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Reuse of concrete through development of a reconnectability index

This projects aim to further the reuse of precast concrete elements by quantifying how deconnectable and reconnectable connections are between (precast) concrete elements.

Introduction
The Horizon 2020 ReCreate project is a European research project that looks into the reuse of precast concrete elements. It is a collaboration between four universities in The Netherlands, Germany, Sweden, and Finland. Each has its own country cluster in which a pilot project is achieved of an actual building that is disassembled and a new structure where the elements of this building are reused. Each country also has its industry partners, who perform these tasks, such as precast concrete manufacturers, engineering companies, deconstruction companies, and research institutes; in the Netherlands, these are VBI, IMd, Lagemaat, and TNO, respectively.

Existing indexes measure deconstructable connections; however, they do not take into account how different deconstructing techniques influence this and how this influences reconnectability afterwards. Additionally, they only consider reconnecting to the previous element(s) it was attached to, not other reclaimed or new elements. To quantify this, a reconnectability index is required.

For example, a starter-bar connection is a very common connection in precast concrete structures, commonly used in the horizontal joint between columns. Because of the use of grout, it is seen as a wet joint, which usually leads to bad scores. However, it is easy to disassemble by sawing the starter bar, and with limited additional work (and drilling of the grout tube), it is easy to recreate this connection between the elements. When trying to reconnect this to other elements than the previous elements, problems with the alignment of the connection can occur. These problems of alignment with other elements are not part of any current indexes. So, the problem of addressing easy demountability with wet joints and reconnecting elements to elements different than the previous elements needs further investigation.
 


Figure 1. Starter-bar connection [1]

Figure 2. Demountability index [2]

[1] fib (2008). fib bulletin 43: Design of structural connections for precast concrete buildings. ISBN: 9782883940833.
[2] M. van Vliet, J. van Grinsven, J. Teunizem: “Circular buildings – meetmethodiek losmaakbaarheid” https://www.dgbc.nl/publicaties/circular-buildings-een-meetmethodiek-voor-losmaakbaarheid-v20-41
[3] https://recreate-project.eu/

 

Methodology
The project will start with a literature review on connection typologies, connections in precast concrete structures, reusable and retrofit connections, deconstruction techniques, and existing indexes related to connections. Next, it will examine the missing aspects in the existing indexes and determine whether they can be adapted or extended or if a completely new index needs to be developed.

After the literature study, a plan will be created for approaching this development. This plan will entail determining the important parameters, acquiring the required additional information, weighing different parameters against each other, and more. It could also involve interviews with industry experts, visiting a deconstruction site, or more.

When the first iteration of the index is developed, this prototype should be tested by possible future users, and feedback should be received. The first series of testers could be fellow students, after which a wider audience, such as people from industry, can test the method.

Requirements
We are looking for a person who is keen to further the reuse of concrete, and who is interested in bringing this into practice with both an engineering and a designing interest.

Supervision
The project will be supervised by Simon Wijte (TU/e), Thijs Lambrechts (TU/e), and Marcel Vullings (TNO).

Interested?

The contact for this job posting is Thijs Lambrechts.