Year-end Sale % OFF 
Abstract
Abstract In France, about 450 km of high-speed lines (HSL) are potentially subject to drain scaling problem. A HSL site affected by calcite scaling was continuously monitored for 20 months to follow the phenomenon and also to estimate the monthly calcite precipitation rate. Drain water samples were also monthly analyzed and show high calcium and sulphate concentrations. The high sulphate concentration (~6 mM) highlights the dissolution of gypsum in the drain environment. Based on the material analysis (X-ray diffraction), gypsum is present in the subballast and capping layer. Since the drain system is a multi-environments system, and based on multi-phase reactions, the study is divided into two parts: a physical one (transport of water in the system) and a chemical one (transport of the reactants in the system). The physical processes have an essential impact on the chemical precipitation processes. In the present paper, on the basis of the collected data, the physical behaviour of the experimental site (water circulation) will be presented in the first step and used in the further chemical process study. The monthly calcite precipitation rate and quantities are given as well.
Highlights
Today, more than 34,000 Km of rail lines have been laid in France, including 6% of high-speed lines (HSL)
In order to develop new maintenance technologies and strategies as well as to design new drain systems which are more resistant to calcite clogging, the study of the calcite precipitation process and the causes under the railway infrastructure context are necessary and meaningful
The corresponding water is highly calcium concentrated ([6 mmol/l) which results in the calcite precipitation inside the drain with a quantity of up to 200 kg per year
Summary
More than 34,000 Km of rail lines have been laid in France, including 6% of high-speed lines (HSL). The presence of water in the track foundation due to drainage malfunction may lead to a significant loss of its mechanical properties, which will result in rail deformation. The drain maintenance cost is heavy, for example, cleaning one kilometre drain by the high-pressure water jetting requires at least four people working during four nights. This needs the circulation interruption which leads to a cost more than 30 k€ per kilometre. In order to develop new maintenance technologies and strategies as well as to design new drain systems which are more resistant to calcite clogging, the study of the calcite precipitation process and the causes under the railway infrastructure context are necessary and meaningful
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
