Wohin mit der “Platte”? Vergangenheit,Gegenwart und Zukunft der Plattenbausubstanz im Osten Deutschlands

Where to with the Slab?: Past, Present and Future of Building Fabric made of Precast Concrete Slabs in Eastern Germany Since the fifties of the 20th century a multiplicity of accommodations in Germany, mainly in Eastern Germany, has been constructed with precast concrete slabs. This basic fabric was extensively reconstructed and modernised in the range of the “city rebuilding east” project. Today predominantly deconstruction and demolition work is being done to reduce the vacancy of accommodations. The removed construction materials and elements of the support structure and the technical equipment have to be efficiently recycled.     

Interpretation und Bewertung der Rückhalte- und Abbauvorg?nge im Abstrom der Deponie Monte Scherbelino, Frankfurt a.M.

Changes in advection and dispersion caused by retardation and degradation were studied at the landfill site “Monte Scherbelino” near Frankfurt/Main, Germany. In terms of groundwater transport, the site is considered as non-steady state and the effect of retardation and degradation on advective-dispersive transport is pivotal. By applying a technique named as “breakthrough stage analysis (BTSA)”, ratios of conservative and reactive compounds were determined along specific flow paths. Depth-specific samples were also collected during this study. Results were evaluated using reference graphs. The data set consists of long-term groundwater quality monitoring data including major ions, field parameters, heavy metals, adsorbable organic halides (AOX) and some organic trace compounds. The data set consists of hydrochemical analyses from 1968 until the construction of a cut-off trench in 1995. The BTSA tool opens additional possibilities for interpretation of groundwater plumes from landfill leachates beyond numerical transport models.     

Dachentwässerungen im Zuge geänderter normativer Anforderungen und sich ändernder klimatischer Einwirkungen – eine Planungsaufgabe?

Roof drainage in the course of changed regulation require‐ments and changed climatic influences – a planning task? The roof and building drainage is supposed to take over the flaw‐less drain of rain water. Still, the roof drainage as planned is “only” designed for a rain of medium intensity. In order to prevent damages through rain of stronger intensity the possibility of an emergency drainage will be planned. The emergency drainage and the ensured roof drainage by regular maintenance are the main drainage requirements. With the new regulation generation, planning and structural design of gutters and fall pipes are first done using basis for assessment of hydraulic nature and statistically backed up rain fall data. Nevertheless, case studies show that there is not enough attention given to the planning and design of roof and building drainage. Not uncommon, the result is water damage to the structure. An analysis of the design method shows that even in this sensitive field of building construction – in opposition to static dimensioning of components – there are usually no safeties planned. However, on the tide of the evolving climatic changes, this would make sense inter alia to prevent overloading and damages.     

Wie heiß wurde der Spannstahl der Brücke über die BAB 2 während des Brandes am 16. 07. 2004?

What was the maximum Temperature of the prestressing Steel of the Bridge over the BAB 2 during the Fire at July 16, 2004? At July 16, 2004 a bridge over the BAB 2 was damaged by fire. The practicability to repair the brigde was mainly determined by the maximum temperature of the prestressing steels during the fire. By computer simulations and chemical analysis it could be determined, that the prestressing steel has not reached a temperature of 200 °C. Plastic deformations and a permanent loss of strength could therefore be excluded with great certainty. The bridge can be repaired with relative low expense.     

Elementwände im drückenden Grundwasser. Diskrepanz zwischen Theorie und Praxis?

Double Wall Systems used in Pressing Groundwater Is there a Discrepancy between Theory and Practice? The use of double wall systems in a pressing groundwater requires a special care during design, execution and supervision. It is prerequisite for the functionality of double walls in pressing groundwater that the stringent requirements of the guideline for watertight structures (WU‐Richtlinie – German Committee for Reinforced Concrete) on the planning and execution but also on the production of the double wall panels also are realized in the precast plant. Likewise to water impermeable in‐situ concrete structures, joints and penetrations in water impermeable double wall structures are possible weak points which shall be waterproofed in a professional and durable way. However, a clear discrepancy is frequently to be seen between theory and practice. This article highlights fundamental background information, explains typical faults and gives advice for the avoidance of them.     

Werbetafel; baubewilligungs- und -anzeigefreie Maßnahmen; Nahebereich der Grundgrenzen

Eine 3,40 m hohe und 10,37 m breite Werbetafel, die von der Grundgrenze nur einen Abstand von 4,40 m aufweist, liegt im "Nahebereich dieser Grundgrenze" und ist daher baubewilligungspflichtig.     

Die Kämpf‐Stegträger der Eissporthalle Bad Reichenhall – Eine typische Holzkonstruktion der 1950er und 1960er Jahre?

A typical timber construction of the 1950's an 1960's? Kämpf‐web‐girders like the one of the ice rink in Bad Reichenhall have been used frequently, wether mostly in smaller dimensions, in the 1950's and 1960's. They are an example for the great efforts that have been made in research and practice to establish definitely the glued wood construction in timber engineering. At the latest by the end of the 1960's this aim was achieved. Nevertheless, the beginning of the glued wood construction has already been made half a century before by Otto Hetzer and others. The history of the development of the glued laminated timber is a typical example, that the so‐called process of diffusion – from innovation up to the point of general distribution and application of an innovation – especially in civil engineering often takes one or two generations.     

Sportplatz; Werbetafeln; anzeigepflichtige Bauma?nahmen; Stra?en-, Orts- und Landschaftsbild

Die Errichtung von Werbeeinrichtungen ist auf einem als "Freiland-Sondernutzung Sportplatz" gewidmeten Grundstück zul?ssig, weil Sportpl?tze typischerweise auch durch Werbeeinrichtungen gekennzeichnet sind. Beeintr?chtigt eine Werbeanlage (hier: mit 13 Tafeln in einer Gesamtl?nge von rund 102 m) aber das Landschaftsbild, muss sie untersagt werden.     

Zur Traglastoptimierung von rechteckigen Verbundstützen aus einbetonierten I‐Profilen – Lohnt sich der Einsatz von hochfestem Beton oder sind konventionelle Modifikationen genauso effizient?

Optimization of the load bearing capacity of rectangular composite columns and beam‐columns of fully encased I‐sections – is it worth to use HSC or are conventional modifications just as efficient? Composite columns and beam‐columns are efficient compression members. The question arises how far the usage of HSC can contribute to an increase of the load bearing capacity or if the restriction to f_ck ≤ 50 N/mm² acc. to current standards is sufficient. The efficiency of HSC and usual strengthening measures are shown and discussed in the following paper.