1,720,966 research outputs found
Rinforzo di nodi in c.a. con incamiciatura in calcestruzzo fibrorinforzato ad elevate prestazioni
No full textRinforzo di nodi trave-pilastro d’angolo con incamiciatura in calcestruzzo fibro-rinforzato ad elevate prestazioni
No full textExperimental and analytical behaviour of RC members strengthened by means of high performance jacket
No full text
A model for beam–column corner joints of existing RC frame subjected to cyclic loading
No full textBeam-to-column joints are commonly considered critic regions for RC frames subjected to earthquake actions. When designed for gravity loads only, beam-to-column corner joints strongly affect the global structural behaviour of a frame, and they can be cause of its collapse, as shown by recent earthquakes in Europe. In the paper, a component-based f.e. model for external beam-to-column joints is presented to simulate the seismic behaviour of r.c. existing structures designed without any capacity design criteria (smooth bars with hooked-end anchorages and with no transverse reinforcements in the joint). The joint deformation is modelled by means of two separate contributions, the shear deformation of the panel zone, and the rotation at the interface sections between the joint and the structural members, due to the reinforcing bars' slip within the joint core. The work focuses on the evaluation of the joint strength and stiffness, and it points out the importance of modelling the bar bond slip within the panel zone to describe the actual frame response. The component-based f.e. model is validated by experimental results of tests on beam-to-column corner joints realized according to the construction practice of the 1960s-1970s in Italy, thus confirming the effectiveness of the presented model for the assessment of existing structures
Corner Beam-Column joints seismic retrofitting with high performance fiber-reinforced concrete jacketing
No full textThe experimental results on full-scale corner beam-column joints tests are presented herein, with the aim of studying the effectiveness in strengthening existing RC existing structures of the application of a HPFRC jacket.
The specimens subassemblies have been designed with structural deficiencies typical of the Italian construction practice of the 60’s-70’s: absence of any capacity design principle, use of smooth bars, inadequate reinforcement detailing, such as total lack of stirrups in the joint panel and hook-ended anchorage.
Both unretrofitted and retrofitted specimens have been tested under simulated seismic loads.
The results underline the significant vulnerability of the joint panel region and the critical role of the slippage phenomena related to the use of smooth bars and show that, with the application of a HPFRC jacket, it is possible to increase the bearing capacity of the columns, reaching also an adequate level of ductility and strength of the beam column joints
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Corner beam-column joints retrofitting with HPFRC jacketing
No full textThe effectiveness of a new retrofitting technique, based on the application of High Performance Fiber Reinforced Concrete jacketing for seismic upgrade of RC corner beam-column joints is investigated herein. Three full-scale experimental tests on beam-column corner joint specimens subjected to seismic loads have been performed. The specimens have been designed according to the Italian construction practice of the 60’s-70’s with typical structural deficiencies, such as use of smooth bars with hooked-end anchorage and lack of stirrups in the joint panel. The tests, performed on the unretrofitted specimens, underline the high vulnerability of the joint panel zone and the critical role of smooth reinforcement bond-slip effect. Moreover, the test showed that the retrofitting proposed solution allows increasing the bearing capacity of columns and the strength of beam-column joints, whit very little visible damage, reaching also an adequate level of ductility
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