TY - GEN
A1 - Rübner, Katrin
A1 - Seher, Julia
A1 - Müller, Constanze
A1 - Müller, Anette
A1 - Liebezeit, Steffen
A1 - Schnell, Alexander
A1 - Martin, Falk
ED - Schermer, Detleff
ED - Brehm, Eric
T1 - REALight - Leichtgranulate und REA-Gips aus feinkörnigen sulfatbelasteten Bau- und Abbruchabfällen und industriellen Nebenprodukten
N2 - Die Zielstellung des Forschungsprojekts REALight ist die Entwicklung eines Verfahrens zur Herstellung von Leichtgranulaten auf der Grundlage der Ergebnisse des BMBF-Projekts „Aufbaukörnungen“ unter Erweiterung der Technologie, um Gips zurückzugewinnen und weitere mineralische Einsatzstoffe zu nutzen. In einem thermischen Verfahren werden mineralische Bau- und Abbruchabfälle über ein rohstoffliches Recycling, d. h. einen thermisch-chemischen Stoffumwandlungsprozess, zu leichten Gesteinskörnungen verarbeitet. Dabei werden im Bauschutt vorhandene Sulfate zersetzt. In einer anschließenden Rauchgaswäsche werden die Sulfate abgetrennt. Sie können als Ersatz für REA-Gips verwendet werden. Dies ist Voraussetzung für die Übertragung der Produkt- und Verfahrensidee in die Praxis und für den Nachweis der Sulfatabtrennung und -rückgewinnung aus gipshaltigem Inputmaterial. Es werden Untersuchungen zur Verbreiterung der Rohstoffbasis durch Einkopplung spezifischer mineralischer Stoffströme durchgeführt, die im Ergebnis zu einer Reduktion des Blähmittelbedarfs und einer Absenkung der Brenntemperatur führen sollen. Die Herstellung ausreichender Mengen Leichtgranulate für eine umfassende Charakterisierung nach Norm und die Praxiserprobung in bekannten Anwendungen und neuen Einsatzfeldern ist ein weiteres Projektziel.
KW - Bau- und Abbruchabfälle
KW - Bauschutt
KW - Leichtgranulat
KW - Leichte Gesteinskörnung
KW - Gipsrückgewinnung
PY - 2024
UR - https://www.ernst-und-sohn.de/mauerwerk-kalender-2024-schwerpunkte-klimagerechtes-und-nachhaltiges-bauen-befestigungen-bauen-im?tab=inhalt#rs
SN - 978-3-433-03408-8
SP - 515
EP - 518
PB - Ernst & Sohn
CY - Berlin
AN - OPUS4-60356
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schnell, Alexander
A1 - Rübner, Katrin
A1 - Seher, Julia
A1 - Müller, Constanze
A1 - Müller, Anette
A1 - Liebezeit, Steffen
A1 - Fenner, Jacob
A1 - Martin, Falk
A1 - Pniok, Nicole
T1 - Manufacturing and Application of Lightweight Aggregates from Construction and Demolition Waste
N2 - The objective of the REALight project is the development of a thermal process to produce lightweight aggregates in pilot scale and the implantation of a method to recover gypsum. Beside construction and demolition waste, various industrial by‐products are studied as raw materials. The raw materials have so far been unused or used in applications with lower quality requirements. To prove the performance of the lightweight aggregates, their technical properties are tested and their use in different applications is studied, e.g., for lightweight mortars as well as lightweight concretes.
KW - Construction and demolition waste
KW - Flue gas desulfurization gypsum
KW - Industrial by-products
KW - Infra-lightweight concrete
KW - Lightweight aggregates
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604643
DO - https://doi.org/10.1002/cite.202300211
SN - 0009-286X
VL - 96
IS - 7
SP - 969
EP - 975
PB - Wiley-VCH GmbH
CY - Weinheim
AN - OPUS4-60464
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Alexander
A1 - Trappe, Volker
A1 - Hickmann, Stefan
A1 - Ortwein, H.-P
ED - Christ, Hans-Jürgen
T1 - Investigation of the infinite life of fibre-reinforced plastics using X-ray refraction topography for the in-situ, nondestructive evaluation of micro-structural degradation processes during cyclic fatigue loading
N2 - The described investigation of carbon-fibre-reinforced plastics (CFRP) documents that damage evolution can be observed by means of X-ray refractography. Comparative investigations with synchrotron technique on CFRP and grey-scale analysis on glass fibre-reinforced-plastics (GFRP) confirm these results. Moreover it was found that the fracture mechanical properties of the matrix system influence damage nucleation and propagation in the laminate during static and fatigue loads. Single-step fatigue tests were carried out on Laminates with RIM135 and LY556 matrix systems made from non-crimped fabric (NCF) or twill weave in different fibre orientations. The damage to the LY556 laminates was characterized by laminate cracks growing rapidly over the whole specimen width, whereas the damage on the RIM135 laminates was characterized by an earlier onset of micro-cracking followed by laminate cracks. The specimens were fatigued up to 108 (very high cycle fatigue (VHCF) regime) load cycles. S-N-curves of damage initiation were drawn and boundaries were identified for endurance within the VHCF regime. A phenomenology based model focusing on matrix stress was applied to reproduce the first inter-fibre failure (IFF) under static and fatigue loads.
KW - Carbon fibre-reinforced-plastics
KW - Fatigue
KW - Damage evolution
KW - X-ray refractography
KW - Very high cycle fatigue
PY - 2018
SN - 978-3-658-24531-3
DO - https://doi.org/10.1007/978-3-658-24531-3
VL - 2018
SP - 417
EP - 439
PB - Springer Spektrum
CY - Wiesbaden
ET - 1. Auflage
AN - OPUS4-50096
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Battig, Alexander
A1 - Müller, Patrick
A1 - Bertin, Annabelle
A1 - Schartel, Bernhard
T1 - Hyperbranched Rigid Aromatic Phosphorus-Containing Flame Retardants for Epoxy Resins
N2 - A rigid aromatic phosphorus-containing hyperbranched flame retardant structure is synthesized from 10-(2,5 dihydroxyphenyl)-10H-9-oxa-
10-phosphaphenanthrene-10-oxide (DOPO-HQ), tris(4-hydroxyphenyl)phosphine oxide (THPPO), and 1,4-terephthaloyl chloride (TPC). The resulting poly-(DOPO-HQ/THPPO-terephthalate) (PDTT) is implemented as a flame retardant into an epoxy resin (EP) at a 10 wt% loading. The effects on EP are compared with those of the monomer DOPO-HQ and triphenylphosphine oxide (OPPh3) as low molar mass flame retardants. The glass transition temperature, thermal decomposition, flammability (reaction to small flame), and burning behavior of the thermosets are investigated using differential scanning calorimetry, thermogravimetric analysis, pyrolysis combustion flow calorimetry, UL 94-burning chamber testing, and cone calorimeter measurements.
Although P-contents are low at only 0.6 wt%, the study aims not at attaining V-0, but at presenting a proof of principle: Epoxy resinswith PDTT show promising fire performance, exhibiting a 25% reduction in total heat evolved (THE), a 30% reduction in peak heat release rate (PHRR) due to flame inhibition (21% reduction in effective heat of combustion (EHC)), and an increase in Tg at the same time. This study indicates that rigid aromatic hyperbranched polymeric structures offer a promising route toward multifunctional flame retardancy.
KW - Hyperbranched
KW - Aromatic
KW - Phosphorus
KW - Phosphine oxide
KW - DOPO
KW - Flame retardant
KW - Xpoxy resin
KW - Rigid
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-525910
DO - https://doi.org/10.1002/mame.202000731
SN - 1439-2054
VL - 306
IS - 4
SP - 731
PB - Wiley
AN - OPUS4-52591
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - THES
A1 - Müller, Alexander
T1 - Schädigungscharakterisierung an Faser-Kunststoff-Verbunden im Schwingversuch mittels Röntgenrefraktionstopographie unter Berücksichtigung der Matrixeigenschaften
N2 - In der vorliegenden Arbeit wurden verschiedene Epoxidharzsysteme charakterisiert. Zwei Systeme mit großen bruchmechanischen Unterschieden wurden zur Fertigung äquivalenter GFK- und CFK-Laminate mit Faserausrichtungen in 0/90° und ±45° ausgewählt. In quasi-statischen Zugversuchen und Einstufenschwingversuchen mit einem Beanspruchungsverhältnis von R= 0,1 wurden diese Laminate hinsichtlich ihres Schädigungsbeginns und ihrer Schädigungsentwicklung untersucht. Die Detektion der Schädigungen sowie die Dokumentation der Schädigungsentwicklung wurde anhand der Lichtabsorptionsanalyse an GFK-Laminaten und anhand der Röntgenrefraktionsanalyse an CFK-Laminaten umgesetzt. Auf diese Weise konnten Einflüsse der bruchmechanischen Eigenschaften der Matrix auf die Schädigungsentwicklung im Verbund aufgezeigt werden. Zudem wurden für die untersuchten Laminate die Schädigungsgrenzen bei schwingender Beanspruchung ermittelt. Anhand durchgeführter Schwingversuche an CFK-Laminaten im Very High Cycle Fatigue-(VHCF)-Lastwechselbereich bis 108 konnten Rückschlüsse vom Schädigungsverhalten im High Cycle Fatigue-(HCF)-Lastwechselbereich bis 106 auf die Dauerfestigkeit im VHCF-Bereich gezogen werden und damit VHCF-Dauerfestigkeitsgrenzen bestimmt werden. Mit dem Ziel die Ermüdung der Laminate auf die Beanspruchung der Matrix zurückzuführen, wurden die Erweiterte Inverse Laminattheorie, mikromechanikbasierte Mischungsregeln sowie eine Vergleichsspannungshypothese auf die untersuchten Laminate angewendet. Die Schädigungsgrenzen konnten damit in Form der Matrixbeanspruchung wiedergegeben werden. Die Abbildung der Ermüdung verschiedener Laminate anhand einer matrixspezifischen normierten Masterschädigungslinie ist für die behandelten CFK- und GFK-Laminate gelungen.
T3 - BAM Dissertationsreihe - 162
KW - CFK
KW - GFK
KW - Ermüdung
KW - Epoxidharz
KW - Masterschädigungslinie
KW - Röntgenrefraktion
KW - ZfP
PY - 2018
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-467833
SN - 1613-4249
VL - 162
SP - 1
EP - 204
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-46783
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Alexander
T1 - Investigation of micro defects in fiber-reinforced-plastics under cyclic loading with X-Rax-Refractography
T2 - Materials Science Engineering (MSE) 2014
CY - Darmstadt, Deutschland
DA - 2014-09-23
PY - 2014
AN - OPUS4-32714
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Alexander
T1 - Nondestructive investigation of the VHCF-endurance on cyclically loaded CFRP by X-Ray-Refractography
N2 - Carbon fiber-reinforced-plastics (CFRP) are already used under high-cycle- (HCF) and very-high-cycle-fatigue (VHCF) at relatively low loads not only in aerospace industry, but also in other growing markets like especially wind energy and increasingly also automotive industry. While the static strength of CFRP is satisfyingly predictable by means of layerwise-strenght-analysis and material data from single layers, it is more and more uncertain to predict residual strength or lifetime as the design lifetime increases. Previous studies showed that local minor cracks and inter-fiber-fracture (IFF) originate long before total failure of single layers. Reliable fatigue estimation for fiber-reinforced-plastics is not available at present. Subsequently safety-related primary structures made out of FRP are over dimensioned.
It is possible to detect the change of inner surface in a specimen by means of X-Ray-Refractography. This includes voids, intact fiber-matrix-interfaces as well as defective ones, cracks and all interfaces in plane with the X-Ray-beam. As the crack-density (including IFF) increases, the inner surface of the material correspondingly increases.
The borderline where even at high cycles no early cracks were detected was identified for selected laminates out of woven and non-crimped fabric with epoxy-matrix.
When no micro-cracks were detected up to 106 cycles, the specimens also lasted in the VHCF-regime. Furthermore for the epoxy resin LY556 in combination with carbon fiber it was distinguished that at a load minor to 50% IFF-load level, no micro cracks were detected and consequently the VHCF-endurance reached.
The integration of the set-up small-sized testing machine into the X-Ray buildup in order to achieve in-situ non-destructive detection of the crack initiation while loading the specimens (CFRP and GFRP- woven fabric and non-crimped-fabric) at the same time will increase the performance of the studies.
In earlier investigations at BAM it was shown, that the matrix has a strong influence on the micro-crack formation and finally on the total lifetime. In order to determine the influence of the matrix properties on the boarderline to infinite life, research is done on laminates while replacing the epoxy-based matrix with an equivalent one with different fracture mechanical properties.
With the evolution of early cracks and IFF monitored as well as the influence of the matrix on the crack propagation investigated we are working on an appropriate model to improve lifetime prediction in CFRP. This work is done within the priority program “infinite life” (SPP 1466) funded by Deutsche Forschungsgemeinschaft (DFG).
T2 - ECCM17
CY - München, Germany
DA - 26.06.2016
KW - X-ray
KW - CFRP
KW - FRP
KW - Micro cracks
PY - 2016
AN - OPUS4-38943
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Alexander
T1 - Nondestructive investigation of the VHCF-endurance on cyclically loaded CFRP by X-Ray-Refractography
N2 - Carbon fiber-reinforced-plastics (CFRP) are already used under high-cycle- (HCF) and very-high-cycle-fatigue (VHCF) at relatively low loads not only in aerospace industry, but also in other growing markets like especially wind energy and increasingly also automotive industry. While the static strength of CFRP is satisfyingly predictable by means of layerwise-strenght-analysis and material data from single layers, it is more and more uncertain to predict residual strength or lifetime as the design lifetime increases. Previous studies showed that local minor cracks and inter-fiber-fracture (IFF) originate long before total failure of single layers. Reliable fatigue estimation for fiber-reinforced-plastics is not available at present. Subsequently safety-related primary structures made out of FRP are over dimensioned.
It is possible to detect the change of inner surface in a specimen by means of X-Ray-Refractography. This includes voids, intact fiber-matrix-interfaces as well as defective ones, cracks and all interfaces in plane with the X-Ray-beam. As the crack-density (including IFF) increases, the inner surface of the material correspondingly increases.
The borderline where even at high cycles no early cracks were detected was identified for selected laminates out of woven and non-crimped fabric with epoxy-matrix.
When no micro-cracks were detected up to 106 cycles, the specimens also lasted in the VHCF-regime. Furthermore for the epoxy resin LY556 in combination with carbon fiber it was distinguished that at a load minor to 50% IFF-load level, no micro cracks were detected and consequently the VHCF-endurance reached.
The integration of the set-up small-sized testing machine into the X-Ray buildup in order to achieve in-situ non-destructive detection of the crack initiation while loading the specimens (CFRP and GFRP- woven fabric and non-crimped-fabric) at the same time will increase the performance of the studies.
In earlier investigations at BAM it was shown, that the matrix has a strong influence on the micro-crack formation and finally on the total lifetime. In order to determine the influence of the matrix properties on the boarderline to infinite life, research is done on laminates while replacing the epoxy-based matrix with an equivalent one with different fracture mechanical properties.
With the evolution of early cracks and IFF monitored as well as the influence of the matrix on the crack propagation investigated we are working on an appropriate model to improve lifetime prediction in CFRP. This work is done within the priority program “infinite life” (SPP 1466) funded by Deutsche Forschungsgemeinschaft (DFG).
T2 - MSE 2016
CY - Darmstadt,Germany
DA - 27.09.2016
KW - CFRP
KW - FRP
KW - X-Ray
KW - Micro cracking
PY - 2016
AN - OPUS4-38945
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Alexander
T1 - Untersuchung zur Dauerfestigkeitsgrenze in Faserkunststoffverbunden mittels Röntgenrefraktion unter Berücksichtigung des Einflusses bruchmechanischer Eigenschaften des Matrixwerkstoffes
N2 - Carbon fiber-reinforced-plastics (CFRP) are already used under high-cycle- (HCF) and very-high-cycle-fatigue (VHCF) at relatively low loads not only in aerospace industry, but also in other growing markets like especially wind energy and increasingly also automotive industry. While the static strength of CFRP is satisfyingly predictable by means of layerwise-strenght-analysis and material data from single layers, it is more and more uncertain to predict residual strength or lifetime as the design lifetime increases. Previous studies showed that local minor cracks and inter-fiber-fracture (IFF) originate long before total failure of single layers. Reliable fatigue estimation for fiber-reinforced-plastics is not available at present. Subsequently safety-related primary structures made out of FRP are over dimensioned.
It is possible to detect the change of inner surface in a specimen by means of X-Ray-Refractography. This includes voids, intact fiber-matrix-interfaces as well as defective ones, cracks and all interfaces in plane with the X-Ray-beam. As the crack-density (including IFF) increases, the inner surface of the material correspondingly increases.
The borderline where even at high cycles no early cracks were detected was identified for selected laminates out of woven and non-crimped fabric with epoxy-matrix.
When no micro-cracks were detected up to 106 cycles, the specimens also lasted in the VHCF-regime. Furthermore for the epoxy resin LY556 in combination with carbon fiber it was distinguished that at a load minor to 50% IFF-load level, no micro cracks were detected and consequently the VHCF-endurance reached.
The integration of the set-up small-sized testing machine into the X-Ray buildup in order to achieve in-situ non-destructive detection of the crack initiation while loading the specimens (CFRP and GFRP- woven fabric and non-crimped-fabric) at the same time will increase the performance of the studies.
In earlier investigations at BAM it was shown, that the matrix has a strong influence on the micro-crack formation and finally on the total lifetime. In order to determine the influence of the matrix properties on the boarderline to infinite life, research is done on laminates while replacing the epoxy-based matrix with an equivalent one with different fracture mechanical properties.
With the evolution of early cracks and IFF monitored as well as the influence of the matrix on the crack propagation investigated we are working on an appropriate model to improve lifetime prediction in CFRP. This work is done within the priority program “infinite life” (SPP 1466) funded by Deutsche Forschungsgemeinschaft (DFG).
N2 - Faser-Kunststoff Verbunde und insbesondere Kohlenstofffaserverstärkte Kunststoffe werden bereits im Bereich der hohen (HCF) und sehr hohen Lastspielzahlen (VHCF) eingesetzt. Während statische Festigkeiten für diese Materialien bereits gut vorhersagbar sind, gibt es noch keine verlässliche Methode Schwingfestigkeiten zu bestimmen.
Vergangene Studien an Faser-Kunststoff Verbunden an der BAM zeigten, dass bei Schwingbelastung Mikrorisse und Zwischenfaserrisse bereits weit vor dem finalen Versagen auftreten. Diese Schäden erhöhen die innere Oberfläche des Materials. Die Änderung der inneren Oberfläche kann mittels der Röntgenrefraktion bestimmt werden.
Damit konnte im Rahmen der aktuellen Arbeit eine Lastgrenze ermittelt werden, bei der im untersuchten Lastwechselbereich keine Mikrorisse auftreten. Unter den gegebenen Material- und Versuchsparametern kann damit von einer ermittelten Dauerfestigkeitsgrenze gesprochen werden.
T2 - Polymerwissenschaftliches Seminar des Fachgebiets Polymertechnik/-physik, Fakultät III, TU Berlin
CY - Berlin, Germany
DA - 30.11.2016
KW - X-ray
KW - CFRP
KW - Faser-Kunststoff Verbunde
PY - 2016
AN - OPUS4-38946
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Spange, S.
A1 - Seifert, Alexander
A1 - Müller, Hansjörg
A1 - Hesse, S.
A1 - Jäger, Christian
T1 - Fabrication of chromophoric xerogels by senergistic combination of nucleophilic aromatic substitution and the sol-gel process
N2 - The nucleophilic substitution of fluorine of aromatic compounds with n-aminoalkyl trialkoxysilanes and consecutive sol-gel process have been used for the fabrication of various chromophoric sol-gel materials. The displacement of the fluoro substituent of an activated aromatic molecule occurs by a primary or secondary amino group of (CH3O)3Si-(CH2)3-NHR [R- = H-; CH3-, (CH3O)3Si-(CH2)3-] in tetraalkoxysilane or alcohol as solvent and the sol-gel process can be carried in the same vessel. The HF formed is trapped by a tertiary amine and simultaneously serves as the catalyst for the sol-gel process. Various aromatic compounds have been checked for this purpose: 1-(4-fluorophenyl)-2-nitroethylene, 1-(4-fluorophenyl)-2,2-dicyanoethylene, 4-fluorobenzonitrile, 4-fluoronitrobenzene, 4,4prime-difluorobenzophenone, 4,4prime-difluorobenzil, 7,7prime-difluorodibenzylideneacetone, tetrafluoro-p-benzoquinone, and 1,5-difluoro-2,4-dinitrobenzene. Mono and disubstitution has been studied by UV/Vis- and solid state NMR spectroscopy of the xerogels.
PY - 2003
DO - https://doi.org/10.1023/A:1020789318803
SN - 0928-0707
SN - 1573-4846
VL - 26
SP - 77
EP - 81
PB - Kluwer Academic Publ.
CY - Dordrecht
AN - OPUS4-2128
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Alexander
T1 - Evaluation eines Qualifizierungsverfahrens von Harz-Faser-Verbundsystemen für Luftfahrzeuge der allgemeinen Luftfahrt
T2 - 37. Symposium für Segelflugzeugentwicklung
CY - Braunschweig, Germany
DA - 2013-11-21
PY - 2013
AN - OPUS4-29657
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Constanze
A1 - Seher, Julia
A1 - Martin, Falk
A1 - Schnell, Alexander
A1 - Rübner, Katrin
T1 - Leichtgranulate aus gemischtem Mauerwerkbruch für die Anwendung in Infraleichtbeton
T1 - Lightweight granular materials made from mixed masonry rubble for use in infra-lightweight concrete
N2 - Infraleichtbeton zeichnet sich durch eine äußerst geringe Trockenrohdichte von maximal 800 kg/m³ aus, bei gleichzeitig ausreichender Festigkeit. Daraus resultieren geringe Wärme- und Schallleitfähigkeiten. Dies ermöglicht den Einsatz als Sichtbeton in Wandelementen ohne die Notwendigkeit einer zusätzlichen Dämmschicht.
Vielversprechend erscheint der Einsatz von Leichtgranulaten in Infraleichtbeton, um seinen ökologischen Fußabdruck zu reduzieren und somit ein energieeffizientes und zugleich nachhaltiges Bauen zu ermöglichen. Die Leichtgranulate werden in einem thermo-chemischen Prozess aus gemischtem Mauerwerkbruch hergestellt. Ihre Verwendung bietet neben der Alternative zu herkömmlichen leichten Gesteinskörnungen auch die Möglichkeit, Abfallprodukte sinnvoll zu nutzen. In diesem Artikel werden die Leichtgranulate vorgestellt, ihre Anwendung in Infraleichtbeton geprüft und mit konventionellem Blähton verglichen.
N2 - Infra-lightweight concrete exhibits an extremely low dry bulk density of up to 800 kg/m³ while also providing sufficient strength, resulting in low thermal and acoustic conductivity. This allows it to be used as exposed concrete in wall panels without requiring an additional insulating layer.
Using lightweight granular materials in infra-lightweight concrete appears to be promising for reducing its environmental footprint and thus enabling energy-efficient and sustainable construction. Lightweight granules are produced from mixed masonry rubble in a thermo-chemical process. In addition to being an alternative to conventional lightweight aggregates, their use also provides the opportunity to put waste products to good use. This article reports on lightweight granules, their use in infra-lightweight concrete, and related tests in comparison to conventional expanded clay.
KW - Infraleichtbeton
KW - Leichtgranulat
KW - Mauerwerkbruch
KW - Recycling
KW - Leichte Gesteinskörnungen
PY - 2024
VL - 90
IS - 7
SP - 52
EP - 59
PB - Bauverlag
CY - Gütersloh
AN - OPUS4-60557
LA - mul
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wang, Y.
A1 - Ulbricht, Alexander
A1 - Schmidt, F.
A1 - Müller, Bernd R.
A1 - Kupsch, Andreas
A1 - Schwitalla, A.D.
T1 - Micro-CT analysis and mechanical properties of low dimensional CFR-PEEK specimens additively manufactured by material extrusion
N2 - Material extrusion of thermoplastic polymers enables the realization of complex specific designs with high performance composites. The present study aims at evaluating the mechanical properties of carbon fiberreinforced semi-crystalline thermoplastic polymer polyether ether ketone (CFR-PEEK) manufactured by material extrusion and correlating them with results obtained by micro-CT. Samples in the shape of small bars were provided by Kumovis (Munich, Germany). The determination of surface roughness and density was followed by three-point bending tests. To reveal the pore distribution as well as the fusion quality of CFR PEEK when applied with external forces, micro-CT scans were performed with an X-ray microscope before and after the mechanical test to localize the sites where the fracture is generated. The density of CFR-PEEK bars indicated that they had superior mechanical properties compared with our previous study on unfilled 3D printed PEEK (bending modulus: (5.4 ± 0.5) GPa vs. (1.05 ± 0.05) GPa to (1.48 ± 0.10) GPa; bending strength: (167 ± 11) MPa vs. (51 ± 15) to (193 ± 7) MPa). Micro-CT analyses revealed the local 3D-distribution of voids. Voids of 30 μm diameter are nearly spherical and make up the main part of the total porosity. The larger the voids, the more they deviate from a spherical shape. Significant lack-of-fusion voids are located between the deposited filaments. By growing and merging, they act as seeds for the forming fracture line in the region of the flexural specimens where the maximum local tensile stresses occurred under bending load. Our work provides a detailed analysis of printed PEEK with fiber additive and relates this with mechanical properties.
KW - CFR-PEEK
KW - Material extrusion (MEX)
KW - FFF
KW - Surface topography
KW - Bending property
KW - Micro-CT
PY - 2023
DO - https://doi.org/10.1016/j.jmbbm.2023.106085
SN - 1751-6161
VL - 146
SP - 1
EP - 9
PB - Elsevier Ltd.
AN - OPUS4-58112
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Thoralf
A1 - Beck, Matthias
A1 - Gümmer, Klaas
A1 - Tomandl, Alexander
A1 - Ebell, Gino
A1 - Angst, Ueli
T1 - Aktueller Sachstand zum Thema Korrosionsschutz im konstruktiven Holzbau
N2 - Dieser Beitrag behandelt die Anforderungen an den Korrosionsschutz metallener Verbindungsmittel im konstruktiven Holzbau. Die Wahl des Korrosionsschutzes spielt eine entscheidende Rolle für Dauerhaftigkeit und Sicherheit.
Die Korrosionsbeständigkeit wird durch holzspezifische Eigenschaften, Holzfeuchte, chemische Bestandteile und atmosphärische Bedingungen beeinflusst. Daher ist eine korrosionsschutzgerechte Werkstoffauswahl unter Berücksichtigung dieser Parameter notwendig. Historisch durch Normen wie DIN 1052 und deren Weiterentwicklungen (z. B. DIN SPEC 1052-100) geprägt, definiert der zukünftige Eurocode 5 (DIN EN 1995-1-1) Mindestanforderungen an Verbindungsmittel und deren Korrosionsschutzmaßnahmen in Bezug auf die zu erwartenden Belastungen. Trotz bestehender und kommender Normen zeigen sich in der Praxis häufig Lücken und Unsicherheiten, was den Bedarf an klaren Leitlinien und praxisnahen Lösungen unterstreicht. Fortschritte in der Beschichtungstechnologie und die Entwicklung standardisierter Prüfmethoden bieten vielversprechende Ansätze und Werkzeuge zur Verbesserung der Dauerhaftigkeit. Das Dokument betont die Bedeutung normativer Anpassungen in den kommenden Eurocodes sowie die Rolle von Forschung und Innovation, um die ökologischen und technischen Potenziale des Holzbaus besser zu nutzen und dessen Einsatz in der modernen Architektur zu fördern.
KW - Holzbau
KW - Korrosionsschutz
KW - Verbindungsmittel
KW - Eurocode 5
KW - DIN SPEC 1052-100
PY - 2025
DO - https://doi.org/10.1002/bate.70036
SN - 0932-8351
SP - 1
EP - 9
PB - Ernst & Sohn GmbH
CY - Berlin
AN - OPUS4-64405
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ulbricht, Alexander
A1 - Gollwitzer, Christian
A1 - Kupsch, Andreas
A1 - Léonard, Fabien
A1 - Müller, Bernd R.
A1 - Oesch, Tyler
A1 - Onel, Yener
A1 - Thiede, Tobias
A1 - Zscherpel, Uwe
ED - Puente León, F.
ED - Zagar, B.
T1 - Moderne Methoden der CT-gestützten Strukturanalyse
T1 - Modern techniques of CT based structure analysis
N2 - Durch den großflächigen Einsatz der Computertomographie (CT) in unterschiedlichen Industriebereichen steigen auch die Anforderungen an die quantitative Bildanalyse. Subjektive Bildwahrnehmung muss durch objektive Algorithmen ersetzt werden. In diesem Artikel stellt die Bundesanstalt für Materialforschung und -prüfung (BAM), die seit den 1980er Jahren an der Entwicklung der industriellen CT beteiligt ist, anhand ausgewählter Beispiele den aktuellen Stand ihrer Analysemethoden an verschiedenen Anwendungsbeispielen der CT vor.
N2 - The increasing use of computed tomography (CT) in various industrial sectors requires more sophisticated techniques of quantitative image analysis. Subjective image perception needs to be replaced by objective algorithms. The German Federal Institute for Materials Research and Testing (BAM) has been involved in the development of industrial CT since the 1980s. This paper summarizes the current status of quantitative 3D image analysis techniques based on selected examples.
KW - Computed tomography
KW - Computertomographie
KW - Röntgen-Refraktion
KW - X-Ray refraction
KW - Schadensanalyse
KW - Damage analysis
KW - Normung
KW - standardization
PY - 2020
DO - https://doi.org/10.1515/teme-2019-0125
SN - 0171-8096
SN - 2196-7113
VL - 87
IS - 2
SP - 81
EP - 91
PB - de Gruyter
CY - Berlin
AN - OPUS4-50337
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Rübner, Katrin
A1 - Schnell, Alexander
A1 - Müller, Anette
T1 - Comparative study of lightweight expanded aggregates made from masonry rubble or clay
N2 - Lightweight aggregates can be manufactured from masonry rubble by a thermal expanding process pursuing the idea of feedstock recycling. Throughout a series of research projects, the manufacturing process has been developed, optimized and scaled up. Various test results prove that the engineering properties of the new expanded masonry rubble aggregates are similar to those of traditional expanded clays. The aggregates show a heterogeneous and macroporous pore structure. The grains consist of cracks, cavities, large bulky pores and a solid skeleton containing small capillary pores as well as partly melted areas. But which differences and similarities exist to expanded clay aggregates, which are made from a relatively homogeneous clayey raw material? To answer this question, comparative studies on the chemical, physical, mineralogical and microstructural characteristics of expanded masonry rubble aggregates and commercial expanded clay aggregates have been conducted. In our contribution, results of particle shape and porosity measurements, mercury intrusion porosimetry and electron microscopy are presented. The microstructural characteristics are correlated with engineering properties, such as water absorption and particle strength.
KW - Lightweight aggregates
KW - Expanded aggregates
KW - Expanded granules
KW - Expanded clay
KW - Masonry rubble
KW - Chemical recycling
PY - 2023
SN - 978-2-35158-238-1
VL - 137
SP - 93
EP - 121
PB - RILEM Publications S.A.R.L.
CY - Champs-sur-Marne, France
AN - OPUS4-64752
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Silvestroni, L.
A1 - Kupsch, Andreas
A1 - Müller, Bernd R.
A1 - Ulbricht, Alexander
A1 - Wieder, Frank
A1 - Fritsch, Tobias
A1 - Sciti, D.
A1 - Bruno, Giovanni
T1 - Determination of short carbon fiber orientation in zirconium diboride ceramic matrix composites
N2 - In fiber-reinforced components, the fiber alignment and orientation have paramount influence on the thermomechanical properties of the resulting composite, for both short and continuous fiber. Here we present the case of an ultra-refractory matrix intended for extreme environment applications, ZrB2, reinforced with 20 vol% and 50 vol% short carbon fibers. In both cases, fibers tend to align perpendicular to the uniaxial pressure applied during shaping and sintering of a pellet, although the fiber tilt across the pellet thickness is difficult to determine. Moreover, for high volume fractions of reinforcement, the spatial distribution of the fibers is heterogeneous and tends to have domains of preferential orientations. We compare the information on the fiber distribution as collected by scanning electron microscopy images, X-ray computed tomography and synchrotron X-ray refraction radiography (SXRR). The three techniques prove to be complementary. Importantly, we demonstrate that SXRR yields the most statistically significant information due to the largest field of view, yet with a sensitivity down to the nanometer, and that can be successfully applied also to heavy matrix materials, such as zirconium boride.
KW - Ceramic matrix composites
KW - Synchrotron X-ray refraction radiography
KW - X-ray computed tomography
KW - Scanning electron microscopy
KW - High-temperature ceramics
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597712
DO - https://doi.org/10.1016/j.jeurceramsoc.2024.02.048
SN - 0955-2219
VL - 44
IS - 8
SP - 4853
EP - 4862
PB - Elsevier Ltd.
CY - Amsterdam
AN - OPUS4-59771
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Markötter, Henning
A1 - Müller, Bernd R.
A1 - Kupsch, Andreas
A1 - Evsevleev, Sergei
A1 - Arlt, T.
A1 - Ulbricht, Alexander
A1 - Dayani, Shahabeddin
A1 - Bruno, Giovanni
T1 - A Review of X-Ray Imaging at the BAMline (BESSY II)
N2 - The hard X-ray beamline BAMline at BESSY II (Berlin, Germany) has now been in service for 20 years. Several improvements have been implemented in this time, and this review provides an overview of the imaging methods available at the BAMline. Besides classic full-field synchrotron X-ray computed tomography (SXCT), also absorption edge CT, synchrotron X-ray refraction radiography (SXRR), and synchrotron X-ray refraction tomography (SXRCT) are used for imaging. Moreover, virtually any of those techniques are currently coupled in situ or operando with ancillary equipment such as load rigs, furnaces, or potentiostats. Each of the available techniques is explained and both the current and the potential usage are described with corresponding examples. The potential use is manifold, the examples cover organic materials, composite materials, energy-related materials, biological samples, and materials related to additive manufacturing. The article includes published examples as well as some unpublished applications.
KW - Material science
KW - Radiography
KW - Refraction
KW - Tomography
KW - X-ray imaging
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572417
DO - https://doi.org/10.1002/adem.202201034
SN - 1438-1656
SP - 1
EP - 22
PB - Wiley VHC-Verlag
AN - OPUS4-57241
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Trappe, Volker
A1 - Müller, Alexander
A1 - Hickmann, Stefan
T1 - Infinite life of CFRP evaluated non-destructively with X-ray-refraction topography in-situ mechanical loading
N2 - Carbon Fibre Reinforced Plastics (CFRP) are more and more used in modern civil aircrafts. These days the whole fuselage is made of this material (B787; A350). Due to strict certification standards the normal in-service loading gives a low stress level compared to the static and even the fatigue strength of the material. Hence CFRP are assumed to have an infinite life. To evaluate this assumption, fatigue tests on CFRP-specimens were performed up to 108 load cycles and the first inter-fibre failure was evaluated non-destructively by accompanying Xray-refraction topography. A tensile testing machine was integrated in a small angle X-ray scattering (SAXS) setup. X-ray refraction topography was performed while the CFRP samples were tensile loaded. This non-destructive technique enables the detection of micro-cracking and inter-fibre failure especially for CFRP. For Glass Fibre Reinforced Plastic (GFRP) X-ray refraction and in-situ loading has already been successfully used. The increase of inner surfaces due to inter fibre failure was measured as a function of the stress state. Fatigue tests were performed at and below the limit of inter-fibre failure strength. State of the art is to assume the failure of the samples under cyclic loading as the fatigue life. Accompanying non-destructive X-ray refraction measurements reflects the damage state and enables to trace its evolution even if the total failure of the specimens does not occur. This investigation technique is of high interest to give the engineer a design value of infinite life which is practically often reached due to knock down factors of certification standards. Finally the infinite life was found for cyclic fatigue loaded CFRP-samples even under high inter fibre transverse and shear loading investigated up to 108 load cycles.
T2 - 19th World Conference on Non-Destructive Testing
CY - Munich, Germany
DA - 13.06.2016
KW - CFRP
KW - NDT
KW - Fatigue
KW - Damage evolution
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-375015
UR - https://www.ndt.net/?id=19360
SN - 978-3-940283-78-8
VL - 2016
SP - 1
EP - 9
PB - DGZFP
CY - Berlin
AN - OPUS4-37501
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rösler, Alexander
A1 - Weidner, Steffen
A1 - Klamroth, Tillmann
A1 - Müller, Axel HE
A1 - Schlaad, Helmut
T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents
N2 - AbstractThe kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations. © 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
KW - Myrcene
KW - Anionic polymerization
KW - MALDI TOF MS
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649039
DO - https://doi.org/10.1002/pi.6772
SN - 0959-8103
SP - 1
EP - 8
PB - Wiley
AN - OPUS4-64903
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rösler, Alexander
A1 - Weidner, Steffen
A1 - Klamroth, Tillmann
A1 - Müller, Axel H. E.
A1 - Schlaad, Helmut
T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents
N2 - The kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations.
KW - MALDI-TOF MS
KW - Anionic polymerization
KW - β‐myrcene
KW - Kinetics
KW - Reaction order
KW - Activation energy
KW - Microstructure
KW - Quantum chemical calculations
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630900
DO - https://doi.org/10.1002/pi.6772
SN - 1097-0126
SP - 1
EP - 8
PB - Wiley
CY - New York, NY
AN - OPUS4-63090
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rösler, Alexander
A1 - Weidner, Steffen
A1 - Klamroth, Tillmann
A1 - Müller, Axel HE
A1 - Schlaad, Helmut
T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents
N2 - AbstractThe kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations. © 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
KW - Myrcene
KW - Anionic polymerization
KW - Reaction order
KW - Activation energy
KW - Microstructure
KW - Quantum chemical calculation
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636840
DO - https://doi.org/10.1002/pi.6772
SN - 0959-8103
SP - 1
EP - 8
PB - Wiley
AN - OPUS4-63684
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -