In English | ISSUE 3/2024
Abstract: Testing of precast concrete elements for reuse
Reusing precast concrete elements is studied thorough four real-life pilots in Europe in the ReCreate project. Finnish pilot is an office building from 1982 located in Tampere. Load-bearing beams, columns and hollow-core slabs were reclaimed from the building. Concrete façade elements were not considered for reuse, as the age is over 40 years and requirements for insulation in new construction have been tightened in time. For reusing concrete elements, material properties are necessary, and the elements need to be designed according to existing regulations and guidelines.
The elements intended for reuse were tested before deconstruction to ensure reusability of the elements. Some of the reclaimed elements were also load tested in full scale. As a part of the project, testing requirements were studied and a decision process was developed (Figure 2). The process is based on the quality of the information gathered from the building and its elements. Sufficient testing and test methods can be minimized if the properties are known, and the property needs to be ensured. Correspondingly, if the properties are not known, more extensive and reliable testing is needed to determine the value for material properties. Sufficient testing needs to be evaluated on a case-by-case basis.
Any visual deflections or defects were not observed. Concrete cover depth and carbonation depth varied between element types, but the cover depth is sufficient for 100 years in ordinary indoor environment (exposure class XC1). The concrete cover depth is also used in determining fire resistance of the elements. The compressive strength of the elements was significantly higher than the original design value. In addition, the load test results of the hollow-core slabs were 5-47 % above the evaluated resistance.
Any barriers in properties for reusing precast concrete elements reclaimed in Finnish pilot were not found. However, the research is continuing and the quality management process for reusing concrete elements will be developed. The Reusing precast concrete for a circular economy (ReCreate) project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 958200.
