Long‐term material and structural behavior of high‐strength concrete cantilever bridge: Results of 20 years monitoring

Abstract

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.

Three‐dimensional nonlinear creep and shrinkage effects of a long‐span prestressed concrete box girder bridge

“…Owing to their merits in construction, maintenance, and cost, long‐span prestressed concrete (PC) box girder bridges with the balanced cantilever method are widely used around the world. However, such bridges have generally suffered excessive deflection, cracking, and other diseases during their service lives . Bazant et al collected the excessive deflection histories of 56 PC box girder bridges around the world and found that the deflection of the bridges would last for a long time; thus, it was inferred that many other bridges suffer the same issue.…”

“…Even worse, the increased deflection will further promote the expansion of existing cracks and the emergence of new cracks. The unexpected deflection and cracking have profound impacts on the serviceability and safety of PC box girder bridges, and many researchers agree that the creep and shrinkage effects of concrete are the main causes of this phenomenon …”