MITICA experimental testing : loading test

This report is part of the 2-year exploratory research project MITICA (MonItoring Transport Infrastructures with Connected and Automated vehicles). It presents the experimental loading testing undertaken on the Reinforced Concrete (RC) platform that represents the full-scale bridge-like structural specimen of the MITICA project. The undertaken test involves the quasi-static loading of the RC platform via application of roughly 1000 kg using a water tank at the structural mid-span. The considered load is equivalent to the weight of the moving vehicle employed in the drive-by MITICA experimental campaign. This experimental test aims to assess the structural behaviour (linear/non-linear, elastic/inelastic) under two actions: (i) the additional compressive force at the mid-span; and (ii) the thermal loading effect. A network of 14 sensors (wired and wireless) was installed onto the 9-meter-long RC platform to measure the applied force, the structural deformation at the mid-span and the supports, as well as the width of the RC cracks. Supported by numerical analysis results, it is shown that the RC platform remains in its elastic range for the additionally applied compressive load of 10.53 kN, resulting in a maximum deformation of 2.0 - 2.5 mm at the mid-span and 0.18 - 0.26 mm at the supports. A residual structural deformation of 0.4 mm is recorded at the midspan of the RC bridge after the completion of the test and the unloading of the bridge, which is attributed to the combined effect of the structural nonlinearities due to the opening of the RC cracks by 21.1 - 44.8 μm, and the influence of the environmental and structural temperature variations. It is confirmed that a linear correlation exists between the structural deformation and the environmental air temperature. The latter is related to the variations of the gradient temperature across the depth of the structural specimen (i.e., structural temperature difference between the upper and lower fibre of a structural section), resulting in a maximum structural deformation of roughly 2.0 mm (same order as the maximum deformation in the loading test) for a gradient temperature of approximately 5 𝑜𝐶