Title:
Concrete Attack by Feed Acids: Accelerated Tests to Compare Different Concrete Compositions and Technologies
Author(s):
Nele De Belie, Marcel Debruyckere, Dirk Van Nieuwenburg, and Benny De Blaere
Publication:
Materials Journal
Volume:
94
Issue:
6
Appears on pages(s):
546-554
Keywords:
acid resistance; acid resistance tests; blast furnace slag;
chemical attack; high-alumina cement; tests;
DOI:
10.14359/339
Date:
11/1/1997
Abstract:
Concrete in agricultural construction is often subjected to aggressive environmental conditions. For example, spilled meal-water-mixtures and silage effluent contain lactic and acetic acids, which degrade concrete. Through accelerated laboratory tests, the resistance of different concretes to these acids was studied. The variables were cement type, cement content, aggregate type, and consolidation. The data presented show a well-consolidated concrete with blast furnace slag cement and a fairly high cement content to be the most durable. High alumina cement was advantageous under certain conditions. Use of limestone aggregates reduced the effect of other variables and protected the hardened cement paste, particularly when portland cement was used. Three stages in attack were distinguished: 1) the concrete was weakened on the surface by chemical attack only, 2) the weak surface layer was removed by mechanical impact, 3) a part of the cement paste and (limestone) aggregates was dissolved. The measure of deterioration had an influence on the significance of differences between concrete samples. Therefore it is emphasized that care is required when comparing results from different investigations.