The Experts below are selected from a list of 45 Experts worldwide ranked by ideXlab platform

Stephanos E Dritsos - One of the best experts on this subject based on the ideXlab platform.

  • concrete jacket Construction Detail effectiveness when strengthening rc columns
    Construction and Building Materials, 2008
    Co-Authors: Konstantinos G Vandoros, Stephanos E Dritsos
    Abstract:

    Abstract This paper presents an experimental investigation of the effectiveness of strengthening half height full size concrete columns by placing concrete jackets. Three alternative methods of concrete jacketing are investigated and results are compared with results from an original unstrengthened specimen and a monolithic specimen. The specimens were designed to represent typical ground floor columns of a concrete frame building. The unstrengthened column and the original columns of the strengthened specimens were designed to old 1950s Greek Codes. Poured concrete or shotcrete was used to construct the jackets of the strengthened specimens and, as performed in practice, various other Construction procedures were carried out in order to evaluate if it is worth performing the procedures when considering the practical difficulties involved. These procedures involved welding the jacket stirrup ends together, placing steel dowels across the interface between the original column and the jacket in combination with welding the jacket stirrup ends together and connecting the longitudinal reinforcement bars of the original column to the longitudinal reinforcement bars of the jacket. In order to investigate the lower limit of the effectiveness of the technique, the case of no treatment at the interface between the original column and the jacket combined with the Construction of a low strength cast in situ concrete jacket is examined. The same cross sectional dimensions and amount of steel reinforcement were used for the strengthened specimens and a control monolithic specimen. Earthquake simulation displacement controlled cyclic loading was used for the testing. The seismic performance of the tested specimens is compared in terms of strength, stiffness and hysteretic response. The effectiveness of properly constructing concrete jackets has been proved, as it was found that, under special conditions, an almost monolithic behaviour could be achieved. Even when the jacket was constructed with no treatment at the interface, a significant strength and stiffness increase was observed. It was also found that the failure mechanism and the observed crack patterns are influenced by the strengthening method. The separation of the jacket from the original column was obvious in the case when there was no treatment or other connection means performed at the contact interface between the column and the jacket. In addition, it was found that welding the jacket stirrup ends together stopped the longitudinal bars of the jacket from buckling.

Konstantinos G Vandoros - One of the best experts on this subject based on the ideXlab platform.

  • concrete jacket Construction Detail effectiveness when strengthening rc columns
    Construction and Building Materials, 2008
    Co-Authors: Konstantinos G Vandoros, Stephanos E Dritsos
    Abstract:

    Abstract This paper presents an experimental investigation of the effectiveness of strengthening half height full size concrete columns by placing concrete jackets. Three alternative methods of concrete jacketing are investigated and results are compared with results from an original unstrengthened specimen and a monolithic specimen. The specimens were designed to represent typical ground floor columns of a concrete frame building. The unstrengthened column and the original columns of the strengthened specimens were designed to old 1950s Greek Codes. Poured concrete or shotcrete was used to construct the jackets of the strengthened specimens and, as performed in practice, various other Construction procedures were carried out in order to evaluate if it is worth performing the procedures when considering the practical difficulties involved. These procedures involved welding the jacket stirrup ends together, placing steel dowels across the interface between the original column and the jacket in combination with welding the jacket stirrup ends together and connecting the longitudinal reinforcement bars of the original column to the longitudinal reinforcement bars of the jacket. In order to investigate the lower limit of the effectiveness of the technique, the case of no treatment at the interface between the original column and the jacket combined with the Construction of a low strength cast in situ concrete jacket is examined. The same cross sectional dimensions and amount of steel reinforcement were used for the strengthened specimens and a control monolithic specimen. Earthquake simulation displacement controlled cyclic loading was used for the testing. The seismic performance of the tested specimens is compared in terms of strength, stiffness and hysteretic response. The effectiveness of properly constructing concrete jackets has been proved, as it was found that, under special conditions, an almost monolithic behaviour could be achieved. Even when the jacket was constructed with no treatment at the interface, a significant strength and stiffness increase was observed. It was also found that the failure mechanism and the observed crack patterns are influenced by the strengthening method. The separation of the jacket from the original column was obvious in the case when there was no treatment or other connection means performed at the contact interface between the column and the jacket. In addition, it was found that welding the jacket stirrup ends together stopped the longitudinal bars of the jacket from buckling.

Eckhard Koch - One of the best experts on this subject based on the ideXlab platform.

  • Sustainability Assessment of Railway Bridges - Influences of High Frequency Mechanical Impact Treatment on Fillet Welds under Transversal Bending
    2014
    Co-Authors: Stephanie Breunig, Philippa Maier, Marjolaine Pfaffinger, Tim Zinke, Michael Neudeck, Martin Mensinger, U Kuhlmann, Sarah Schneider, Thomas Ummenhofer, Eckhard Koch
    Abstract:

    In Germany around a quarter of the existing railway bridges are made of steel. In the upcoming years many of these must be substituted. Not only on new stretches of tracks but also due to replacement a yearly Construction volume of about 250 railway bridges may be expected. Compared to concrete bridges it can be observed that for the majority of small and medium span steel and composite bridges are not competitive in regard of Construction costs. Further criteria considering the whole life-cycle of a bridge during the decision making process may provide more opportunities for steel and composite bridges. Thus an holistic assessment of steel and composite railway bridges is applied to three different bridge types. Therefore the durability of the bridge Constructions is enlarged by developing and optimizing the critical fatigue Details, which are determining the life time of the bridges. Within this paper the critical Construction Detail of bridge type A is picked out to show the prolonging effects of post-weld treatment.

Robert Cerný - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of thermal performance of window lintel Construction Detail
    IOP Conference Series: Materials Science and Engineering, 2018
    Co-Authors: Jan Fořt, Zbysek Pavlik, Milos Jerman, Robert Cerný
    Abstract:

    Ceramic bricks belong to the oldest and most used building material since the ancient ages. Notwithstanding, this favorable building material passed through many improvements and currently used ceramic brick is substantially improved compared to bricks from ancient production. The contemporary demands are paid especially on the mechanical resistance, high vapor permeability, outstanding thermal insulation properties, thermal accumulation function and noise insulation. On this account, the hygrothermal properties of Construction Detail composed by a contemporary lightweight hollow brick together with window lintel is investigated within this paper. Compared to laboratory methods aimed at the measurement of small samples, the semi-scale analysis represents a valuable approach for building materials testing. For this purpose, a system composed of two climatic chambers separated by the connecting tunnel with desired building Construction Detail is used. The brick block and window lintel is placed in a chamber connection tunnel, thermally insulated by mineral wool to ensure one dimensional transport and studied in sense of loading by real climatic data from Czech Republic. This valuable analysis allows long-term monitoring of the wall cross-section temperature and relative humidity profiles of particular elements in real scale. The obtained results represent valuable information for the practical application of the studied brick block in building practice. Such comparison allows optimization of building envelopes in order to improve their energy efficiency.

Chen Lu - One of the best experts on this subject based on the ideXlab platform.

  • design methods for Construction Detail of steel structure
    Science and Technology of Baotou Steel, 2011
    Co-Authors: Chen Lu
    Abstract:

    In the paper,it is illustrated systematically the design methods for Construction Detail of steel structure from the aspects such as its functions,necessities and general process of drawing,arrangement plans,general specifications of design,serial numbers of components,piece tables,Detail drawing of components and quality assurance.