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Andrzej Garbacz

Other affiliations: University of Warsaw
Bio: Andrzej Garbacz is an academic researcher from Warsaw University of Technology. The author has contributed to research in topics: Compressive strength & Grain boundary. The author has an hindex of 19, co-authored 108 publications receiving 1320 citations. Previous affiliations of Andrzej Garbacz include University of Warsaw.


Papers
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TL;DR: In this article, the effect of concrete substrate surface surface preparation has been characterized by roughness measurement, description of micro-cracks in the near-to-surface layer and a pull-off cohesion test.
Abstract: One of the main processes for repairing concrete structures is patch repair. Efficiency and durability of a repaired system depends on the bond between concrete substrate and repair material. By increasing the surface roughness, the surface treatment of concrete substrate can promote mechanical interlocking that is one of the basic mechanisms of adhesion. Nevertheless, some problems may arise from “co-lateral” effects of the treatment, especially due to the development of microcracks inside the substrate. In the presented paper, the effect of concrete substrate surface preparation has been characterized by roughness measurement, description of microcracking in the near-to-surface layer and a pull-off cohesion test. After repair, pull-off bond strength has been evaluated. It is concluded that selection of a suitable surface treatment technique should be preceded by the analysis of its aggressiveness in relation to the concrete substrate strength. A procedure for bond strength estimation using multiple regression approach, based on parameters describing surface quality really generated from various roughening techniques, is then proposed.

129 citations

Journal ArticleDOI
TL;DR: In this article, the relationship between surface geometry and adhesion in repair systems is analyzed using four measurement techniques, corresponding to different levels of observation: laser, mechanical profilometry, a microscopic method and a "sand" (macroscopic) method.

114 citations

Journal ArticleDOI
TL;DR: In this paper, different surface treatments (e.g. grinding, sandblasting, shotblasting and hand-and mechanical milling) were performed and the quality of the preparation established on the basis of three main parameters: surface geometry, superficial concrete micro-cracking and adhesion.
Abstract: Existing concrete surfaces need to be roughened to a profile necessary to achieve mechanical interlocking with any repair material. In this study, different surface treatments (e.g. grinding, sandblasting, shotblasting, hand- and mechanical milling) were performed and the quality of the preparation established on the basis of three main parameters: surface geometry, superficial concrete microcracking and adhesion. Surface geometry was characterised on the basis of the measurement of surface profile—profilometry—and the analysis of statistical and amplitude parameters calculated from the waviness (lower frequencies) and the roughness (higher frequencies) profiles of the surface. Investigations were also performed to assess the quality of the superficial zone of concrete and cracks were systematically observed in relation to surface treatment where both scanning electron microscopy and light microscopy were used for analysis. Finally, a repair mortar, with or without bond coat, was applied to the concrete s...

113 citations

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TL;DR: In this article, the authors presented some chosen results of pilot research on the series of simply supported beams under flexure, reinforced with BFRP bars, compared to the reference beams with steel reinforcement.

111 citations

Journal ArticleDOI
TL;DR: In this article, the results of studies concerning polymer concretes containing fly ashes were discussed and compared against the material often applied as very fine-grained filler to concrete-like polymer composites, the raw substance - quartzite meal.

76 citations


Cited by
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Journal ArticleDOI
Abstract: This article presents an overview of the developments in stainless steels made since the 1990s. Some of the new applications that involve the use of stainless steel are also introduced. A brief introduction to the various classes of stainless steels, their precipitate phases and the status quo of their production around the globe is given first. The advances in a variety of subject areas that have been made recently will then be presented. These recent advances include (1) new findings on the various precipitate phases (the new J phase, new orientation relationships, new phase diagram for the Fe–Cr system, etc.); (2) new suggestions for the prevention/mitigation of the different problems and new methods for their detection/measurement and (3) new techniques for surface/bulk property enhancement (such as laser shot peening, grain boundary engineering and grain refinement). Recent developments in topics like phase prediction, stacking fault energy, superplasticity, metadynamic recrystallisation and the calculation of mechanical properties are introduced, too. In the end of this article, several new applications that involve the use of stainless steels are presented. Some of these are the use of austenitic stainless steels for signature authentication (magnetic recording), the utilisation of the cryogenic magnetic transition of the sigma phase for hot spot detection (the Sigmaplugs), the new Pt-enhanced radiopaque stainless steel (PERSS) coronary stents and stainless steel stents that may be used for magnetic drug targeting. Besides recent developments in conventional stainless steels, those in the high-nitrogen, low-Ni (or Ni-free) varieties are also introduced. These recent developments include new methods for attaining very high nitrogen contents, new guidelines for alloy design, the merits/demerits associated with high nitrogen contents, etc.

1,668 citations

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TL;DR: In this article, the results of research on the use of basalt fiber as reinforcement of different matrices as polymer (both thermoplastic and thermoset), metal and concrete has been presented.
Abstract: In recent years, both industrial and academic world are focussing their attention toward the development of sustainable composites, reinforced with natural fibres. In particular, among the natural fibres (i.e. animal, vegetable or mineral) that can be used as reinforcement, the basalt ones represent the most interesting for their properties. The aim of this review is to illustrate the results of research on this topical subject. In the introduction, mechanical, thermal and chemical properties of basalt fibre have been reviewed. Moreover, its main manufacturing technologies have been described. Then, the effect of using this mineral fibre as reinforcement of different matrices as polymer (both thermoplastic and thermoset), metal and concrete has been presented. Furthermore, an overview on the application of this fibre in biodegradable matrix composites and in hybrid composites has been provided. Finally, the studies on the industrial applications of basalt fibre reinforced composites have been reviewed.

795 citations

Journal ArticleDOI
TL;DR: A short review on basalt fibers used as a reinforcement material for composites and discusses them as an alternative to the use of glass fibers is presented in this paper, where an attempt to showcase the increasing trend in research publications and activity in the area of basalt fiber is also covered.
Abstract: A recent increase in the use of ecofriendly, natural fibers as reinforcement for the fabrication of lightweight, low cost polymer composites can be seen globally. One such material of interest currently being extensively used is basalt fiber, which is cost-effective and offers exceptional properties over glass fibers. The prominent advantages of these composites include high specific mechano-physico-chemical properties, biodegradability, and non-abrasive qualities to name a few. This article presents a short review on basalt fibers used as a reinforcement material for composites and discusses them as an alternative to the use of glass fibers. The paper also discusses the basics of basalt chemistry and its classification. Apart from this, an attempt to showcase the increasing trend in research publications and activity in the area of basalt fibers is also covered. Further sections discuss the improvement in mechanical, thermal and chemical resistant properties achieved for applications in specific industries.

640 citations

Journal ArticleDOI
TL;DR: In this article, the fundamental concepts of grain boundary engineering (GBE) accompanied by a critical appraisal of GBE investigations are reported, and several variants on processing route schedules to produce successfully a GBE microstructure with improved properties.

559 citations

Book
03 Apr 2013
TL;DR: In this article, the areal field parameters and areal feature parameters were compared to solar cell efficiency and the mechanical bond strength for copper on glass plating applications, using laser-structured cams and conrods.
Abstract: Introduction to surface topography.- The areal field parameters.- The areal feature parameters.- Areal filtering methods.- Areal form removal.- Areal fractal methods.- Choosing the appropriate parameter.- Characterization of individual areal features.- Multi-scale signature of surface topography.- Correlation of areal surface texture parameters to solar cell efficiency.- Characterisation of cylinder liner honing textures for production control.- Characterization of the mechanical bond strength for copper on glass plating applications.- Inspection of laser structured cams and conrods.- Road surfaces.

340 citations