Monitoring of a Swedish Integral Abutment Bridge
Abstract One of the most commonly discussed problems regarding bridges with integral abutments is the influence of longitudinal elongation of the superstructure as a result of seasonal temperature variations. A bridge built with integral abutments is often supported by a row of piles made of steel or concrete. The longitudinal elongation of the superstructure induces a displacement and a rotation at the top of the pile, which in turn may cause strains that exceeds the yield strain. Such seasonal variations may lead to low-cyclic fatigue failure in the pile. Therefore, it is of great interest to investigate the amplitude of these strains, as well as the general behaviour of the bridge. In 2005, the European R&D project, INTAB (RFSR-CT-2005-00041, “Economic and Durable Design of Bridges with Integral Abutments, 2005–2008”) was started. Within the INTAB project a composite bridge was built and monitored in Northern Sweden.
Project: Economic and Durable Design of Composite Bridges with Integral Abutments
In the design and construction of bridges, questions of sustainability, maintenance and durability are becoming more and more important for European road administrations, in addition to safety and ...
Phase characterisation of simulated high burn-up UO2 fuel
Abstract To determine the lattice constant variation with burn-up and the oxidation behaviour at high temperatures, simulated UO2-spent fuels with burn-ups up to 200 GWd tM−1 were prepared by cold pressing and sintering and characterised by X-ray diffraction analysis and thermogravimetry. The fcc-lattice parameter of the sintered samples determined at room temperature, showed a continuous decrease with the simulated burn-up. During oxidation the conversion of the simulated fuels to the (U,FP)4O9 and (U,FP)3O8-type phases was strongly delayed when the simulated burn-up exceeded 80 GWd tM−1. Also, at high burn-ups (>100 GWd tM−1), large fractions of the (U,FP)4O9-type phase remained untransformed to (U,FP)3O8 after prolonged exposure to air at 950–1000°C. This suggests a marked widening of the (U,FP)4O9-phase field when the amount of substituted uranium atoms exceeds values of about 8%.