DURABILITY OF CEMENT-REDUCED ECO-FRIENDLY CONCRETES AGAINST SULFATE ATTACK
Author(s): Hainer, S., Rezvani, M., Baldermann, A., Proske, T. and Mittermayr, F.
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: 8
Abstract: The durability of two newly developed cement-reduced eco-friendly concretes with high limestone powder content and low water-powder ratios was recently successfully tested against carbonation and slight freeze-thaw attack by Proske et al. . Mittermayr et al.  demonstrated the resistance of these eco-concretes against sulfate attack which will be highlighted in this study.
Mortar specimens with the same paste composition than that of the eco-friendly concretes were stored in a sodium sulfate solution and Ca(OH)2 reference solution for 200 days at 8°C, together with reference mortar samples that reflect conventional concrete compositions. Several analytical techniques were applied after immersion in order to assess mechanical, mineralogical, and microstructural alteration features related to sulfate attack. This includes expansion rate and residual compressive strength measurements, combined with X-ray diffraction and electron microprobe analyses.
Gypsum, bassanite and ettringite obviously caused the main damage as their occurrences are linearly correlated to the expansions rates of the mortar specimens. In all test specimens no thaumasite was found in spite of potentially favorable conditions. This may be related to the evolution of the experimental solutions and the competing formation of calcite and vaterite. Both eco-friendly mixtures exhibited a better sulfate resistance than their respective reference samples and are therefore suggested to be applicable sulfate-loaded environments.
Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00