Load testing of a floor: confirming its load-bearing capacity before changes to its use
Context
Before any change to the use of a building, it is essential to ensure that its structure is capable of supporting the expected loads.
As part of this project, CIDECO carried out an intervention on a building constructed in 1956 in order to verify the load-bearing capacity of its ground floor.
The theoretical calculations carried out beforehand identified several areas presenting the highest stress levels. On-site load tests were therefore carried out to confirm the actual behaviour of the structure and its capacity to withstand the planned service loads.
Interventions carried out
The investigations were carried out over several days according to a precise testing protocol.
To reproduce the service loads, flexible water tanks were installed on the different areas of the floor.
The tanks were gradually filled up to the defined loads while continuously monitoring the structural deflections in real time using an automated instrumentation system consisting in particular of electronic displacement gauges, flow meters and a connected data acquisition system.
Several tests were carried out to successively assess the different structural elements of the floor: primary beams, secondary beams and slabs.
Throughout the tests, visual inspections were also carried out to detect any possible defects, before a gradual unloading process and verification that the structure returned to its initial behaviour.
Methods and expertise used
This project mobilised several complementary fields of expertise:
- design and implementation of a load testing protocol;
- structural instrumentation and real-time monitoring of displacements;
- application of controlled loads using flexible water tanks;
- analysis of the observed deflections;
- comparison of the experimental results with the theoretical calculations;
- calibration of the calculation models to reflect the actual behaviour as closely as possible.
This approach makes it possible to ensure the actual behaviour of the structure under conditions representative of its future use.
Added value
The tests carried out showed very small deflections under loading and revealed no defects on the tested structural elements.
The results confirmed the good elastic behaviour of the floor as well as its capacity to withstand the planned service loads in the different areas tested.
Thanks to this instrumented testing campaign, CIDECO provided the client with an experimental validation of the calculation assumptions and reliable knowledge of the structural behaviour, making it possible to confidently consider its future operation.
