Thesis defence X. Ma: sulfate attack

12 November 2018 10:00 - Location: Aula, TU Delft - By: webredactie

Cement paste degradation under external sulfate attack. An experimental and numerical research. Promotor: H.E.J.G. Schlangen (CiTG).

Chemical degradation of cementitious materials is a serious threat to the durability and performance of concrete structures. External sulfate attack is one of the situations that may cause gradual but severe damage. In this thesis, an attempt is made to increase the body of knowledge related to cement paste expansion and degradation due to external sulfate attack. Laboratory experiments and numerical simulations were used during the study. Small cement paste pipes with a wall thickness of 2.5 mm were prepared and immersed in sodium sulfate solutions with two types of sulfateconcentrations. Three types of longitudinal restraints were applied on the specimens before exposure. The expansions, generated stress, pore size distribution, sulfur distribution and crack pattern were measured and analyzed. SEM-EDS microanalysis and image analysis were applied. The processes of specimen expansion and crack development were investigated experimentally and numerically. Also, the experimental setup and techniques employed in this study can be used in the same or similar way for further studies on external sulfate attack or some other degradation problems.

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For access to theses by the PhD students you can have a look in TU Delft Repository, the digital storage of publications of TU Delft. Theses will be available within a few weeks after the actual thesis defence.