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标题：Effect of sulphate corrosion on the durability of air-entrained cement mortars
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作者：Monika Knap ; Wojciech Piasta
期刊名称：MATEC Web of Conferences
电子版ISSN：2261-236X
出版年度：2018
卷号：174
DOI：10.1051/matecconf/201817402012
语种：English
出版社：EDP Sciences
摘要：Sulphate corrosion is a complex sequence of chemical and physical processes that, when the aqueous sulphate solutions are exposed for a sufficiently long time, irreversibly destroys the microstructure of cement paste. In order to determine the durability of Portland cement mortars, mortar resistance tests were carried out on a 5% solution of sodium sulphate by measuring linear deformations. The tests included 1 series of non air-entrained mortars and 3 series of air-entrained mortars with air content: 7%, 10% and 13%. The biggest deformations were observed for non air-entrained samples, the smallest for mortar with an air content of 13%. Compressive strength tests of mortars after 28 days and 80 weeks of residence in a solution of sodium sulphate were also carried out. For all mortars, the strength measured after 80 weeks immersion in Na2SO4increased in relation to the strength after 28 days of maturation. Observations of the cement mortar microstructure using a scanning electron microscope (SEM-EDS) showed that ettringite was present in both the C-S-H structure and the air pores. By means of XRD analysis, the occurrence of crystalline materials was detected. Based on the research, it was found that air-entrained cement mortars showed greater durability in the context of sulphate corrosion.