1,721,012 research outputs found
Bond performances of FRP Rebars Reinforced Concrete
No full textThe structural performance of reinforced concrete elements is related to the interface behavior of rebars to concrete. In the last decade several research works were carried out to investigate the bond between fiber-reinforced polymer (FRP) rebars and concrete, however some aspects need further studies in order to obtain reliable design indications. In this paper the analysis of bond was performed referring to different kinds of FRP rebars and some varying influential parameters (surface treatment, kinds of fibers, and kinds of test). Results obtained show the role of the investigated parameters on bond stress law; in particular the surface treatments involve different transfer mechanisms passing from simple chemical adhesion and friction, for sanded rebars, to a relevant contribution of mechanical interlocking for deformed rebars. The kind of test utilized influences the most significant parameters of the bond stress–slip law and in different ways depending on the kind of rebars. Finally the kind of fibers causes a variation of interface stiffness. In addition a calibration of experimental bond–slip laws was performed on the basis of available theoretical models and the results are discussed
High-temperature behavior of reduced-mass concrete containing Expanded-Polystyrene Syntherized (EPS) particles
No full textThe renewed interest for cementitious composites containing Expanded-Polystyrene Syntherized particles – EPS is mainly due to the needs of materials recycling for sustainable constructions, as EPS particles generally come from ground polystyrene waste. By partly replacing traditional aggregates with EPS particles, concrete mass is reduced as well, to the detriment – it is fair to say - of concrete mechanical performance in ordinary environmental conditions. Other properties, however, may be of some interest, like the enhanced insulation properties and the larger macro-porosity, that may improve the mechanical properties at high temperature, something that has never been investigated so far. For such reasons, research projects are in progress in Milan and Benevento on two mixes containing EPS particles and on one reference mix (fc = 25-30 MPa). In Milan the main objective is to investigate the residual mechanical properties at the reference temperatures of 20, 150, 300, 500 and 700°C, as well as the thermal diffusivity up to 700°C. On the whole, the normalized mechanical decay of EPS concretes is slightly higher but still close to that of ordinary concrete, while the thermal diffusivity is definitely lower, to the advantage of the insulating capability. The still open problem, however, is to understand whether the game (polystyrene recycling and mass reduction) is worth the candle (more cement to counterbalance the somewhat lower mechanical properties)
Effect of Test Set-Up on Bond Strength of Concrete Elements Externally Bonded with CFRP Plates
No full textThis paper deals with the comparison of the results of two experimental programs carried out by two
laboratories (the Laboratory of Structural Testing of the University of Bologna and the Laboratory of
Structural Engineering of the University of Naples Federico II) on similar specimens. The tests were
aimed at investigating the bond behaviour of six types of Externally Bonded Carbon (EBR) plates
within the activities of an international Round Robin Test organized by the fib TG 9.3. The two
laboratories carried out the bond tests according to a similar scheme, a pull-pull single shear test, but
realized according to two different experimental set-ups.
The comparisons of the experimental results are aimed at investigating the influence of the testing
procedure on the bond strength in terms of debonding load and strain distribution. To this purpose, a
3-Dimensional and a 2-Dimensional Finite Elements models have been developed for each testing
configuration. The numerical results confirm some experimental findings and show limits of the 2D
model in simulating correctly the experimental results that, by contrast, were better indentified by the
3D model
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Closure to "Experimental response and code models of GFRP RC beams in bending" by M. Pecce, G. Manfredi, and E. Cosenza
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