Self- healing lime-based mortars using biological mechanisms and microvascular networks

Author(s): Cristina De Nardi, Magdalini Theodoridou, Philip Sim, Michael Harbottle, Anthoby D. Jefferson
Paper category: Proceedings
Book title: Proceedings of the 5th Historic Mortars Conference
Editor(s): José Ignacio Álvarez, José María Fernández, Íñigo Navarro, Adrián Durán, Rafael Sirera
ISBN: 978-2-35158-221-3
e-ISBN: 978-2-35158-222-0
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 319-329
Total Pages: 11
Language : English

Abstract: This study investigates the innovative application of calcite biomineralisation using specifically designed microvascular networks (MVNs) for the development of self-healing lime-based mortars to be used in both historic and contemporary structures. Four series of laboratory hydraulic lime-based mortar specimens were produced. The first comprised lime and aggregates only, while in the second, empty 3D printed MVNs were added. A MVN is a system of small diameter channels, able to break when damage occurs and release the hosted healing component. In the third series, Sporosarcina pasteurii were added to the mortar during mixing, while nutrient solution was stored in the MVNs. In order to better evaluate the efficiency of the MVNs with a non-biological healing agent, the fourth series MVNs were again included, this time containing sodium silicate. Damage was induced 14 days after casting by means of three-point bending loading in displacement control. All specimens were then stored in an incubator for five days of healing. Following the healing stage, the specimens were re-tested to determine the level of restored performance. The results showed the potential of the MVNs and the biological self-healing mechanism to restore efficiently the flexural strength of the lime-based mortars when damage occurred.

Online publication : 2019
Publication type : full_text
Public price (Euros) : 0.00