Testing and modelling biogenic sulfuric acid corrosion of concrete sewer pipes in function of aggregate type, cement type and production method

Title: Testing and modelling biogenic sulfuric acid corrosion of concrete sewer pipes in function of aggregate type, cement type and production method
Author(s): N. De Belie, J. Monteny, E. Vincke, A. Beeldens
Paper category : conference
Book title: 2nd International RILEM Workshop on Life Prediction and Aging Management of Concrete Structures
Editor(s): D.J. Naus
Print-ISBN: 2-912143-36-5
e-ISBN: 2912143780
Publisher: RILEM Publications SARL
Publication year: 2003
Pages: 195 - 204
Total Pages: 10
Nb references: 8
Language: English

Abstract: A new procedure for microbiological tests, simulating biogenic sulfuric acid corrosion in sewerage systems, is presented. The effect of production method (affecting W/C ratio), cement type and aggregate type on the resistance of commercially produced sewer pipes or inspection pits was investigated. The aggregate type influenced concrete degradation to the largest extent. Concrete with limestone aggregates showed a more limited decrease in thickness than concrete with inert aggregates. Examination with the scanning electron microscope suggested that the presence of the limestone aggregates created a protective micro-environment, resulting in a less porous transition zone. Concrete types produced by centrifugation or immediate form removal showed a higher resistance than those hardened in the form. This was ascribed to the higher water/cement (W/C) ratio of these specimens. In contrast to previous chemical experiments with sulfuric acid on concrete produced in the laboratory, Portland cement concrete performed better than slag cement concrete. This is ascribed to a limited curing of commercial concrete products and/or a more rapid colonisation of slag cement samples by micro-organisms. An improvement of the Pomeroy model for concrete degradation was suggested, in which water absorption (as a measure for porosity) was added as an important parameter, next to alkalinity.

Online publication: 2003-04-02
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143780.019