Concrete Fracture Energy Increase by Embedding Capsules with Healing Ability: The Effect of Capsules Nature

Author(s): Eleni Tsangouri, Francisco A. Gilabert, Dimitrios G. Aggelis, Nele De Belie, Danny Van Hemelrijck
Paper category: Proceedings
Book title: Proceedings of the 2nd International RILEM/COST Conference on Early Age Cracking and Serviceability in Cement-based Materials and Structures Volume 1
Editor(s): Stéphanie Staquet and Dimitrios Aggelis
Publisher: RILEM Publications SARL
Publication year: 2017
Pages: 175-182
Total Pages: 8
Language : English

Abstract: Concrete is the basic material of infrastructures since it is cost-effective, efficiently produced and strong. Despite its popularity, under service-loads the concrete matrix suffers from flaws that can be crucial for its durability. To overcome the shortcoming in durability, concrete is traditionally reinforced by steel or its mixture is modified by introducing additives that enrich the autogenous crack closure. Nowadays, an alternative solution is proposed namely autonomous healing. Repair polymer agent is encapsulated into tubes and embedded into concrete during mixture. The tubes break as soon as a crack wider than 100 μm is propagated across them. Only at this moment, the agent is released and polymerized. The crack void is sealed and repaired (mechanical features restored as well). The previous years, researchers at the Dept. Mechanics of Materials and Constructions, VUB have studied the mechanical performance of newly developed healing systems and evaluated their repair efficiency. In this study, an additional benefit of autonomous healing is assessed: the short or long tubes contribute as local reinforcement of concrete under tensile load and enhance the fracture toughness. The energy release rate and other fracture mechanics parameters are measured for plain concrete beams tested under three-point bending. The reference case (concrete carrying no healing system) is compared to cases at which different encapsulation systems are applied. Additionally, the study of fracture is correlated to the findings of inspection with different non-destructive techniques. The effect of tubes design (geometry, shape, material) on the fracture toughness is studied leading to the most promising healing system.

Online publication : 2017
Publication type : full_text
Public price (Euros) : 0.00

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