Development of ultra-high performance concretes with self-healing micro/nano-additions. (1st May 2017)

• Record Type: Journal Article
• Authors: García Calvo, J.L.; Pérez, G.; Carballosa, P.; Erkizia, E.; Gaitero, J.J.; Guerrero, A.
• Is Part Of: Construction & building materials. Volume 138(2017)
• Page Start: 306
• Page End: 315
• Publication Date: 2017-05-01
• Subjects: Self-healing concrete -- High performance concrete -- Encapsulated additions -- Characterization -- Mechanical performance -- Durability; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2017.02.015
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Self-healing UHPCs are developed by using a set of two additions. Healing additions reduce the mechanical performance but refine the microporosity. An effective autonomous self-healing capacity is assessed in the fabricated UHPC. Self-healing capacity is not improved when increasing the additions content used. The crack width and the healing period influence the self-healing efficacy. Abstract: UHPC are developed in present paper incorporating an innovative self-healing system based on two micro/nano-additions: silica microcapsules containing epoxy sealing compound (CAP) and amine functionalised silica nanoparticles. Although CAP are well integrated within the cementitious matrix, their inclusion promotes a reduction in the mechanical performance so CAP could act as weak points. However, the inclusion of these additions refines pore distribution thus increasing the expected durability in aggressive media. An effective autonomous self-healing capacity is assessed/confirmed which is unexpectedly higher in the concretes with the lower healing additions content studied. This capacity depends on the crack width and the healing period considered.