REPEATED AUTOGENOUS HEALING IN CEMENTITIOUS COMPOSITES WITH MICROFIBRES AND SUPERABSORBENT POLYMERS

Author(s): De Snoeck, D., Debaecke, S. and De Belie, N.
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
e-ISBN: 978-2-35158-149-0
Publication year: 2015
Pages: 61-68
Total Pages: 8
Language: English

Abstract: Cementitious materials are sensitive to crack formation and it would be beneficial if the material could reach again the original strength. Autogenous healing is an already-present feature in cementitious materials, but it is an inferior mechanism as it can only heal cracks up to 50 μm in the presence of water. Therefore, a cementitious material with synthetic microfibres and superabsorbent polymers (SAPs) is proposed. The microfibres will cause multiple crack formation and will result in a vast amount of small healable cracks. If superabsorbent polymers (SAPs) are also included, the self-healing can be promoted as SAPs are able to extract moisture from the environment and to provide it to the cementitious matrix for autogenous healing. But, if the building blocks are exhausted due to a first healing cycle, healing at second reloading may be less efficient. A crack can thus possibly heal only once. In this study, the ability of (promoted) autogenous healing to repeat itself is investigated by comparing the mechanical properties after performing repeated four-point-bending tests. Specimens are able to heal and to regain some of the mechanical properties after being preloaded and pre-cracked under four-point-bending. Even if those healed samples are reloaded for a second time, there is some regain in mechanical properties. If SAPs are added, there is even healing in an environment without liquid water (relative humidity of more than
90%), also in repeated healing actions. The cementitious composite with microfibres and SAPs thus shows partial repeatability of self-healing.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00