Bond Enhancement of Repair Mortar via Biodeposition

Author(s): Didier Snoeck, Jianyun Wang, Dale P. Bentz and Nele De Belie
Paper category: Proceedings
Book title: Proceedings of International Conferences (ICACMS) Advances in Construction Materials and systems Vol 2
Editor(s): Manu Santhanam, Ravindra Gettu, Radhakrishna G. Pillai, Sunitha K. Nayar
ISBN: 978-2-35158-194-0
e-ISBN: 978-2-35158-191-9
Publisher: RILEM Publications SARL
Publication year: 2017
Pages: 526-532
Total Pages: 7
Language : English

Abstract: The bond between repair mortars and existing concrete substrates is critical for the long-term performance and durability of the repaired structure. The carbonation state of the substrate is one of the parameters that may affect this bond strength. The type of calcium carbonate polymorph (calcite, aragonite or vaterite) affects the nucleation and growth of cement hydration products. In this study, carbonation of the mortar substrate is promoted via the biodeposition of calcium carbonate by aureolytic bacteria strain previously employed in bioconsolidation. X-ray diffraction and scanning electron microscopy were used to examine the interfaces between the repair material and the substrate, as well as the polymorph of the deposited calcium carbonate. It appeared that the approximately 50 μm thick biodeposition film on the mortar surface mostly consisted of calcite and vaterite. The deposited crystals were full of bacterial imprints. Both the repair material and the substrate tended to show a good adherence to that layer. The bond, as assessed in this study by slant shear specimen testing, was improved by the presence of the biodeposition layer.

Online publication : 2017
Publication type : full_text
Public price (Euros) : 0.00