Anforderungen an die Wärmedämmung der Gebäudehülle: ein Vergleich zwischen EnEV 2009 und EnEV 2007

Im Hinblick auf die Anforderungen an die Dämmung der Gebäudehülle hat sich ein Wechsel der Bezugsgrößen und Abhängigkeiten von der Energieeinsparverordnung (EnEV) 2007 zur EnEV 2009 vollzogen. Deshalb ist ein direkter Vergleich der beiden Vorschriften, zumindest bei Neubauten, nicht ohne weiteres möglich. Im folgenden Artikel wird die Möglichkeit eines allgemein gültigen Vergleichs der beiden Anforderungsniveaus untersucht. Daraus lassen sich für den Planer Schlüsse im Hinblick auf die Einhaltung der Anforderungen und deren Auswirkung auf den Entwurf und die Konstruktion ziehen. Abschnitt 1 behandelt dabei den Neubau von Wohngebäuden, Abschnitt 2 den Neubau von Nichtwohngebäuden und Abschnitt 3 die Bestandsgebäude. Comparison of the heat insulation requirements for building envelopes between EnEV 2007 and EnEV 2009. The heat insulation requirements for building envelopes depending on reference values and various conditions have been changed from EnEV 2007 (German Building Energy Conservation Ordinance) to EnEV 2009. Therefore, a direct comparison of both regulations is not possible, especially for new buildings. In this article the possibility of a generally valid comparison of both requirement levels is examined. Conclusions for the design of residential buildings, commercial buildings and refirbishment of existing buildings are given.     

Planung und Ausführung des Ersatzneubaus einer U‐Bahn‐Brücke in Berlin unter hohem Zeitdruck

Design and construction of a new bridge for the Berlin underground to replace an old structure under high time pressure. This paper is about the design and construction of a new bridge for the underground in Berlin. A new structure was necessary due to insufficient stability and serviceability of the old one. The project had to be carried out under high time pressure to avoid a decommissioning of the underground traffic. As a result of this the planning and execution phases were significantly reduced. Besides, the client provided the construction firm with the structural steel to be used for the superstructure, a potential for conflict that would need to be tackled. The project will be described from the design point of view.     

Spatial and temporal variation in indicator microbe sampling is influential in beach management decisions

Fecal indicator microbes, such as enterococci, are often used to assess potential health risks caused by pathogens at recreational beaches. Microbe levels often vary based on collection time and sampling location. The primary goal of this study was to assess how spatial and temporal variations in sample collection, which are driven by environmental parameters, impact enterococci measurements and beach management decisions. A secondary goal was to assess whether enterococci levels can be predictive of the presence of Staphylococcus aureus, a skin pathogen. Over a ten-day period, hydrometeorologic data, hydrodynamic data, bather densities, enterococci levels, and S. aureus levels including methicillin-resistant S. aureus (MRSA) were measured in both water and sand. Samples were collected hourly for both water and sediment at knee-depth, and every 6 h for water at waist-depth, supratidal sand, intertidal sand, and waterline sand. Results showed that solar radiation, tides, and rainfall events were major environmental factors that impacted enterococci levels. S. aureus levels were associated with bathing load, but did not correlate with enterococci levels or any other measured parameters. The results imply that frequencies of advisories depend heavily upon sample collection policies due to spatial and temporal variation of enterococci levels in response to environmental parameters. Thus, sampling at different times of the day and at different depths can significantly impact beach management decisions. Additionally, the lack of correlation between S. aureus and enterococci suggests that use of fecal indicators may not accurately assess risk for some pathogens.     

欧洲和中国的创意城市

在过去十几年里,没有一个概念能够像“创意城市”那样对欧洲的学术论著、城市政策和战略思考等产生如此强烈的影响.很多人认为创意城市理念已经成长为城市发展的一种新范式;但在另一部分人眼里,它不过是一种不可持续的、创造性的概念热潮而已,一旦人们发现创意城市实际能带来的现实效应非常有限,它的政治吸引力就会逐渐消失.事实上,尽管创意城市的概念非常模糊和笼统,但在全球化和城市竞争日益加剧的特殊时代背景下,它仍然激励着无数规划师、政策决策者和城市开发管理人员,想方设法地通过“创意”来推进文化、经济和城市的全面发展:     

水城:城市水资源的保护与利用

该文介绍了德国把城市水域重新利用开发为新的城市空间,利用滨水空间建造的高品质文化建筑,为居住之城增添许多新型城市空间的理论和实践。     

鲁尔传统工业区的蜕变之路

鲁尔区作为世界传统工业集聚地之一,在历史上一个多世纪的时间里,曾经为德国提供了大量的煤炭和钢铁资源,被誉为德国的动力工厂.二战结束后,鲁尔区又成为德国经济快速复苏的发动机,煤炭和钢铁生产在短期内迅速恢复,为地区发展提供了动力来源,并为国家战后重建提供了所需的钢铁资源.但是在20世纪后半叶,鲁尔区却受到了技术进步和全球化发展的重大影响.     

“水城”计划：柏林城市滨水地带的复兴

城市滨水地带曾经在工业的发展中发挥过巨大的作用。进入后工业社会以来，随着经济社会形态和产业结构的变化，城市中的滨水工业生产用地以及仓储用地相继被废弃。这些已经被污染的用地尽管需要花费高昂的代价去整治，但也具有很高的商业开发价值。本文介绍了德国统一之后柏林城市滨水地带再开发的两个大型项目实例，以期为国内类似问题和项目的研究提供借鉴和参考。     

Quantifizierungen von Grundwassereintritten in städtische Abwassersysteme mittels stabiler Isotope

Infiltration of groundwater into sewer systems increases the costs for wastewater treatment plant operators. This study explores groundwater infiltration to urban sewer systems in the city of Nuremberg (Germany). Measurements of stable isotopes at the water works, storage tanks, groundwater, and the sewage network were carried out to define input end members for mass balance calculations. Only minor differences in oxygen stable isotopes (δ¹⁸O_H2O) were found between most sewer and drinking water samples which ranged around (??9.5?±?0.1) ‰. One exception was water from a water works at Genderkingen that is situated about 80 km south of Nuremberg. Here, drinking water from bank filtrate of the Lech River had more negative δ¹⁸O_H2O values of ??11.4?‰. This difference of 1.5?‰ revealed maximum possible groundwater contributions of 41?% by mass balance calculations. To obtain more accurate results, we suggest testing the use of deuterium-enriched water (D₂O) added to the sewer system.     

Mechanische Hochtemperatureigenschaften von flugaschebasierten Geopolymerbetonen

Mechanical properties of fly ash‐based geopolymer concretes at high temperature At present, concretes based on alkali‐activated binders, so‐called geopolymer concretes, are investigated intensively in the building materials industry and by the research community as environmentally friendly alternative to Portland cement‐based concretes. These inorganic binders, which are based on industrial by‐products such as fly ash and ground granulated blast furnace slag, exhibit high resistance against corrosive acids and salts, if properly designed. The mechanical properties of fly ash‐based geopolymer concretes at high temperatures are subject of systematic investigations at the Bundesanstalt für Materialforschung und ‐prüfung (BAM) to create a basis for the structural design of fire exposed concrete members based on alkali‐activated binders. The concrete specimens, produced with quartz aggregates or lightweight aggregates and heated to a maximum temperature of 750 °C, exhibited a decrease of compressive strength up to temperatures of ca. 300 °C, attributed to formation of microcracks caused by dehydration. At higher temperatures the compressive strength of the investigated geopolymer concretes recovered partly, due to sintering processes starting from ca. 500 °C. Because of this beneficial property when compared to conventional concretes, geopolymer concretes can potentially be applied in infrastructure facilities where fire resistance is critical. From the results of the thermomechanical tests stress‐strain relationships are derived that can be used for the structural design of members made from geopolymer concretes.