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On the load bearing and fatigue behaviour of headed anchor studs with defective welds The welding of headed anchor studs (KBD) is a technically demanding process. The main difficulty for contractors is that it is not yet possible to provide non‐destructive evidence that the product is free of defects. The publication of Allgemeines Rundschreiben Straßenbau (ARS) No. 18/2019 on quality assurance when welding headed stud dowels in bridge construction has significantly tightened the requirements for headed stud dowel welding. Since a company owes a defect‐free trade at the time of handover, but the freedom from defects of headed anchor studs can currently only be proven by means of destructive testing, this creates a considerable entrepreneurial risk for the practice. Although the standards and guidelines provide information on the procedure that can be used to ensure defect‐free bolts, there is no guarantee of success. For this reason, companies had to rely on the tolerance of the acceptance criteria provided by the current standards for headed anchor studs. This article deals with faulty headed anchor stud welds as well as repair methods commonly used in practice to gain initial insights into whether the tightening within the framework of the document Allgemeines Rundschreiben Straßenbau No. 18/2019 was expedient or necessary. Initial results from the PAUT (Phased Array Ultrasound) method will also be examined to determine whether it may be possible in the future to use this method to enable non‐destructive testing of headed anchor studs. [ABSTRACT FROM AUTHOR]

Plasma‐assisted low‐pressure cold spraying and conventional cold spraying methods are used to prepare copper coatings on copper substrates. The thickness, porosity micromorphology, and mechanical and corrosion properties of the copper coating prepared by high‐pressure cold spraying and plasma‐assisted low‐pressure cold spraying are studied. The results indicated that in single‐pass deposition, the copper coating prepared by plasma‐assisted low‐pressure cold spraying has a small porosity and a thick coating under the spraying conditions with the same powder feeding rate, which has a better deposition effect. The coating grains prepared by the plasma‐assisted method undergo a recrystallization process, and the grains are refined. Plasma‐assisted low‐pressure cold spray technology can achieve a good repair effect on parts. [ABSTRACT FROM AUTHOR]

Even though the duration of usage of large household appliances is found to be an average of 13 years in Germany, the data also shows that the proportion of large household devices which are already defective within the first five years has increased in the last decade. Material, functional, psychological and economic obsolescence are defined and discussed to explain this behaviour. The aim of this study is to identify consumer behaviour and motivation in the use and disposal of two major household appliances. Furthermore, whether the devices were disposed for reasons of economy, functionality or defect will be determined. A survey of 1,972 respondents was run online and on paper to collect quantitative data about consumer behaviour regarding the disposal of household appliances such as washing machines and dishwashers throughout their lifecycle in Germany. The data gathered will help to clarify if there is a connection between the disposal principle and the device price category and age. It was found that the main reason for disposal of a device is a defect, which is mostly not repaired because of additional costs which might be higher compared to a new purchase when the lifecycle is considered. [ABSTRACT FROM AUTHOR]

In this communication, the pavement repair strategy for the Bangabadhu multipurpose bridge has been optimized. The former design of the repair strategy includes six parts of repairing cracks with epoxy adhesive, 1.4 mm thick carbon fiber reinforced polymer (carbon fiber reinforced polymer), 5 mm thick thermal insulation, 6-12 mm surface material non-shrink mortar grout, 5 mm thick waterproofing membrane, and 50 mm thick mastic asphalt. The optimized repair proposal includes five parts of repairing cracks with epoxy adhesive, 1.4 mm thick carbon fiber reinforced polymer, 4-10 mm thick epoxy resin motar grout, 5 mm thick epoxy asphalt waterproofing adhesive coat, and 50 mm thick stone mastic asphalt. In addition, the requirements for the materials selection and specific technology for the construction processes has also been provided. [ABSTRACT FROM AUTHOR]