1,721,043 research outputs found
Assessment of the residual life of corroded bridge beam
No full textRebar corrosion is one of the most common causes of deterioration of r.c. structures. The chemical attack, in fact, besides reducing the cross-section of the rebars, causes cracking in the concrete and delamination of the cover. It is therefore necessary to set up methods for the evaluation of the structural damage induced by corrosion, in order to estimate the residual load bearing capacity and then to plan the maintenance interventions. Aim of the paper is the development of general relationships between the corrosion level and the residual strength and ductility of r.c. bridge beams. On the basis of a great amount of results obtained by the authors and adopting conventional deterioration models, a procedure is proposed, suitable to estimate the life cycle of corroded structures. The proposed methodology is validated against ex-perimental results from literature and then applied to realistic cases for demonstration purposes
A simplified methodology for the evaluation of the residual life of corroded elements
No full textSteel corrosion is one of the most common causes of deterioration of reinforced concrete structures. In fact, the chemical attack causes cracking in the concrete and a number of related effects that weaken the capacity of the composite, as well as reducing the cross-section of the rebars. It is therefore extremely valuable to have methods targeted to the evaluation of the structural damage induced by corrosion for estimating the residual load bearing capacity of a structure, and then for planning the maintenance interventions. The aim of this paper is the development of a simplified methodology capable of providing conservative estimates of the residual life of corroded structures. Because of the great amount of results obtained by the authors, general relationships between the corrosion level and the residual strength and ductility of beams are derived, and their evolution is predicted using conventional deterioration models. The methodology proposed is validated using experimental results from literature
A simplified methodology for the evaluation of the residual life of corroded elements.
No full textSteel corrosion is one of the most common causes of deterioration of reinforced concrete structures. In fact, the chemical attack causes cracking in the concrete and a number of related effects that weaken the capacity of the composite, as well as reducing the cross section of the rebars. It is therefore extremely valuable to have methods targeted to the evaluation of the structural damage induced by corrosion for estimating the residual load bearing capacity of a structure, and then for planning the maintenance interventions. The aim of this paper is the development of a simplified methodology capable of providing conservative estimates of the residual life of corroded structures. Because of the great amount of results obtained by the authors, general relationships between the corrosion level and the residual strength and ductility of beams are derived, and their evolution is predicted using conventional deterioration models. The methodology proposed is validated using experimental results from literature
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
Influence of the corrosion damage scenarios on the residual life of bridge grillages
No full textAim of the paper is the analysis of the behavior of a reference r.c. bridge grillage, representative of a wide class of this structural typology, subjected to corrosion. Different damage scenarios are analyzed and the most critical situation is highlighted. The analyses are performed with numerical procedures; the corrosion effects on the structural elements are calibrated on the basis of the results of experimental test carried out by some of the authors
NONLINEAR ELECTRON-PARAMAGNETIC RESONANCE SPECTROSCOPY - DIRECT OBSERVATION OF SLOW DYNAMICS EFFECTS AT POLYMER GLASS-TRANSITION
No full textNon-linear ESR schemes can be devised with high sensitivity to slow time scales. The glass transition of a polymeric mesophase is investigated by longitudinally detected ESR (LODESR) spectroscopy. By direct linewidth measurements the orientational correlation time of paramagnetic probes is measured. The temperature dependence is found of the Williams-Landen-Ferry form
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