A NEW PERFORMANCE TEST TO ASSESS THE POTENTIAL DELETERIOUS EFFECT OF SULPHIDE-BEARING AGGREGATES FOR CONCRETE

Author(s): Duchesne, J., Rodrigues, A. and Fournier, B.
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
e-ISBN: 978-2-35158-149-0
Publication year: 2015
Pages: 214-221
Total Pages: 8
Language: English

Abstract: Recently, important damages in concrete containing sulfide-bearing aggregates were observed in the Trois-Rivières area (Québec, Canada). More than 1000 residential owners and many commercial buildings have faced serious issues related to the deterioration of their concrete housing foundations and slabs. The problematic aggregate is an anorthositic gabbro containing sulfide minerals. These sulfide minerals are unstable in the presence of oxygen and humidity resulting in an oxidation reaction; and pyrrhotite is known as one of the most “reactive” sulfide minerals.

The goal of this research is to develop a performance test to assess the potential deleterious effect of different sulfide-bearing aggregates for concrete. So far, the chemical approach, using a measure of the total sulfur content is a tool used for the rapid detection of the presence of iron sulfides in aggregate. This technique cannot identify the type of sulfide present and serves only as a screening test and further testing is needed. In the approach proposed, the next step is a newly-developed mortar bar expansion test where the bars are subjected to a cyclic exposure conditioning regime involving wetting and drying cycles in an oxidizing agent keeping temperature and humidity conditions that are favorable to oxidation reaction.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00