The Oxygen Pressure Surge Test (OPST) is considered to be best practice for evaluating the burn out safety of plant components and testing the compatibility of nonmetallic materials for oxygen service. Nevertheless, there are only a few laboratories worldwide performing the OPST. The Federal Institute for Materials Research and Testing (BAM) already operates oxygen pressure surge test facilities with maximum OPST pressures of 450 bar.
However, to ensure technical innovation and to enhance research and development, the decision was made to develop a new and large-scale oxygen pressure surge test facility. Due to the size and the high potential impact energies, the test facility is located outside of Berlin at BAM Test Site for Technical Safety (TTS), where large scale testing is carried out. In addition to an intended maximum OPST pressure of 750 bar, there is the possibility of testing industrial equipment with large inner volumes and diameters. The new quick opening valve constitutes the core of the system and was developed by BAM. It allows to perform tests with the standardized pressure rise times of 15 ms to 20 ms or with adjustable pressure rise times at higher or lower values. As a result, it is possible to provide customized test parameters for specific practical applications as well as research projects.
This presentation shows the status quo of this unique test facility, its performance, its technical specifications, and its new possibilities for research and development for a long term enhancement of burn out safety in oxygen application.
While there is a permanent improvement of concrete pavement mixtures and pavement construction types over the last decades, the state-of-the-art joint sealing materials and joint constructions seem to stagnate on an antiquated empirical level. This status has been reaffirmed in the latest European standard. The consequences in the motorway network due to unsatisfying capability and durabilty of joint sealing systems are unacceptable. In addition, inadequate traffic performance (noise emissions, roll-over comfort) and traffic safety losses in the joint area of concrete pavements are existing challenges. These deficits and weaknesses reflect a demand for joint sealing materials and constructions whose approval requirements take functional aspects into account. Furthermore a sufficient analysis of decisive loads and a practice-oriented method to evaluate the requirements towards performance and durability is still missed. In this contribution decisive loads to German highways are analyzed. The design of test specimen for representative functional testing of joint sealing systems is discussed. The focus is on the geometry of the test specimens and the used concrete mixture. Finally, a new approach for a function-orientated test concept that considers representative load functions is presented. The potential of this approach to validate the durability and capability of various joint sealing systems is also presented using an example.
Multiple-sample approach: reliable ranking and validated statistics of bonding and adhesive strength
(2014)
Bonding strength of adhesive-bonded joints and adhesive strength of coatings have been exclusively determined in
single-sample tests using a tensile testing machine. Necessarily, the single-sample approach was also applied to the
corresponding bonding procedure. As a consequence, reliability and reproducibility of results were restricted. By
applying the newly introduced centrifuge technology, the multiple-sample approach was realized for simultaneous
tensile testing of up to eight samples under identical conditions without any disturbing shear-force effects. In order to
introduce the multiple-sample approach into the bonding procedure, a hydraulic bonding set-up was developed which
enables identical bonding pressure also for slightly different heights of sample assemblies. Both sample approaches
were compared for various application examples: ranking of different classes of adhesives, validated statistics of
adhesive-bonded joints using one particular adhesive and effects of cleaning and plasma-treatment on the adhesive
strength of coatings. The investigated systems included glass, metals and polymer substrates, different adhesives,
metallic and dielectric coatings on polymers.
Multiple-sample approach: reliable ranking and validated statistics of bonding and adhesive strength
(2014)
Bonding strength of adhesive-bonded joints and adhesive strength of coatings have been exclusively determined in single-sample tests using a tensile testing machine. Necessarily, the single-sample approach was also applied to the corresponding bonding procedure. As a consequence, reliability and reproducibility of results were restricted. By applying the newly introduced centrifuge technology, the multiple-sample approach was realized for simultaneous tensile testing of up to eight samples under identical conditions without any disturbing shear-force effects. In order to introduce the multiple-sample approach into the bonding procedure, a hydraulic bonding set-up was developed which enables identical bonding pressure also for slightly different heights of sample assemblies. Both sample approaches were compared for various application examples: ranking of different classes of adhesives, validated statistics of adhesive-bonded joints using one particular adhesive and effects of cleaning and plasma-treatment on the adhesive strength of coatings. The investigated systems included glass, metals and polymer substrates, different adhesives, metallic and dielectric coatings on polymers.