A NEW TEST METHOD TO EVALUATE THE RESISTANCE OF CEMENTITIOUS MATERIALS EXPOSED TO BIOGENIC ATTACK IN SEWER NETWORKS
Author(s): Lavigne, M. P., Bertron, A., Cockx, A., Jean-Noël, F., Escadeillas, G. and Paul, E.
Paper category: Conference
Book title: XIII International Conference on Durability of Building Materials and Components - XIII DBMC
Editor(s): Marco Quattrone, Vanderley M. John
Print ISBN: none
Publication year: 2015
Total Pages: 9
Abstract: An innovative test method for evaluating the biodeterioration of cement linings in sewer-like conditions was designed and implemented. The development of the test, involving a lab-scale pilot design, was based on (i) identification of the limiting phenomena, (ii) analysis of the sulfur cycle in the condensate phase, (iii) experimental identification by mass balance of a substitute sulfur substrate for microorganisms, and (iv) enhancement of the local biological acidification by control of the environmental conditions applied to the wall of various pipes. This step ensured, with a non-specified inoculum (activated-sludge microbial consortium), immediate sulfur-oxidizing activity, its intensification and its stabilization.
Preliminary work enabled thiosulfate to be identified as an intermediate substrate for biological acidification, by comparison between a biotic pipe and an abiotic pipe covered with CAC lining. Then, CAC or BFSC cement mortars were evaluated under the same biotic conditions to test the pilot configuration. The resistance of the cement linings during the test was evaluated by monitoring the pH and the Ca and Al concentrations of the leaching solutions. At the end of the test, the physical, chemical and microstructural changes of the cement mortars were investigated using XRD, SEM coupled to EDS and EPMA analyses in order to identify the mechanisms of alteration of the matrices.
Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00