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The ground vibrations, which are generated by trains on different tracks, have been calculated by finite-element boundary-element models. The ballasted track is modelled in detail by the finite element method. The infinite soil is modelled by the boundary element method as a homogeneous or layered half-space. The track-soil system is coupled with a simple rigid mass model of the vehicle so that the vehicle-track interaction is completely included. Transfer functions are calculated in frequency domain without and with vehicle-track interaction, the compliance of the track and the mobilities of the soil at different distances from the track. Finally, the ratios between the ground vibration amplitudes with and without mitigation measure are calculated to quantify the effectiveness of the mitigation measure.
Tracks with under sleeper pads have been investigated in a wide parameter study. The main parameters that influence the reduction of ground vibration are the stiffness of the under sleeper pad, the mass and the width of the sleeper. The softest sleeper pad yields the best reduction of the ground vibration. The influence of the sleeper mass is not as strong as the characteristic frequency is ruled by the mass of the sleeper and the mass of the wheelset as well.
The influence of other parameters has been examined. The stiffness of the rail pads, the bending stiffness of the track, the stiffness of the ballast, the sub-soil, and the soil, and the layering of the soil. All these parameters show no or only a minor influence on the mitigation effect.
As the standard isolated track, a track with an under sleeper pad of a stiffness of kS = 5 107 N/m has been chosen, which can also be expressed as a stiffness per area of kS ’’ = 7.4 107 N/m3 = 0.074 N/mm3.
The resonance frequency for this pad stiffness is observed between 32 and 40 Hz. The reduction of the ground vibration is about vi,I /vi,U = 0.2 and 0.1 at 100 Hz. The reduction can be improved by softer sleeper pads. But the compliance of the track gets higher than tolerable. A possibility to use softer sleeper pads without increasing the static compliance of the track is their combination with wide sleepers. The softer sleeper pads under wider sleepers yield the same compliance of the track and a better reduction of the ground vibration.
Determining a pore structure’s mechanical and chemical data on lime rendering exposed outdoors and including masonry in the laboratory, with regard to their behaviour on moisture transport and weathering was the objective. In search of clues for a dose-response relation - i.e. upon a connection between the emission rate of SO2 and NOx on one hand and the degree of damage to mainly plaster having a lime component on the other - it has been of interest to what extent their structural characteristics including pore space are modified and so consequently also physico-technical properties and chemical composition. For determining corresponding criteria, a widely diversified spectrum of test methods such as to obtain data concerning porosity and moisture transport, mechanical behaviour, and chemistry as well is available. A description of the manufacture of plate-shaped rendering specimens with lime putty, industrially hydrated lime and dolomitic hydrate (the last two also having a cement admixture) and also hydraulic lime as binding agents is included. First deposition velocity and absorption rate for SO2 were determined in laboratory tests on these materials in dry and moist states. After their exposure on outdoor racks at six locations in the Berlin region with differing SO2 atmospheric contents over at least 5 years, the samples of course show timedependent modifications of chemical and physical qualities which are especially reflected in the form of profiles of structure, strength and concentration, e.g. for sulphate. Local climatic differences, however, partly exert a greater influence on material than emissions. Similar investigations were performed on samples of comparable composition exposed 4 and 17 years. But the real surprise is furnished by the renderings’ behaviour depending upon orientation and upon height at a building. Since weathering behaviour and moisture Transport (absorption, storage, release) are directly interdependent, further criteria are necessary for a critical assessment of a plasters’ pore structure. Starting from sands, plasters were characterized. The structural parameters were lastly influenced by the respective contents of sand, binder and mixing water. These results and those gained from bricks naturally find their expression in masonry sections manufactured there from, and above all in their capillary and evaporative behaviours, and also when applying different test liquids. Summary and cited literature is given at the end of this report.
In Zeiten knapper Kassen wird überall nach Wegen gesucht Kosten einzusparen. Im Bauwesen geht es dabei um Kosteneinsparungen ohne Reduktion der Sicherheit und Dauerhaftigkeit des Bauwerks. Beim Bauen im Bestand können mit einer zerstörungsfreien Prüfung von Bauwerken die Weiternutzung oder die erforderlichen Umbauten optimiert werden und so Kosten eingespart werden.
Die Nutzung und Weiterverarbeitung von Sekundärstoffen kann in der Baustoffherstellung einen Beitrag zum nachhaltigen Bauen leisten. Im Rahmen des Teilprojekts B wurde die Bewertung dieser Potenziale anhand von Beispielen ausgebaut und verifiziert. Die Basis dieser Bewertungsgrundlage ist die Erfüllung der grundlegenden technischen Anforderungen (ökobilanzielle Indikatoren, vergleichende ökobilanzielle Betrachtung). Im Teilprojekt E geht es um die Freisetzung umweltrelevanter Stoffe aus zementgebundenen Baustoffen. Überprüft werden sollte die Übereinstimmung zwischen Laborergebnissen, Modellierungen und realen Grundwasserkonzentrationen. Es wurden Schlitzwände errichtet, die in den Grundwasserleiter einbinden und umweltrelevante Parameter bestimmt. Grundsätzlich hat sich selbst bei Großbaustellen nur eine geringe Beeinflussung der Grundwasserqualität durch Beton ergeben.
Abschlussbericht zum BMWi/MNPQ-Verbundprojekt VERMERK (versteckte Merkmale) - BMWi-Vorhaben 22/07
(2011)
In den Jahren von 1994 bis 2006 wurden zahlreiche Umweltprojekte zur Sanierung wertvoller historischen Glasmalereien aus dem Mittelalter und dem 19. Jahrhundert in national bedeutenden Bauensembles erfolgreich und modellhaft durchgeführt. Die dazu entwickelten Methoden und durchgeführten Arbeiten wurden auf ihre Wirksamkeit überprüft. Durch eine Erfassung der Belastungssituation im Spalt zwischen Original und Außenschutzverglasung sowie an der Innenseite des Originals lässt sich ermitteln, wie gut die Schutzwirkung gegen die Umweltlasten tatsächlich ist. Auf der Basis von Zustandsdokumentationen, die während der damaligen Restaurierung angefertigt wurden, können durch den Vergleich mit dem gegenwärtigen Zustand inzwischen eingetretene Materialveränderungen charakterisiert werden. Messungen der Staubbelastung und die Analyse ihrer Kornfraktionen und der chemischen Zusammensetzung ermöglichten eine quantitative Ermittlung der Wirkung von Feinstaub. Die Tatsache, dass jedes Originalfenster hinter einer fachgerechten Schutzverglasung vor einer direkten Belastung mit Kondenswasser bewahrt wird, hat sich auch an den evaluierten fünf Objekten bestätigt. An der allgemein positiven Wirkung dieser Konservierungsmaßnahme gibt es keinen Zweifel.
Emissions from building products can considerably impair the quality of indoor air. The AgBB scheme is employed to evaluate the emissions of volatile organic compounds (VOC) from building products. The hygienic evaluation according to the AgBB scheme requires product-specific measuring procedures.
These are available for a range of products. They have been validated in co-operation with several research and testing institutes and have been included in the criteria for awarding the Blue Angel ecolabel.
The evaluation is, however, stricter and generally has lower limits. VOC emissions and odours can cause health problems so testing using sensors is an important element in the evaluation of building products and has – for reasons of precaution – been set down in the AgBB scheme. The main goal of the project was to derive a method of evaluation using sensors and limits for awarding the Blue Angel and for the AgBB scheme. Based on the research conducted (see Chapter 5 Results and Discussion), perceived intensity and hedonics were suggested as a suitable Evaluation method. The derivation of limits for the evaluation using sensors on the 28th day was effected in the present study through the additional questioning of the test subjects on the reasonability of a sample.
For the Blue Angel, there could be different limits of perceived intensity and hedonics for each group of products. A preliminary suggestion for possible limits – for all product groups – is a perceived intensity of 7 pi (5 pi + 2 pi as confidence coefficient, Chapter 5.1.5) and -1 (0+/-0.8, rounded to -1) for the hedonic value.
For the classification of chemicals, special standardized test procedures have been developed and are used world-wide. Safe handling and use of these chemicals depend on the correct classification which
therefore must be based on the precise and correct execution of the tests and their evaluation. In this context interlaboratory tests (round robin tests, interlaboratory comparisons / intercomparisons) are a crucial element of a laboratory's quality system. Participation in interlaboratory tests is explicitly recommended by the standard ISO/IEC 17025. The present document reports on the results of the interlaboratory test 2007 on the method UN Test N.5 “Test method for substances which in contact with water emit flammable gases” [1] / EC A.12 “Flammability (contact with water)” [2] which was organized by the Center for Quality Assurance for Testing of Dangerous Goods and Hazardous Substances.
In dependence on the chemical structure and/or the physical form and state (e.g. particle size) substances or mixtures may be able to react with water (even water damp / air humidity) under normal ambient temperature conditions. Sometimes this reaction can be violent and/or with significant generation of heat. Especially if gases are evolved this reaction may become dangerous. In addition, it is important to know whether a substance emits flammable gases due to contact with water because
special precautions are necessary especially with regard to explosion protection. The methods UN Test N.5 and EC A.12 are applied to characterize chemical substances or mixtures which in contact with water emit flammable gases. To differentiate between chemicals with these properties and chemicals which are not classified as hazardous / dangerous, the substance’s gas evolution rate is determined and compared to the classification criteria(s) in the last step of the test
method. In the methods UN Test N.5 / EC A.12 no special laboratory apparatus / measuring technique to determine gas evolving flow is required. However, practical experience shows that the testing procedure for substances and mixtures which in contact with water emit flammable gases is sensitive to a number of influencing factors. Since the methods (UN N.5 / EC A.12) were developed and came into force in the early nineties a
systematic review concerning the practical application of the test method has not been carried out.
For the classification of chemicals, special standardized test procedures have been developed and are used world-wide. Safe handling and use of these chemicals depend on the correct classification which therefore must be based on the precise and correct execution of the tests and their evaluation. In this context interlaboratory tests (round robin tests, interlaboratory comparisons / intercomparisons) are a crucial element of a laboratory's quality system. Participation in interlaboratory tests is explicitly recommended by the standard ISO/IEC 17025.
The present document reports on the results of the interlaboratory test 2009/2010 on the test methods UN O.2 “Test for oxidizing liquids” [1] / EC A.21 “Oxidizing Properties (Liquids)” [2] which was organized by the Center for Quality Assurance for Testing of Dangerous Goods and Hazardous Substances.
The test methods UN O.2 and EC A.21 are applied to characterize the oxidizing properties of liquid chemical substances or mixtures. To differentiate between chemicals with hazardous / dangerous oxidizing properties and chemicals which are not classified as hazardous / dangerous, the substance’s oxidizing properties are compared to those of a standard reference substance.
Since the methods (UN O.2 / EC A.21) were developed and came into force in the early nineties a systematic review concerning the practical application of the test method has not been carried out.