocementation is one of the most emphasized green practices, which uses bacterial metabolisms to produce calcium carbonate mineral that has extraordinary ability to strengthen, heal and protect construction materials. In spite of having pronounced potential to improve and repair construction materials, biocementation has some drawbacks from practicability point of view. The cost and maintenance of nutrients required for the growth of microorganisms are the factors that limit practicability of biocementation. Present study focuses on replacement of expensive nutrients by rhizospheric soil extract for the growth of ureolytic bacteria, and to use them to boost the mechanical properties of cement-mortar by microbially induced calcium carbonate precipitation (MICCP) or biocementation. Results showed that the soil extract was as effective as conventional growth nutrients to grow the ureolytic bacteria which can be used for the process of biocementation to strengthen the construction materials. (C) 2020 Elsevier Ltd. All rights reserved.