In 1997, the Second Stichtse Bridge was built in the Netherlands using the balanced cantilever method. The use of high-strength concrete was proposed. At that time, the long-term behaviour of this material was not known, and no code provisions were applicable. Therefore, it was proposed to monitor the material behaviour and the deflections of the bridge. To evaluate the development of the
concrete compressive strength and the concrete splitting tensile strength over time, concrete cubes were cast at the same time as each of the cantilever segments, and stored inside the bridge. These samples have been tested at different points in time to study the development of the strength as a function of the elapsed time. Creep and shrinkage measurements were carried out on samples stored inside the bridge as well as in the laboratory. Temperature and moisture were monitored as well. The deflections of the bridge superstructure have been measured periodically. These measurements can be compared to predictions from finite element models. Based on the available data, it is found that the concrete compressive and splitting tensile strength remain constant. The deflections are small, and the advanced finite element models resulted in good predictions.@en

In the Netherlands, approximately 150 prestressed T-beam bridges with cast-in-between decks and mainly built in the sixties are still in service. Upon assessment, the prestressed beams often do not fulfil the design codes requirements, whereas upon inspection, they show no signs of distress. For the assessment, additional load transfer mechanisms, which could significantly enhance their structural capacity, such as compressive membrane action and transverse redistribution, are not considered. The presented research aims at quantifying these effects. Therefore, an existing simply supported multi-span T-beam bridge was tested. In total seven experiments were carried out using a single point load placed on the T-beam. Three experiments were carried out with the original structural system unchanged. In four experiments, the castin- between deck was sawn in longitudinal direction, so that the individual behaviour of the beams could be tested. In both cases two load positions, i.e. a distance of 2.25 m and 4.00 m from the support were used. By analysing both the single beam and the connected beam tests a better understanding of the load carrying capacity of this type of bridge is achieved. @en

In 1997 the Second Stichtse Bridge, a high strength concrete box girder bridge was built in the Netherlands using the balanced cantilever method. At that time, the long-term behaviour of this material (with a cube compressive strength of 75 MPa) was not known. Therefore, it was proposed to monitor the material behaviour and the deflections of the bridge for ten years, and a few properties have been monitored for twenty years. To evaluate the concrete material properties over time, concrete cubes were cast with the segments, and stored inside the bridge at the section locations. These samples have been tested periodically. Also shrinkage measurements were carried out on a concrete sample stored inside the bridge. The deflections of the bridge superstructure have been measured periodically along both edges of the bridge. Based on the available data, it is found that the concrete compressive and splitting tensile strength, as well as the shrinkage deformations, remain constant. The deflections are stabilizing as well.@en