EAGER- Exploratory Study on Biomineralization in Cementitious Materials for Self-healing of Cracks

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

This Early-Concept Grant for Exploratory Research (EAGER) project intends to carry out a preliminary evaluation of the potential of biomineralization in cementitious materials for self-healing of cracks. The main objectives are to examine the survival and effectiveness of the chosen microorganisms in concrete, and to evaluate the effects of carbonate deposition on crack remediation. Microorganisms induced carbonate deposition will be studied in simple test tube experiments and in mortar specimens. Scanning electron microscopy and X-ray diffraction will be used for detailed characterization of the deposits and to investigate if enough carbonate deposition can be achieved to fill up cracks. Fracture study will be performed to evaluate if carbonate deposits can promote regain of fracture toughness. Quasi-brittle nature of concrete and its tendency to crack makes maintenance of concrete structures a costly and labor intensive process. Thus research has been undertaken worldwide to develop a smart infrastructure material which can heal cracks. However, the perfect material that satisfies this need is yet to be developed. In recent years it has been reported by few researchers that bio-mineralization technique is promising based on its effect on compressive strength. However, increase in compressive strength is not a sufficient proof that the bond between newly developed carbonate and cracked material is sufficient to regain part of the strength lost due to cracking. This EAGER proposal carefully develops an experimental plan to evaluate potential of bio-mineralization. If this preliminary study shows promise it could pave the way for future work on biomineralization to establish a transformative concept of self-healing construction materials.