Document Type : Primary Research paper
Assistant Professor Department of Civil Engineering Nehru Institute of Technology
Cement production is a polluting process for nature. For this reason, new
types of concrete which can be produced with recycled materials and
without cement continue to be investigated. On the other hand; cracks in
structural elements reduce the strength and durability of a building.
Extending service life of buildings has eliminated the cost of rebuilding
and thus, contributed to both the economy and the ecosystem. Due to
this, research on crack healing in Portland cement concretes with various
bacteria is continuing for some time. However, there are not enough
studies in literature regarding the improvement of metakaolin-based
geopolymer mortars produced without using cement by urolytic bacteria.
The parameters of temperature, pH and void ratio of bacterial
geopolymer mortar affect the viability of bacteria. For example, pH value
of the medium required for the survival of bacteria is, generally around
nine. During the production of geopolymer concrete, a sudden increase in
high alkali environment occurs due to use of activators. This reduces the
survival rate of bacteria added to the mixture during the production of
geopolymer mortar. In this study, the most suitable environment for
geopolymer mortar, and the conditions for the bacteria to survive until
the end of the curing process for the mortar to be strengthened were
investigated. Analyses on the effects of urolytic bacteria and geopolymer
mortar healing process on mechanical strength of the mortar were
conducted. Sporosarcina Pasteurii were used for the self healing process.
Various mixtures of geopolymer mortars were cured under different
environmental conditions to observe changes in their mechanical strength
and water absorption capacity. As the result of the study, the most
suitable mixture ratio and curing medium were identified. It was
observed that the nutrient, ensuring the life cycle of the urolytic bacteria,
had no negative effect on the mechanical strength of mortar and reducedcapillary water absorption of the mortar.
This study is a specific text in the literature that analyzes bacterial curing
conditions and the effect of improving geopolymer mortar.