QUANTIFICATION THE FILLING OF MICROCRACKS DUE TO AUTOGENOUS SELF-HEALING IN CEMENT PASTE

Author(s): Jiayi Chen, Xian Liu, Guang Ye
Paper category: Proceedings
Book title: proceedings of the International RILEM Conference on Materials, Systems and Structures in Civil Engineering Conference segment on Service Life of Cement-Based Materials and Structures
Editor(s): Miguel Azenha, Ivan Gabrijel, Dirk Schlicke, Terje Kanstad and Ole Mejlhede Jensen
ISBN:978-2-35158-171-4
e-ISBN: 978-2-35158-173-5
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 745-754
Total Pages: 10
Language : English

Abstract: Microcracks play vital roles in the prediction of the service life of concrete structure. Because
microcracks in concrete structure are the preferential ingression channels for aggressive ions,
e.g., chloride, sulphate, etc. However, microcracks have potentials to self-heal autogenously
due to the continuous hydration of unhydrated cement, especially when ultra-/ high strength
concrete is used. To quantify the autogenous self-healing effects of microcracks in cement
paste, our experiment is designed to monitor the self-healing process of microcracks in
cement paste continuously by using optical microscope. The healing products are quantified
by image analysis with newly implemented software in MATLAB. The results indicate that
the microcracks are not filled evenly along the crack length and most healing products are
Ca(OH)2, which dissolve partly from the paste matrix and re-nucleate in the microcrack, in
addition to its counterpart from the continuous hydration of unhydrated cement. Furthermore,
the sample cracked at earlier age shows higher potential to heal, while the sample with
smaller crack width experiences greater filling efficiency. The obtained autogenous self-
healing mechanism will be used in the future simulation.

Online publication : 2016
Publication type : full_text
Public price (Euros) : 0.00