Bond Enhancement of Repair Mortar via Biodeposition

Published

September 4, 2017

Author(s)

Didier Snoeck, Jianyun Wang, Dale P. Bentz, Nele De Belie

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 substrate is promoted via the biodeposition of calcium carbonate by a ureolytic 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 mortar 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.

Proceedings Title

INTERNATIONAL CONFERENCE ON ADVANCES IN CONSTRUCTION MATERIALS AND SYSTEMS

Volume

2

Conference Dates

September 3-8, 2017

Conference Location

Chennai, IN

Pub Type

Conferences

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Keywords

Calcium carbonate, bond strength, slant shear, biodeposition.

Citation

Snoeck, D. , Wang, J. , Bentz, D. and De Belie, N. (2017), Bond Enhancement of Repair Mortar via Biodeposition, INTERNATIONAL CONFERENCE ON ADVANCES IN CONSTRUCTION MATERIALS AND SYSTEMS, Chennai, IN, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=922614 (Accessed December 5, 2024)