Development of 3D Printed Networks in Self-Healing Concrete

Abstract

This paper presents a new form of biomimetic cementitious material, which employs 3D-printed tetrahedral mini-vascular networks (MVNs) to store and deliver healing agents to damage sites within cementitious matrices. The MVNs are required to not only protect the healing agent for a sufficient period of time but also survive the mixing process, release the healing agent when the cementitious matrix is damaged, and have minimal impact on the physical and mechanical properties of the host cementitious matrix. A systematic study is described which fulfilled these design requirements and determined the most appropriate form and material for the MVNs. A subsequent series of experiments showed that MVNs filled with sodium silicate, embedded in concrete specimens, are able to respond effectively to damage, behave as a perfusable vascular system and thus act as healing agent reservoirs that are available for multiple damage-healing events. It was also proved that healing agents encapsulated within these MVNs can be transported to cracked zones in concrete elements under capillary driving action, and produce a recovery of strength, stiffness and fracture energy.

The Versatility of Polymeric Materials as Self-Healing Agents for Various Types of Applications: A Review

“… Mini-vascular networks (MVNs) of 3D-printed tetrahedral units (TETs) obtained from the authors of [ 25 ]. …”

Use of 3D printing to create multifunctional cementitious composites: review, challenges and opportunities

“…De Nardi et al [35] developed a so-called mini-vascular network system (MVN) for self-healing concrete. This system is, essentially, a compromise between the capsule-based and a vascular system: discrete tetrahedral MVNs are printed, filled with a healing agent (sodium silicate), and then distributed in the concrete mix.…”

Critical Aspects in the Development and Integration of Encapsulated Healing Agents in Cement and Concrete

“…1. The autogenous self-healing (Amenta et al 2020a) and all other approaches of autonomic self-healing, such as the use of mineral and expansive admixtures (Ahn and Kishi 2010;Roig-flores et al 2015), superabsorbent polymers (Mignon et al 2017;Mechtcherine et al 2021), vascular systems (Li et al 2020b;De Nardi et al 2020) and bacteria (Tziviloglou et al 2016;Chen et al 2019) were excluded from this review, as well as from the papers used in Fig. 1.…”