About this Research Topic
The structural integrity of all civil infrastructure is achieved with the utilisation of individual elements which are designed to respond sufficiently when exposed to one or more mechanical or environmental actions. All the design codes and guidelines focus on how structures, comprised of individual elements, will be able to retain structural resilience when exposed to adverse effects. The material performance is not considered a priority and degradation is an inevitable process that requires maintenance regimes. In the UK alone this translates to a cost of ~£40 billion/year on repair and maintenance of existing, mainly concrete, structures. The American Society of Civil Engineers in a recent report estimates that the maintenance of US civil infrastructure requires an investment of $3.6 trillion over a period of seven years in order to return to the 1988 quality standards.
Concrete has gained a lot of attention the last 15 years as far as the development of self-healing mechanisms are concerned. Significant contributions have been done by research groups globally for the development of both autogenic and autonomic self-healing actions. As such, the work to-date includes the development of special cementitious blends with improved autogenic actions, the use of alkaliphilic bacteria for sealing cracks, the development of polymeric microcapsules enveloping healing agents, the use of shape memory polymers for restraining and healing of cracks and the use of flow networks to deliver healing agents in damaged regions.
Besides concrete, other construction materials such as bituminous composites and steel have gradually started gaining interest with respect to self-healing. Some self-healing strategies in this case are common to concrete, for example the use of microcapsules, but other are unique to bitumen and metals, such as heat treatment. Nonetheless, to this day the majority of published data concerns cement-based composites.
Although a lot of work has been published so far many challenges and research questions are still open. For example, almost all of the published works consider self-healing under static conditions and it is not yet clear how dynamic conditions can affect the development and the evolution of healing processes in construction materials. More information is needed on the actual efficiency of self-healing mechanisms, especially under real exposure conditions. Another issue is the repeatability of healing as well as to what extent we can engineer mechanisms that will function preventively to the upcoming damage rather than actively to repair it.
This Research Topic is intended to publish contributions into all aspects of self-healing in the whole spectrum of construction materials. The scope of the topic is to provide a platform for exchanging ideas, disseminating important advancements and share visions and concepts in the fast evolving field of self-healing construction materials. Therefore, we welcome self-healing related submissions of research papers withn novel data (both experimental and modelling) within, and not only limited to, the following topics:
o Cement based composites
o Bitumen and asphalt concrete
o Structural steel
o Soils and soil cements
o Glass for structural applications
o Repair materials such as repair mortars
o Structural ceramics
Keywords: resilience, durability, sustainability, Self-healing materials, civil infrastructure
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.