Blended cement is a bad recommendation for magnesium sulfate attack

Title: Blended cement is a bad recommendation for magnesium sulfate attack
Author(s): A.M. Diab, A.E. M.Awad, H.E. Elyamany, A.E.M. Abd Elmoty
Paper category : conference
Book title: International Conference on Microstructure Related Durability of Cementitious Composites
Editor(s): W. Sun, K. van Breugel, C. Miao, G. Ye and H. Chen
Print-ISBN: 978-2-35158-065-3
e-ISBN: 978-2-35158-084-4
Publisher: RILEM Publications
Publication year: 2008
Pages: 445 - 454
Total Pages: 10
Nb references: 10
Language: English

Abstract: The service life of concrete structures depends on the environmental conditions and on the quality of concrete. Durability of concrete to sulfate attack is one of the environmental problems. Now, the most famous method to enhance the sulfate resistance of concrete is the use of additions such as natural pozzolans, fly ashes or silica fume. A lot of researches cover the effect of mineral admixtures on sodium sulfate resistance. From all these studies, the final conclusion was the use of silica fume as cement replacement enhances the performance of cement pastes and mortars to sodium sulfate attack. The performance of mineral admixtures on resisting the magnesium sulfate attack gives confusion data because of some researchers concluded that the silica fume has a negative effect on enhancing the concrete resistance to magnesium sulfate attack and others concluded the opposite. In this research work, an overall long term study to evaluate the performance of mortars with mineral admixtures as cement replacement to resist magnesium sulfate attack. Silica fume and metakaolin were used as mineral admixtures. The used percentages of cement replacement were 0, 10, 15, and 25%.
Type I and Type V Portland cement were used with 0.5 and 0.4 w/cm ratio. The mortars specimens were subjected to 5% magnesium sulfate for 700 days. The weight loss, compressive strength, and expansion strain were used to evaluate the performance of the mortars to resist magnesium sulfate attack. From the test results, the mortars specimens made with mineral admixtures either silica fume or metakaolin had weight loss, length change, and compressive strength loss greater than those of mortars without mineral admixtures.

Online publication: 2009-06-09
Publication type : full_text
Public price (Euros): 0.00