AUTHOR=Tziviloglou Eirini , Wiktor Virginie , Jonkers Henk M. , Schlangen Erik 

TITLE=Selection of Nutrient Used in Biogenic Healing Agent for Cementitious Materials

JOURNAL=Frontiers in Materials

VOLUME=Volume 4 - 2017

YEAR=2017

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2017.00015

DOI=10.3389/fmats.2017.00015

ISSN=2296-8016

ABSTRACT=Biogenic self-healing cementitious materials target on the closure of micro-cracks with precipitated inorganic minerals originating from bacterial metabolic activity. Dormant bacterial spores and organic mineral compounds often constitute a biogenic healing agent. The current paper focuses on the investigation of the most appropriate organic carbon source to be used as component of a biogenic healing agent. It is of great importance to use an appropriate organic source, since it will firstly ensure an optimal bacterial performance in terms of metabolic activity, while it should secondly affect the least the properties of the cementitious matrix. The selection is made among three different organic compounds, namely calcium lactate, calcium acetate and sodium gluconate. The methodology that was used for the research was based on continuous and non-continuous oxygen consumption measurements of washed bacterial cultures and on compressive strength tests on mortar cubes. The oxygen consumption investigation revealed a preference for calcium lactate and acetate, but an indifferent behaviour for sodium gluconate. The compressive strength on mortar cubes with different amounts of either calcium lactate or acetate (up to 2.24% per cement weight) was not or it was positively affected when the compounds were dissolved in the mixing water. In fact, for calcium lactate the increase in compressive strength reached 8%, while for calcium acetate the maximum strength increase was 13.4%.