TY - JOUR A1 - Recknagel, Christoph A1 - Pirskawetz, Stephan T1 - Joint sealing systems for pavements - A new approach towards a performance related evaluation of capability and durability N2 - Joint sealants influence decisively the performance and service life of pavements although they account for only a small fraction of the total investment. Motivated by the damages observed and the resulting, increasing maintenance efforts, the Federal German Government recognizes the need for performance-evaluated joint sealing systems with improved capability (fitness-for-purpose) and durability. A literature study showed that an identification of the actual mechanical system behavior under realistic loads as well as a prediction regarding the durability (fatigue, climatic effects) of joint sealing systems are either completely lacking in most of the relevant evaluation methods or have only been incompletely addressed previously. Furthermore an imbalance between commonly used test methodologies and the actual development status of modern modified sealing materials exists, i.e., the current test methods are not effective in evaluating the performance of tailor-made products. In this paper, the authors suggest a methodology to overcome the present situation. In contrast to the existing, predominantly empirical evaluation and selection of joint sealing materials and systems for pavements, the new approach is defined by verified performance under relevant and superimposed loads. This new approach is expected to allow a more engineered joint design. In addition to the adaptation of performance-oriented material identification tests, a special focus was placed on the development and installation of a complex test facility for the investigation of the service capability and durability of joint sealing systems in building constructions in general. This paper presents an attempt at the realization of this approach for pavement joints with the help of our new joint sealant test equipment utilizing a specific, adapted load function, which comprises cyclic movements (slow and fast acting), as well as crucial climatic exposures. The test data and its interpretation are discussed. For example, the actual mechanical behavior of the various joint sealing systems as well as the relevant maximum loading of cohesive and adhesive bonds can be deduced and used to differentiate between systems. Furthermore, information gained allows discrimination of products within the various joint sealing systems. The test results will also enable numerical simulations, e.g., of different joint designs or materials by finite element analysis. The fatigue behavior is detected by analysis of cycle-dependent changes of the mechanical system characteristics. The evaluation methodology further allows investigation of the degradation mechanisms of specific system failures and, thus, enables service life prediction by reproducing the performance of the complete system under realistic conditions. Constructional defects and material flaws can be activated and detected by the performance-related test methodology, thus identifying possible corrections to material selection and application procedures. The potential of the proposed evaluation methodology is discussed for several thermoplastic and reactive joint sealing systems. KW - Pavement joints KW - System evaluation KW - System test method KW - Superimposed loading KW - Performance KW - Mechanical characteristics KW - Capability evaluation KW - Durability evaluation KW - Cohesive failure KW - Adhesive failure PY - 2009 U6 - https://doi.org/10.1520/JAI101961 SN - 1546-962X VL - 6 IS - 3 (Paper ID JAI101961) SP - 1 EP - 16 PB - American Society for Testing and Materials CY - West Conshohocken, Pa. AN - OPUS4-19356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Recknagel, Christoph A1 - Pirskawetz, Stephan ED - Wolf, A. T. T1 - Joint sealing systems for pavements - A new approach towards a performance related evaluation of capability and durability N2 - Joint sealants influence decisively the performance and service life of pavements although they account for only a small fraction of the total investment. Motivated by the damages observed and the resulting, increasing maintenance efforts, the Federal German Government recognizes the need for performance-evaluated joint sealing systems with improved capability (fitness-for-purpose) and durability. A literature study showed that an identification of the actual mechanical system behavior under realistic loads as well as a prediction regarding the durability (fatigue, climatic effects) of joint sealing systems are either completely lacking in most of the relevant evaluation methods or have only been incompletely addressed previously. Furthermore an imbalance between commonly used test methodologies and the actual development status of modern modified sealing materials exists, i.e., the current test methods are not effective in evaluating the performance of tailor-made products. In this paper, the authors suggest a methodology to overcome the present situation. In contrast to the existing, predominantly empirical evaluation and selection of joint sealing materials and systems for pavements, the new approach is defined by verified performance under relevant and superimposed loads. This new approach is expected to allow a more engineered joint design. In addition to the adaptation of performance-oriented material identification tests, a special focus was placed on the development and installation of a complex test facility for the investigation of the service capability and durability of joint sealing systems in building constructions in general. This paper presents an attempt at the realization of this approach for pavement joints with the help of our new joint sealant test equipment utilizing a specific, adapted load function, which comprises cyclic movements (slow and fast acting), as well as crucial climatic exposures. The test data and its interpretation are discussed. For example, the actual mechanical behavior of the various joint sealing systems as well as the relevant maximum loading of cohesive and adhesive bonds can be deduced and used to differentiate between systems. Furthermore, information gained allows discrimination of products within the various joint sealing systems. The test results will also enable numerical simulations, e.g., of different joint designs or materials by finite element analysis. The fatigue behavior is detected by analysis of cycle-dependent changes of the mechanical system characteristics. The evaluation methodology further allows investigation of the degradation mechanisms of specific system failures and, thus, enables service life prediction by reproducing the performance of the complete system under realistic conditions. Constructional defects and material flaws can be activated and detected by the performance-related test methodology, thus identifying possible corrections to material selection and application procedures. The potential of the proposed evaluation methodology is discussed for several thermoplastic and reactive joint sealing systems. KW - Pavement joints KW - System evaluation KW - System test method KW - Superimposed loading KW - Performance KW - Mechanical characteristics KW - Capability evaluation KW - Durability evaluation KW - Cohesive failure KW - Adhesive failure PY - 2010 SN - 978-0-8031-3426-3 N1 - Serientitel: ASTM Selected Technical Papers – Series title: ASTM Selected Technical Papers VL - 3 IS - STP 1514 SP - 15 EP - 37 CY - West Conshohocken, PA, USA AN - OPUS4-21933 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Recknagel, Christoph A1 - Kaatz, Rico ED - Carbary, L.D. ED - Wolf, A. T. T1 - Exploration and evaluation of the performance and durability of SSG systems by dynamic-mechanical system testing N2 - 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. KW - Sealants KW - Structural glazing KW - Performance-oriented test procedure KW - Dynamic–mechanical system test method KW - Superimposed loading KW - Performance evaluation KW - Durability evaluation KW - Performance testing KW - System evaluation KW - Structural sealants PY - 2015 SN - 978-0-8031-7611-9 U6 - https://doi.org/10.1520/STP158320140064 SN - 2154-6673 N1 - Serientitel: ASTM Selected Technical Papers – Series title: ASTM Selected Technical Papers VL - 5 IS - STP 1583 SP - 235 EP - 264 PB - ASTM CY - West Conshohocken, PA, USA AN - OPUS4-33867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kaatz, Rico A1 - Recknagel, Christoph ED - Carbary, L.D. ED - Wolf, A. T. T1 - Advanced evaluation of structural sealant glazing systems by a new system test approach N2 - 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. KW - Sealants KW - Structural glazing KW - Decisive loads KW - ANSYS KW - Finite element analysis KW - Hyperelastic KW - Non-linear material KW - Grid study KW - Sealant deformation KW - Load function KW - Performance testing KW - System evaluation KW - Structural sealants KW - Durability PY - 2015 SN - 978-0-8031-7611-9 U6 - https://doi.org/10.1520/STP158320140074 SN - 2154-6673 N1 - Serientitel: ASTM Selected Technical Papers – Series title: ASTM Selected Technical Papers VL - 5 IS - STP 1583 SP - 376 EP - 402 PB - ASTM CY - West Conshohocken, PA, USA AN - OPUS4-33868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -