Influence of biodeterioration on the mechanical properties of cement mortar

Author(s): Jorge F. Márquez-Peñaranda, Mauricio Sánchez-Silva, Johana Husserl and Emilio Bastidas-Arteaga
Paper category: Proceedings
Book title: Proceedings of the Final Conference of RILEM 253-MCI Microorganisms-Cementitious Materials Interactions Volume I
Editor(s): Alexandra Bertron and Henk Jonkers
ISBN: 978-2-35158-207-7 (Set)
ISBN: 978-2-35158-209-1 (Volume1)
e-ISBN: 978-2-35158-206-0
Publisher: RILEM Publications SARL
Publication year: 2018
Pages: 57-67
Total Pages: 288
Language : English

Abstract: This work addresses the problem of concrete deterioration over time as a result of microbial attack (concrete biodeterioration). To achieve such objective, a novel experimental work directed to determine the effect of microbial attack on both physical and mechanical concrete properties was developed. A set of 13 mm x 13 mm x 10 mm mortar Portland type I cement were inoculated with Hallothiobacillus neapolitanus NCIMB 8454 (H.n.) and Acidithiobacillus thiooxidans NCIMB 9112 (A.t.) using aseptic and non-aseptic condition. Samples were exposed in two different experiments to peaks of 131 and 222 ppmv H2S, 0.3%CO2, for 300 and 153 days respectively.
The analysis of porosity and strength changes in cement mortar from biodeterioration is a novel contribution of this study. Changes in porosity using mercury intrusion porosimetry, compressive strength and dry weight were measured. Total porosity loses up to 32% and 13% were observed after exposition of inoculated samples and non-inoculated samples, respectively. Major changes were observed in pore-sizes between 10 nm and 5000 nm, slightly smaller changes in pore sizes larger than 5000 nm and no changes in pores smaller than 10 nm. Inoculated samples showed a pronounced strength and weight loss after five months of exposure to bacteria compared to non-inoculated samples. As a general conclusion, biodeterioration produced adverse effects in all the measured mechanical properties of exposed cement mortar samples.

Online publication : 2018
Publication type : full_text
Public price (Euros) : 0.00