EVALUATIONS OF EFFECTS OF NUTRIENTS, CALCIUM PRECURSORS, AND BACTERIA ON MECHANICAL PROPERTIES OF MORTAR SPECIMENS

Author(s): Chien-Chung Chen, Maeve B. Cucolotto, Marko Balac, Sung Wang, Chen-Hsuan Chiu and W.T. Evert Ting
Paper category: Proceedings
Book title: Proceedings of the Final Conference of RILEM 253-MCI Microorganisms-Cementitious Materials Interactions Volume II
Editor(s): Alexandra Bertron and Henk Jonkers
ISBN: 978-2-35158-207-7 (Set)
ISBN: 978-2-35158-210-7 (Volume 2)
e-ISBN: 978-2-35158-206-0
Publisher: RILEM Publications SARL
Publication year: 2018
Pages: 455-463
Total Pages: 308
Language : English

Abstract: Bacteria-based self-healing concrete incorporates bacterial spores, nutrients, and calcium sources, into the concrete mixture to provide self-healing capability. Various bacteria-based healing agents, comprising different types of bacteria, nutrients, and calcium sources, have been utilized in the past for the development of self-healing concrete. As nutrients and calcium sources are needed for bacterial growth and calcium carbonate precipitation, types and dosages of nutrients and calcium sources to be incorporated in the self-healing agent may influence effectiveness of concrete self-healing. Additionally, self-healing concrete must possess satisfactory mechanical properties. While bacteria spores, nutrients, and calcium sources provide self-healing properties to concrete, they may influence concrete strength and workability. Therefore, it is essential to identify effects of different nutrients and calcium sources on concrete properties. This paper experimentally studied the effects of bacterial spores, various nutrients, and calcium sources on compressive strength of mortar samples. Nutrients and calcium sources selected in the experimental study included urea, yeast extract, tryptic soy broth, calcium lactate, calcium nitrate, and calcium chloride. Compressive strengths of mortar cubes with three different dosages of each selected material were obtained and compared with those of control samples. While bacterial spores exhibited no significant impacts on the compressive strength of mortar specimens, results from this study showed that compressive strengths of mortar cubes were affected by the types and dosages of nutrients and calcium sources. All three nutrients studied showed some degrees of negative impacts on the compressive strength of mortar cubes. While two of the calcium precursors showed positive impacts on the compressive strength of mortar cubes, one of the calcium precursors exhibited an adverse effect on the compressive strength of mortar cubes.

Online publication : 2018
Publication type : full_text
Public price (Euros) : 0.00