Collaborating on self-healing concrete
Researchers from the Faculty of Civil Engineering and Geosciences (CITG) worked in collaboration with Universidad Catolica de Santiago de Guayaquil (UCSG), local communities and organisations in Ecuador, and four high school students from Wageningen in the Netherlands to implement a project using self-healing concrete in the Andean highlands of Ecuador.
The project was the culmination of research and preparation that started in 2012 when four Wageningen students won an annual competition run by Foundation Imagine with their business plan ‘Concrete Solution for a Concrete Problem’. Part of the Faculty of Life Sciences, Foundation Imagine runs an annual competition aimed at bringing together high school students who have an idea that they believe will solve a problem in a developing country and scientific researchers who have the expertise to make the idea a reality. In spite of the competition criteria that project ideas must be implemented in a developing country, the self-healing concrete project was the first submission to be implemented in the field.
Building on the students’ initial submission, researchers Guadalupe Sierra-Beltran, Henk Jonkers, Virginie Wiktor of the sustainability section of CITG worked in collaboration with researchers from (UCSG) in Ecuador to implement a project that used TU Delft’s self-healing concrete and UCSG’s expertise in natural fibres to minimise the social, environmental and financial impact of damage caused to an irrigation canal by fluctuating temperatures the Andean highlands of Ecuador. Self-healing concrete contains limestone-producing bacteria and nutrients that begin to repair small cracks as they appear. This minimises the need for costly repair operations and maintains a continuous water flow for crop irrigation.
The TU Delft team was aware that science alone would not make the project a success. With this in mind, Ecuadorian post-doctoral researcher Sierra-Beltran was asked to join the Foundation Imagine project because she not only had the scientific knowledge required but also local knowledge and contacts; two factors which Sierra-Beltran says Foundation Imagine has become more aware of the importance of as a result of this project. The collaboration with the UCSG was established because Sierra-Beltran knew of their expertise and research into the use of natural fibres to strengthen concrete.
For Sierra-Beltran the project was important on both a scientific and social level. “We had the amazing opportunity to be the first research institute to field test self-healing concrete but we also had a esponsibility to make sure that the Foundation Imagine project was actually implemented and that it benefitted the local communities as intended” said Sierra-Beltran.
TU Delft researchers believed that by using local natural fibres to strengthen concrete in addition to established local techniques for mixing concrete with only the addition of the limestone-producing bacteria into the self-healing concrete elements, the project stood a greater chance of sustained success and local ownership. “Travelling to the region to speak with local communities and ensure that they felt the project was theirs was an important step in ensuring community buy-in and support for the project” said Sierra-Beltran.
In December 2014, researchers from UCSG visited the implementation site to assess whether the self-healing concrete is addressing the issues of water loss as intended. This follow-up assessment provided data and anecdotal evidence on the sustainability of the project because local community members who were trained during the initial project implementation have since concreted an additional section of the canal.