Autogenic vs. autonomic self-healing process in conservation mortars with crystalline admixture

Author(s): Maria Amenta, Matina Papaioannou, Marios S. Katsiotis, Dimitris Gournis, Vassilis Kilikoglou, Ioannis Karatasios
Paper category: Proceedings
Book title: Proceedings of the 5th Historic Mortars Conference
Editor(s): José Ignacio Álvarez, José María Fernández, Íńigo 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: 296-306
Total Pages: 11
Language : English

Abstract: Self-healing mortars can serve as a promising solution for enhancing the efficiency of conservation interventions, extending their service life and safeguarding built heritage. In this study, the autogenic self-healing capacity of natural hydraulic lime mortars is contrasted with the autonomic self-healing capacity of the same mixture with the addition of a crystalline admixture (CA). The self-healing capacity of both mixtures was evaluated by water permeability and capillary absorption tests. Moreover, the reduction of crack width due to self-healing was measured by means of optical microscopy, while the secondary healing phases produced inside the cracks were characterized and quantified by XRD and SEM/EDS. It was found that secondary healing products in NHL mixtures were mainly composed by calcite, portlandite and CSH phases whereas the addition of the crystalline admixture resulted in additional formation of sodium silicate hydrates. In terms of performance, it is shown that both mixtures partially recovered their water tightness due to the autogenic phenomenon, whereas the formation of CA healing products inside the micro- crack resulted in the enhancement of the autogenic self-healing mechanism which leads to a further reduction of water permeability.

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