Experimental Study of the Bond of FRP Applied to Natural Stones and Masonry Prisms

2014 ◽  
Vol 624 ◽  
pp. 453-460 ◽  
Author(s):  
Matteo Panizza ◽  
Enrico Garbin ◽  
Maria Rosa Valluzzi ◽  
Claudio Modena

Compared to more traditional techniques, the application of Externally Bonded-Fibre Reinforced Polymers (EB-FRP) represents a viable alternative for the strengthening of masonry structures, also in case of Cultural Heritage buildings where strict requirements need to be met, aimed at minimizing the impact of the intervention. Since the FRP-to-masonry bond behaviour strongly affects design and effectiveness of such interventions, several investigations have been carried out in recent years to study this phenomenon, generally based on the longer experience developed for concrete substrates. Mortar joints, which are geometrical and mechanical discontinuities, distinguish and characterize masonry substrates from concrete ones, and therefore deserve a special attention as far as their role in the bond behaviour is not clarified yet. This paper, aimed at giving a contribution also from a methodological point of view, presents the main experimental results of shear tests carried out on glass composites (GFRP) applied to natural calcareous stones (pietra leccese), to lime mortar blocks and to masonry prisms made by coupling stones and lime mortar. Overall 22 shear tests were performed, keeping a bonded length of 200 mm for stones and mortar specimens while it was changed from 65 mm (corresponding to one stone and one mortar joint) to 195 mm (three stones and three mortar joints) in the case of masonry prisms. The effect of the FRP end anchorage on the test development was investigated as well, and results of the experimental tests are herein discussed in detail.

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8461
Author(s):  
Marco Dell’Isola ◽  
Giorgio Ficco ◽  
Linda Moretti ◽  
Jacek Jaworski ◽  
Paweł Kułaga ◽  
...  

Hydrogen is increasingly receiving a primary role as an energy vector in ensuring the achievement of the European decarbonization goals by 2050. In fact, Hydrogen could be produced also by electrolysis of water using renewable sources, such as photovoltaic and wind power, being able to perform the energy storage function, as well as through injection into natural gas infrastructures. However, hydrogen injection directly impacts thermodynamic properties of the gas itself, such as density, calorific value, Wobbe index, sound speed, etc. Consequently, this practice leads to changes in metrological behavior, especially in terms of volume and gas quality measurements. In this paper, the authors present an overview on the impact of hydrogen injection in natural gas measurements. In particular, the changes in thermodynamic properties of the gas mixtures with different H2 contents have been evaluated and the effects on the accuracy of volume conversion at standard conditions have been investigated both on the theoretical point of view and experimentally. To this end, the authors present and discuss the effect of H2 injection in gas networks on static ultrasonic domestic gas meters, both from a theoretical and an experimental point of view. Experimental tests demonstrated that ultrasonic gas meters are not significantly affected by H2 injection up to about 10%.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5999
Author(s):  
Michał Stopel ◽  
Artur Cichański ◽  
Nathalie Yague ◽  
Grzegorz Kończalski

The analysis aimed to assess the passive safety of supporting masts for road signs in accordance with EN 12767. Experimental tests were carried out based on the requirements of the standard for the smallest and the largest constructions within the product family. Numerical models of crash tests were prepared for whole product family using the Finite Element Method in the LS-Dyna environment. Based on the comparison of the experimental tests and the numerical calculations, the usefulness of the numerical model for estimating the actual value of the Acceleration Severity Index (ASI) and the Theoretical Head Impact Velocity (THIV) was assessed. With the use of these relationships the values of ASI and THIV for masts not tested experimentally were estimated. It was confirmed that the analyzed masts met the requirements for the passive safety of structures set out in the standard EN 12767. It was possible since as a result of the impact, the mast column detached from the base, allowing the vehicle to continue moving. The behavior of the masts was primarily influenced by the destruction of the safety connectors. The paper presents the most important elements from the point of view of designing such solutions.


2014 ◽  
Vol 624 ◽  
pp. 567-574 ◽  
Author(s):  
Marialaura Malena ◽  
Gianmarco de Felice

The composite-to-substrate interfacial stresses transfer mechanism is one of the critical issues in externally-bonded structural strengthening by means of composite fabrics. In this work, an analytical approach for modeling the debonding process of a composite on a non-homogeneous substrate is developed and applied to simulate the loss of bond of FRP on brick masonry. The analytical formulation is based on the experimental outcomes of bond shear tests, which are part of a Round Robin activity involving several laboratories. The experimental work is the follow up of a previous one [1], and comprises 12 single-lap shear tests of four kinds of unidirectional reinforcement, i.e., glass, carbon, basalt and steel, applied with epoxy resin to masonry prisms composed by five clay bricks and four mortar joints. The analytical simulations of the experimental tests rely upon a bi-linear non-homogeneous bond-slip law that was calibrated using the experimental population. Eventually, the analytical results are compared to experimental ones both, in terms of global (load to displacement curve) and local behavior (strain profile on the reinforcement for increasing load values).


2014 ◽  
Vol 624 ◽  
pp. 266-274 ◽  
Author(s):  
Matteo Panizza ◽  
Paolo Girardello ◽  
Enrico Garbin ◽  
Maria Rosa Valluzzi ◽  
Giuliana Cardani ◽  
...  

Externally Bonded (EB) composite materials are becoming a widespread solution for strengthening interventions on masonry buildings, even Cultural Heritage structures, due to several positive aspects mainly related to their high strength-to-weight ratio. In recent years, beside common epoxy-based Fibre-Reinforced Polymers (FRP), steel-based composites have been proposed: they are composed by unidirectional high-strength steel cords that can be coupled to either organic (Steel Reinforced Polymers, SRP) or inorganic (Steel Reinforced Grouts, SRG) matrices, in relation to their optimized spacing. The bond behaviour of all these EB composites has a strong influence over the effectiveness of interventions, since the detachment of reinforcements from the substrate generally represents the weaker failure mechanism. In order to improve this aspect, several anchorage devices have been proposed, being spikes, among them, one of the most suitable for masonry supports. Spikes are made of a bundle of fibres partly in the form of a bar, to be inserted and glued into a hole drilled in the substrate, and partly loose, to be spread and connected to reinforcement strips. Despite their importance also from a design point of view and considering the variety of shapes and materials, there are still few investigations in this field, being clear that both the spike-to-reinforcement and the spike-to-masonry connections need to be studied. Focused on the spike-to-masonry connection, this paper is aimed at investigating the performance of steel cord spikes applied to existing clay brick masonry, by means of overall 39 pull-out tests carried out taking into account the bonded length (equal to the hole depth), the type of embedding material and the number of steel cords forming the anchorage. The main results of this experimentation are herein presented and discussed.


1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.


Author(s):  
O. Bondar

<p><em>In this study, I have collected and summarized the functional aspects of a literary prize, contest, and rating, which indicate their affiliation with the marketing complex of the publishing house for the first time. For this purpose, I have analyzed and summarized the common concepts of the functioning of literary prizes and contests as advertising tools for publishing activity. Because the previous studies are only focused on the fact of the impact of the prize on the promotion of editions but do not explain it, these aspects have been considered and introduced by me from the book production’s point of view. I investigated that the prizes and the contests in the literary field are effective marketing tools, which meet many publisher’s needs at the same time and can be considered a non-profit form of capital. I have reviewed the works of other authors, who accept that the economic success of the book is rising if the author is a winner of the literary prize or contest. I have found out that the book prize activates the demand for the book, and the literary contest is a tool to track the reader’s reaction to a future publication. In this way, literary prizes and contests can be considered as a way of conducting a marketing dialogue with the target audience. I have focused on the information support of literary national and international prizes and contests by the media, which attracts attention to the book and forms the reader’s interest. The literary prizes and contests are also considered as a way of exploring trends and their changes, familiarization the popular genres among the target audience and fixation the current choice of modern readers. Literary prizes and contests motivate the authors to improve their literary excellence, are the source of new authors and works, and assist in increasing sales of books. However, further research is recommended.</em></p><strong><em>Key words:</em></strong><em> book prize, book rating, literary contest, literary prize, functions of the literary prizes.</em>


Author(s):  
Csilla Rákosi

Psycholinguistic research into metaphor processing is burdened with empirical problems as experiments provide diverging evidence on the impact of conventionality, familiarity and aptness, and with conceptual issues as the interpretation and operationalization of the three concepts mentioned, as well as the related predictions which can be drawn from theories of metaphor processing, are controversial in the literature. This paper uses tools of statistical meta-analysis in order to bring us closer to the solution of these problems and reveal future lines of research.


Metahumaniora ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 411
Author(s):  
Abu Bakar Ramadhan Muhamad

AbstrakHegemoni kolonialisme dalam budaya poskolonial merupakan alasan penelitian inikemudian mengkaji wacana kolonial dalam novel Max Havellar (MH) khususnya dampakditimbulkannya. Dampak dimaksud adalah posisi keberpihakan pemikiran tersirat darikarya tersebut. Hasil pembahasan menunjukkan, secara temporal maupun permanen MHmenyuarakan ketidakadilan dalam kondisi-kondisi kolonial menyangkut penindasan sangpenjajah terhadap terjajah. Hanya saja, upaya mengatasnamakan atau mewakili suarakaum terjajah terbukti mengimplikasikan ciri ideologis statis kerangka kolonialisme(orientalisme); yakni cara pandang Eropasentris, di mana “Barat” sebagai self adalah superior,dan “Timur” sebagai other adalah inferior. Dalam konteks poskolonialisme, MH dengan sifatkritisnya yang berupaya “menyuarakan” nasib pribumi terjajah, justru menampilkan stigmapenguatan kolonialitas itu sendiri secara hegemonik. Artinya, “menyuarakan” nasib pribumidimaknai sebagai keberpihankan kolonial yang kontradiktif, di mana stigma penguatankolonialitas justru lebih terasa, ujung-ujungnya melanggengkan hegemoni kolonial. Tidakmembela yang terjajah, tetapi memperhalus cara kerja mesin kolonial.AbstractThe hegemony of colonialism in the culture of postcolonial society is the reason this studythen examines the colonial discourse in the novel Max Havellar (MH) in particular the impactit brings. The impact in question is the implied position of thought in the work. The resultsof the discussion show that, temporarily or permanently, MH voiced injustice in the colonialconditions regarding the oppression of the colonist against the colonized. However, the effort toname or represent the voice of the colonized has proven to imply a static ideological characterin the framework of colonialism (orientalism); ie Eropacentric point of view, in which “West” asself is superior, and “East” as the other is the inferior. In the context of postcolonialism, MH withits critical nature that seeks to “voice” the fate of the colonized natives, actually presents thestigma of strengthening coloniality itself hegemonicly. That is, “voicing” the fate of the pribumiis interpreted as a contradictory colonial flare, where the stigma of strengthening colonialityis more pronounced, which ultimately perpetuates the hegemony of colonialism. No longerdefending the colonized, but refining the workings of the colonial machinery.


2020 ◽  
Vol 4 (2) ◽  
pp. 118-129
Author(s):  
Asti Gumartifa ◽  
◽  
Indah Windra Dwie Agustiani

Gaining English language learning effectively has been discussed all years long. Similarly, Learners have various troubles outcomes in the learning process. Creating a joyful and comfortable situation must be considered by learners. Thus, the implementation of effective learning strategies is certainly necessary for English learners. This descriptive study has two purposes: first, to introduce the classification and characterization of learning strategies such as; memory, cognitive, metacognitive, compensation, social, and affective strategies that are used by learners in the classroom and second, it provides some questionnaires item based on Strategy of Inventory for Language Learning (SILL) version 5.0 that can be used to examine the frequency of students’ learning strategies in the learning process. The summary of this study explains and discusses the researchers’ point of view on the impact of learning outcomes by learning strategies used. Finally, utilizing appropriate learning strategies are certainly beneficial for both teachers and learners to achieve the learning target effectively.


1973 ◽  
Vol 12 (4) ◽  
pp. 438-439
Author(s):  
G. M. Radhul

The book under review deals with economic integration among deve¬loping countries from the point of view of planning. The author believes that it is useful to approach economic integration from a planning point of view and to develop planning models for it, because the theory of economic integration relevant for developing countries should be directed towards the impact of integration on future investments and future production. The type of models used in the book are the multisector linear programming models and the method of analysis is essentially a comparison of two situations; one with economic integration and the other without. For each prospective partici¬pant a medium term planning model is drawn up taking account of its economic situation in some base year. The results of these single country planning models are analysed and compared to those of a similar planning model for the integration area as a whole. The consequences of the integration policy are then evaluated.


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