The lack of in-depth understanding of the seismic behavior and ductility of precast concrete structures makes it difficult to reach to ductility demand which could be exhibited during an earthquake. The limitations are mainly related to the beam-to-column connections as the main load transfer paths. Two distinct exterior beam-column connections made of normal-strength concrete are investigated experimentally. Both dry and wet type installment techniques are used in the industrial type joints while the residential type joints are wet connections. The specimens are subjected cyclic displacement reversals in order to obtain information on strength, stiffness and ductility characteristics of the connection details. The preliminary design of the joints has been updated during the tests based on the damages observed, thus a set of improved specimens have also been built and tested, and a relatively better performance is obtained expectedly. The industrial and residential types of connections showed stable load-displacement cycles with high energy dissipation up to structural drift of 2%, though a significant level of pinching and deterioration of the critical section have occurred at around 3% drift level. The tested specimens have been numerically modeled to calibrate the analytical tools, and a satisfactory approximation has been obtained between experimental and numerical results.
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Sporen uit het verleden zijn het waard bewaard te wordenvoor volgende generaties!In het onderzoeksproject Energieke Restauratie (2011-2013)van het kenniscentrum NoorderRuimte istwee jaar onderzoek gedaan naar restauratie, energieconceptenen herontwikkeling van historische gebouwen. Dit project,gefinancierd door SIA-RAAK, werd uitgevoerd in samenwerkingmet vele bedrijven en instellingen in Noord-Nederland.Energieke Restauratie verwijst naar een integrale aanpak vanbehoud en vernieuwing in historische gebouwen, met eenhoge ambitie voor energiebesparing.Een ‘Energieke Restauratie’ begint met het herkennen vanwensen en randvoorwaarden in het vooronderzoek. Zo wordtbij het ontwerp rekening gehouden met historische waarden,energie, en gebruikerswensen. Uiteraard wordt er bij derestauratie van een historisch gebouw veel aandacht besteedaan effecten op de lange termijn, bijvoorbeeld voor hetvoorkomen van schade aan historische materialen, flexibiliteitvoor (toekomstig) gebruik, energielasten en gebruikscomfort.Op 19 september 2013 vond de afsluitende internationaleconferentie ERIC2013 plaats in Groningen. Met trots bieden wiju nu het magazine Energieke Restauratie aan, waarin u korteweergaves vindt van de presentaties op ERIC2013, voornamelijkin het Engels. Bovendien zijn de volledige artikelen van veledeelnemers aan de conferentie opgenomen.Verder vindt u een beknopt overzicht van alle uitgevoerde casestudies van Energieke Restauratie.Tot slot bedanken wij iedereen die heeft bijgedragen aan detotstandkoming van dit magazine: de schrijvers van de artikelen,de vormgever en uiteraard de sponsors die het drukken van ditmagazine mogelijk hebben gemaakt.
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The ambition of a transition to a sustainable society brings forth the dual challenge to preserve historical buildings and simultaneously improve the energy performance of our built environment. While engineers claim that a dramatic reduction of energy use in the built environment is feasible, it has proven to be a difficult and twisting road.In this paper we focus on historical buildings, where difficulties of energy reduction are paramount, as such buildings provide local identity and a connection to our past. It is a EU policy objective to conserve and redesign heritage buildings like prisons, military barracks, factories, stations, and schools. Such redesign should also ensure reduction of energy use without compromising historical identity. In this paper we conceptually and empirically investigate how the two conflicting aspirations unfold. In particular we elaborate the obduracy and scripts of buildings, to clarify how they resist change and invite a specific use. We analyse the tensions between identity and energy conservation in a case study of a restoration project in Franeker. This buildinghas recently undergone a restoration, with energy efficiency as one of its goals.Scripts and networks are traced by a combination of methods, such as studyinglayout, materials and building history, and qualitative interviews with restoration architects and users. We identified three types of strategies to conserve identity and energy: design strategies; identity strategies and network strategies. Such strategies are also relevant for other efforts where conservation and innovation have to be reconciled.
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