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More information about the capability and especially about the durability of structural sealant glazing (SSG) systems are needed. To make a contribution to unanswered questions, a suitable system evaluation test is necessary. The basis for such a test is a load function, which accounts for the decisive loads SSG systems are exposed to during their working life. This paper proposes a general load function for standard SSG systems at central German locations for accelerated durability tests. Decisive loads are determined and different SSG construction types defined. The performance of these SSG systems under exposure to external loads and to a dynamic pendulum impact is investigated via finite element analyses using a hyperelastic material model. The external loads are applied separately and superimposed. Compression, tensile, and shear deformations of the sealant are determined. It is found that the sealant is subjected to normal and shear stresses simultaneously. The requirements for a representative specimen are derived. The results will be taken as basics for the development and the construction of a test facility to evaluate the durability of structural sealant glazing systems.
The operational principle for today's bridge deck surfacings is a strong and durable bond between all layers of the pavement and the concrete structure under all loads. A strong bond helps to ensure the desired safety level against water penetration. But in use there is a strong loading of the bond by crack development in the structure or pavement and its dynamical movement. To ensure the sealing function of the bridge deck surfacing over the time its waterproofing has to show a durable crack bridging ability. With it the useful life of the bridge deck surfacing is essentially determined. To characterise the influences on a durable bond strength and crack bridging ability of waterproofings special research and tests were realised in the BAM. From the test results it is possible to detect suitable waterproofing layers and differences in durability. Tensile fatigue strength and other mechanical features seems to be special suited material characteristics to describe the crack bridging behaviour of waterproofing layers.
Structural sealant glazing (SSG) is an impressive technical response to the challenges of modern structural design. The evaluation of fitness for use as well as durability is a precondition for approval of SSG-façades by building authorities because of their special safety relevance. However, the potential of the actual evaluation methodology to reproduce performance as well as durability under real use conditions is generally assessed to be limited. The concept so far is criticized as mainly single-loading and incomplete in comparison to the real use conditions. The exercised separation of the in reality interacting loading effects is assessed as insufficient and inadequate to explore performance. Consequently, the performance and capability of SSG-solutions is only fragmentarily explored. However, the most restricting argument so far is the deficit of the actual test methodology for life cycle prognosis under interacting mechanical as well as climatic loads. Because of the limited acceptance, additional structural design conditions are imposed by the authorities. Besides this restriction, there is also an increasing demand by the authorities, architects, and users for determinable working life cycles, not least under economic aspects. That is why knowledge, particularly regarding SSG-performance and durability, must be expanded. Together with partners representing all branches involved in façade engineering (engineering design, sealant producer, applicator, and cladding company) the Federal Institute for Materials Research and Testing (BAM) develops a new system test focused on the substrate–sealant–glass panel interaction. With it, a new comprehensive dynamic–mechanical evaluation methodology already introduced at the fourth Symposium in Anaheim, CA, in 2011 shall be complemented by a performance-related system test. Subject-matter of this contribution is the presentation of a new dynamic–mechanical system test method and its first experimental application on SSG-systems. We describe our approach beginning with the discussion of relevant load effects on sealant joints and with the help of a highly generalized finite element (FE) analysis. Resulting from a parameter study of various load combinations acting on different SSG-construction types, we derive a practicable deformation load function from the decisive load categories taking into account regular as well as extraordinary loads. Assumptions and procedures to quantify their parameter values (regarding the effective direction and order of deformation magnitude affecting the substrate–sealant–glass bond) are discussed. The calculated decisive sealant deformations resulting from the parameter study are validated by simplified mechanical plausibility tests. Subsequently, the transfer of the findings about the substrate–sealant–glass panel bond loading into the design and construction of an adapted system test specimen and the development of a multifunctional test facility is introduced. The multi-functional applicability of the system test device is discussed. On the basis of results during our actual operational checks, first ideas about system performance and durability under superimposed loading are presented. A validation of this new test methodology by comparison to test results of disassembled samples and in situ results is a task for separate research activities.
Fahrbahnübergänge aus Asphalt - Stand der Prüftechnik; Bewährung und Erfahrungen in Deutschland
(2005)
lm Jahre 2001 wurden einheitliche vertragliche, material- und konstruktionsspezifische Regelungen über die Ausführung, Prüfung und Abnahme von Fugenfüllungen in Verkehrsflächen eingeführt. Mit dem vorliegenden Beitrag soll die ZTV Fug-StB 01 vorgestellt und in das Technische Regelwerk zur Ausbildung von Betonfahrbahndecken im Bundesfernstraßenbau eingeordnet werden.
Die Ausführung von Abdichtungssystemen insbesondere an Ingenieurbauwerken der Verkehrsinfrastruktur greift in die unmittelbare Verfügbarkeit/Nutzbarkeit des Bauwerks ein und erfolgt deshalb i.a.R. unter höchstem Zeitdruck. Neuere materialtechnische Entwicklungen im Bereich der Flüssigkunststoff-Systeme erlauben kürzere Ausführungszeiten in einem erweiterten Einsatzspektrum. Zur Sicherstellung anforderungsgerechter Gebrauchseigenschaften des gesamten Brückenabdichtungssystems gibt die vorliegende Veröffentlichung Hinweise für die einzuhaltenden Baugrundsätze, bautechnologische Besonderheiten und Erfordernisse im Umgang mit Polymethylmethacrylat (PMMA) sowie qualitätssichernde Maßnahmen.
Die Anforderungen der modernen Infrastruktur machen schnell ausführbare Abdichtungs- und Brückenbelagssysteme für den Bundesfernstraßenbereich erforderlich. Dazu gibt es innovative Systemansätze, in denen unter Ausnutzung neuer asphalttechnologischer Erkenntnisse und Weiterentwicklungen innovative Belagsaufbauten in Ergänzung zum bestehenden technischen Regelwerk erarbeitet werden. Diese neuartigen Asphaltmaterialien mit verbesserten Asphalt-Gebrauchseigenschaften (Standfestigkeit; Tieftemperaturverhalten) werden durch Kombination mit neuartigen Flüssigkunststoffen zur Aufnahme von schnelle wiederholten Bewegungen (Rissüberbrückungseigenschaften) nochmals verbessert. Durch das optimierte Gebrauchsverhalten und die systembedingten technologischen Verbesserungen ist es bei Einhaltung besonderer materialtechnischer Anforderungen möglich, leistungsfähige Brückenabdichtungs- und Belagssysteme in deutlich schnellerer Bauzeit instandzusetzen bzw. im Neubau auszuführen. Die vorliegende Veröffentlichung verallgemeinert u. a. wissenschaftlich-technische Erkenntnisse der BAM und Erfahrungen im Umgang mit den spezialisierten Baustoffen in eine für die Straßenbaubehörden des Bundes und der Länder praktisch umsetzbare Weise.