Wyniki wyszukiwania - BazTech

1

Błędy projektowe i wykonawcze płyty fundamentowej garażu podziemnego

Niedostatkiewicz Maciej, Majewski Tomasz

Przegląd Budowlany

|

2024

|

R. 95, nr 6

12--18

PL

W artykule przedstawiono opis uszkodzeń płyty fundamentowej garażu podziemnego, która została błędnie zaprojektowana, a następnie wykonana w sposób niezgodny z zasadami wiedzy technicznej. Bezpośrednio po zakończeniu realizacji płyty na jej powierzchni wystąpiły intensywne zarysowania, które miały charakter nieustabilizowany i ulegały dalszemu rozwojowi w czasie. Wykonana na płycie w ramach prac wykończeniowych posadzka również uległa zarysowaniu. W pracy przedstawiono zakres proponowanych prac naprawczych zarówno samej płyty fundamentowej, jak i uszkodzonej posadzki, tj. górnej powierzchni wykończonej zasypką utwardzoną powierzchniowo.

EN

The article presents a description of damage to the foundation slab of an underground garage, which was incorrectly designed and then constructed in a manner inconsistent with the principles of technical knowledge. Immediately after the completion of the foundation slab, intense scratches appeared on its surface, which were unstable and continued to develop over time. The floor made on the foundation slab as part of the finishing works was also scratched. The work presents proposals for the scope of repair work both on the foundation slab itself and on the damaged floor, i.e. the upper surface finished with surface-hardened backfill.

2

Elemental Composition of the Ultrafine Fraction of Road Dust in the Vicinity of Motorways and Expressways in Poland – Asphalt Versus Concrete Surfaces

Rogula-Kozłowska Wioletta, Penkała Magdalena, Bihałowicz Jan Stefan, Ogrodnik Paweł, Walczak Agata, Iwanicka Natalia

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 11

82--90

EN

Air pollution in the vicinity of roads is a complex and growing problem. In urbanised areas, there are many sources of dust emissions, but one of the main ones is road traffic. Investigating and assessing the physical and chemical properties of road dust and, more specifically, dust collected from surface courses is one way of providing an opportunity not only to identify the contribution of the emitters concerned to the formation of dust air pollution in the vicinity of roads but above all the environmental risks associated with traffic emissions. The study aimed to analyse the elemental composition of dust with a fraction <0.1 mm, collected from asphalt and concrete roads characterised by the highest technical and service parameters in Poland. The samples were analysed using a Shimadzu EDX 7000 energy-dispersive X-ray fluorescence spectrometer, then the results were statistically analysed using the t-Welch test, and the enrichment factors EF were determined. It was shown that road dust with a grain size of less than 0.1 mm collected from asphalt surface course was extremely highly enriched in Cu, Cr, Pb and S, while that from the concrete surface course was enriched in Zn and Zr, indicating a strong anthropogenic origin of these elements; exhaust gases were identified as their source. Irrespective of the type of surface course, very high dust enrichment occurs for Ca, Mn, Ni, S, Ti and Y. These elements may originate from the abrasion process of vehicle tyres. For road dust collected from both road types, the most similar EF values were found for Fe, K, Mn, Si, Sr and Ti. The source of these elements is most likely the roadside soil. It follows that the type of road surface is not the main determinant of the composition of road dust with a fraction <0.1 mm.

3

Mechanical and tribological properties of epoxy composites reinforced with food-waste fillers

Joszko K., Gzik-Zroska B., Gzik M., Wolański W., Ošlejšek M., Jureczko M., Mrówka M.

Journal of Achievements in Materials and Manufacturing Engineering

|

2023

|

Vol. 120, nr 2

49--58

EN

Purpose One of the assumptions of the zero-waste economy is to reduce the amount of industrial waste produced, process it, and recover it without burning or burying it. Citrus peels are among the food wastes that are difficult to recycle. Due to the long time of decomposition and the waxes and fats in their structure, the shells rarely end up in composters and, consequently, are not included in natural fertilisers. The assumptions fit into the research described in the article. Design/methodology/approach The authors investigated the possibility of using ground peels of citrus fruits: grapefruit, key lime, lemon and orange as fillers in composite materials in which the role of the matrix was played by epoxy resin. Composite materials with 2.5, 5 and 10% filler content were prepared. The materials were tested using the tensile, hardness, and abrasive tests using the pin-on-disc method. Findings The research was to answer whether adding citrus waste can change the physicochemical properties of composite materials based on epoxy resin and native resin. Particular attention was paid to the properties that are important from the point of view of engineering applications: mechanical properties and tribological properties. Practical implications In the face of challenges related to the growing amount of waste from the food industry, joint materials engineering tries to answer whether this waste can be used in the production of composite materials. In several publications from recent years, it has been postulated that used food industry products can be used as fillers for composite materials, as they can, on the one hand, improve specific physicochemical properties of new materials and manage food waste. Originality/value The tests proved that composite materials with grapefruit and key lime as a filler were characterized by the best tribological properties, mechanical properties, and hardness, which were unchanged or better than the epoxy resin used as a matrix.

4

Effects of spices-waste filler on the physical properties of silicone-based composites

Joszko K., Jureczko M., Ošlejšek M., Gzik-Zroska Β., Gzik M., Mrówka M.

Journal of Achievements in Materials and Manufacturing Engineering

|

2023

|

Vol. 121, nr 1

60--68

EN

Purpose The study aimed to examine the effect of using spices as fillers on the mechanical and physical properties of composite materials in which silicone plays the role of a filler. Design/methodology/approach Composite materials based on silicone were obtained by gravity casting, in which spices (garlic, paprika, pepper, and turmeric) with a mass content of 2.5, 5 and 10% of the filler. The obtained materials have been subjected to tensile test, density, hardness, and abrasion resistance. Findings The research was to answer whether adding spices can change the physicochemical properties of composite materials based on silicone and native silicone. Particular attention was paid to the properties that are important from the point of view of engineering applications: mechanical properties, tribological properties, hardness, and density. Practical implications In the face of challenges related to the growing amount of waste from the food industry, joint materials engineering tries to answer whether this waste can be used in the production of composite materials. In several publications from recent years, it has been postulated that used food industry products can be used as fillers for composite materials, as they can, on the one hand, improve specific physicochemical properties of new materials and manage food waste. Originality/value So far, few scientific articles discuss using food industry products as fillers in polymeric composites. Such articles usually focus on the use of natural plant or animal fibres. Adding spices from 2.5 to 10% by mass increases the abrasion resistance compared to silicone without adding filler. The most significant decrease in abrasion resistance was recorded for 2.5 GA and 2.5 TU. A decrease in abrasive wear by over 40% was noted here relative to neat silicone.

5

Detection of Shoreline Changes due to Abrasion and Accretion Using Landsat Imagery – A Case Study in the Coastal Areas of Supiori Regency, Indonesia

Rumahorbo Basa T., Warpur Maklon, Hamuna Baigo

Ecological Engineering & Environmental Technology

|

2023

|

Vol. 24, iss. 7

161--171

EN

Shoreline changes have become a serious problem in all coastal areas worldwide. This study aimed to detect shoreline changes and analyze the shoreline change rate caused by abrasion and accretion in the coastal area of Supiori Regency, Indonesia. Landsat 8/9 imagery was used to determine the position of the coastline in 2013 and 2023. The shoreline movement (Net Shoreline Movement) and the shoreline change rate (End Point Rate) were analyzed using the Digital Shoreline Analysis System installed on ArcMap software. The results of this study indicate that there has been abrasion and accretion where there are several very significant locations. The maximum distance of the shoreline movements due to abrasion and accretion occurred in the Supiori Selatan District as far as -67.15 and 92.86 m, respectively. The average shoreline movement caused by abrasion ranges from -11.37 to -13.59 m and from 9.75 to 15.64 m in the case of accretion. From the comparison of abrasion and accretion, only the Kepulauan Aruri District has a positive value (dominant accretion), while the other four districts have a negative value (dominant abrasion). The shoreline changes rates in the study area caused by abrasion and accretion ranged from -1.22 to -1.46 m/yr and 1.05 to 1.68 m/yr, respectively. Abrasion and accretion in the study area are predominantly caused by natural factors such as waves, currents, and river flows, as well as caused by non-natural factors mainly due to human activities. Information on shoreline changes in the study area is an important aid for stakeholders involved in coastal area management. Therefore, planning, strategies, and mitigation efforts are urgently needed to anticipate increased coastal erosion and possible negative impacts.

6

Abrasive Wear Mechanisms of S235JR, S355J2, C45, AISI 304, and Hardox 500 Steels Tested Using Garnet, Corundum and Carborundum Abrasives

Szala Mirosław, Szafran Michał, Matijošius Jonas, Drozd Kazimierz

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no 2

147--160

EN

Wear resistance is one of the main indicators of the reliability of machine parts. The selection of wear-resistant material should consider the operational environment and specific types of abrasive material. The steel abrasive wear resistance depends not only on its hardness and microstructure but also on the abrasive material's properties, such as hardness and particle morphology. This work aimed to determine abrasion wear mechanisms of a set of steels, i.e., S235, S355, C45, AISI 304 and Hardox 500, abraded by different types of grit i.e. garnet, corundum and carborundum. The abrasion tests were conducted using T-07 tribometer (rubber wheel method). Wear traces were examined with a scanning electron microscope (SEM), and a contact profilometer. SEM analysis revealed that apart from Hardox 500, ploughing and microfatigue were the dominant wear mechanisms. Microcutting was the main wear mechanism for Hardox 500 tested with carborundum (SiC). The highest mass loss was usually obtained for carborundum. The lowest wear resistance in garnet and carborundum was obtained for the S235JR and S235J2 steels and Hardox 500 tested with corundum. The effect of steel microstructure on the wear mechanism has been confirmed. AISI 304 austenitic steel abraded by carborundum grit, presented outstanding roughness parameters: Ra, Rz, RSm, Rk, Rvk and Rpk than other steels tested with carborundum. Steel hardness affects the morphology of the wear trace reducing the Ra and Rz roughness parameters. The effect of abrasive hardness and grain morphology on abraded surfaces has been stated. Contrary to fine grains of the hardest carborundum, coarse garnet grains caused high roughness parameters (Rk, Rpk and Rvk) determined in wear trace.

7

Współczesne obszary występowania mołdawitów : wnioski z eksperymentu transportowania ich przez Nysę Łużycką

Brachaniec Tomasz

Przegląd Geologiczny

|

2022

|

Vol. 70, nr 1

61--65

EN

Tektites in the sedimentary recordare subject to many geological processes such as fluvial reworking. To observe the glass behaviour during reworking, an experiment was conducted in the Lusatia Neisse river where moldavites are found. It consisted in observing the progressive abrasion of some 500 tektites over reworking distances of 100, 200, 300, and 400 km respectively. The results clearly show that moldavites could survive reworkingover a distance of several hundreds km. The decrease in weight was linear in relation to the distance travelled. Regardless of the initial shape, all tektites became rounded with a smooth surface after travelling 200 km. The experimental results suggest that European tektites were ejected from the Ries crater over distances reaching up to 600 km and were then reworked over short distances from the origin areas of the current substrewn fields.

8

The effect of shape and roughness on flotation and aggregation of quartz particles

Guven Onur

Physicochemical Problems of Mineral Processing

|

2022

|

Vol. 58, iss. 6

art. no. 154021

EN

A combination of grinding and abrasion processes was applied to control the shape and roughness of quartz particles to investigate their roles in flotation recoveries and aggregation rates at different collector concentrations. The results showed that while the roundness values (Ro) of quartz particles varied in the range of 0.56-0.58 (Ro) at 480 and 1920 sec grinding, the roughness values of particles varied between 3.12-4.02 μm at 60 and 240 min abrasion. The flotation and aggregation tests showed while the flotation recovery increased from 31.3 % to 34.2 % in reverse proportion to their roundness values at 1x10-6 M DAH concentrations, a similar increasing trend from 34.1% to 38.1 % as a function of their roughness value from 3.12 μm to 4.02 μm. On the other hand, in the case of aggregation tests, while the turbidity values decreased from 40.6 NTU to 32.1 NTU at 1x10-6 M DAH concentrations for rounder particles, it was found as 36.2 NTU to 31.8 NTU for rougher ones. The overall results of this study indicated that tuning the morphology of quartz particles may be used to adjust both the flotation and aggregation rate of particles.

9

Zabezpieczenie konstrukcji podatnych pracujących w warunkach wysokiej abrazji

Kościńska Ewa

Ochrona przed Korozją

|

2021

|

nr 5

140--143

PL

Konstrukcje gruntowo-powłokowe z blach profilowanych stosowane są w budownictwie infrastrukturalnym na obiekty o różnym przeznaczeniu: mosty, wiadukty, przepusty, tunele, przejścia dla pieszych i zwierząt. W zależności od zastosowania i towarzyszącego mu środowisku obiekty takie narażone są na różne warunki korozyjne. Czynnikami rzutującymi na tempo korozji będą agresywne środowisko atmosferyczne, wysoki stopień zasolenia atmosfery/wody, strefa zmiennego zanurzenia, szybki przepływ wody niosącej materiał skalny, stały kontakt z glebą. W zależności od warunków w jakich pracować ma dany obiekt, dobiera się odpowiednie zabezpieczenie antykorozyjne. W artykule przedstawiono zabezpieczenie konstrukcji przepustu wodnego z blach falistych narażonego na abrazję na przykładzie zrealizowanego obiektu w Estonii.

EN

Soil steel structures made of corrugated plates and sheets are used in infrastructure construction for structures of various use: bridges, viaducts, culverts, tunnels, pedestrian and wildlife underpasses. Depending on the use and associated environment, these structures are exposed to various corrosion conditions. Elements that influence the rate of corrosion are aggressive atmosphere, high salinity of water and air, splash zone, fast water flow that caries bed load material, constant contact with soil. Depending on the conditions where the structure will be erected, proper anticorrosion system is chosen. The article presents a protection of water culvert exposed on abrasion on the basis of the realized project in Estonia.

10

Odporność na zużycie zewnętrznych syntetycznych nawierzchni sportowych

Strąk Cezary, Sudoł Ewa

Materiały Budowlane

|

2021

|

nr 10

28--30

PL

Celem pracy było ustalenie odporności na zużycie syntetycznych nawierzchni sportowych w obiektach zewnętrznych. Przeprowadzono badania ścieralności trzech rodzajów nawierzchni – typu natrysk (SP), pełny EPDM oraz dwuwarstwowej (2S). Określono ubytek masy zarówno próbek sezonowanych w warunkach laboratoryjnych, jak i poddanych sztucznemu starzeniu polegającemu na działaniu wysokiej temperatury, w tym w środowisku wody, oraz cyklom zamrażania-rozmrażania. Wszystkie testowane rozwiązania wykazały dużą odporność na zużycie, przy czym najmniejszy ubytek masy odnotowano w przypadku nawierzchni typu SP. Nie zaobserwowano istotnego wpływu zadanych oddziaływań na rozpatrywaną właściwość.

EN

The aim of the study was to determine the wear resistance of synthetic sports surfaces for outdoor areas. The abrasion resistance tests of three types of surface were carried out – spray type (SP), full EPDM and two-layer (2S). The weight loss was determined for both samples seasoned in laboratory conditions and those subjected to artificial aging involving the action of high temperature, including in the water environment and freeze-thaw cycles. All tested solutions showed high resistance to wear, with the smallest weight loss recorded for the SP surface. No significant influence of the given exposures on the considered property was observed.

11

A Study on Tribological Behaviour of Electro Discharge Deposited ZE41A Magnesium Alloy Using Wear Map

Elaiyarasan U., Satheeshkumar Vinaitheerthan, Senthilkumar Chinnamuthu

Archives of Metallurgy and Materials

|

2021

|

Vol. 66, iss. 2

391--396

EN

The paper studied the tribological behaviour of electro discharge deposited ZE41A magnesium alloy using wear map. The wear experiments are conducted using pin on disc technique for different parameters such as applied load (1.5 kg-3.5 kg), sliding speed (100 rpm-200 rpm) and sliding time (3 min-7 min). Wear mechanism map is constructed by taking the applied load on y-axis and sliding speed on x-axis. The wear mechanism map is utilized to study the dominance of particular wear mechanism that dominates particular wear regimes such as mild wear, severe wear and ultra severe wear. It is observed that the wear rate increased with increased the applied load and sliding speed. Various mechanisms such as abrasion, oxidation, delamination and melting are identified through scanning electron microscope (SEM).

12

Changes in Abrasive Wear Resistance During Miller Test of Cr-Ni Cast Steel with Ti Carbides Formed in the Alloy Matrix

Tęcza G.

Archives of Foundry Engineering

|

2021

|

Vol. 21, iss. 4

110--115

EN

Austenitic chromium-nickel cast steel is used for the production of machine parts and components operating under corrosive conditions combined with abrasive wear. One of the most popular grades is the GX2CrNi18-9 grade, which is used in many industries, and mainly in the chemical, food and mining industries for tanks, feeders, screws and pumps. To improve the abrasion resistance of chromium-nickel cast steel, primary titanium carbides were produced in the metallurgical process by increasing the carbon content and adding titanium, which after alloy solidification yielded the test castings with the microstructure consisting of an austenitic matrix and primary carbides evenly distributed in this matrix. The measured hardness of the samples in both as-cast conditions and after solution heat treatment was from 300 to 330HV0.02 and was higher by about 40-70 units compared to the reference GX2CrNi18-9 cast steel, which had the hardness of 258HV0.02. The abrasive wear resistance of the tested chromium-nickel cast steel, measured in the Miller test, increased by at least 20% (with the content of 1.3 wt% Ti). Increasing the Ti content in the samples to 5.3 and 6.9 wt% reduced the wear 2.5 times compared to the common GX2CrNi18-9 cast steel.

13

Taphonomy of Pleistocene large mammal remains in the deposits of river Raba, southern Poland

Jach Renata, Wojtal Piotr

Annales Societatis Geologorum Poloniae

|

2021

|

Vol. 91, No. 2

167--187

EN

An assemblage of 120 mammal remains of Pleistocene age has been collected from the fluvial deposits of river Raba at a gravel pit in the village of Targowisko, 30 km east of Kraków, southern Poland. Nearly 100 remains represent woolly mammoth Mammuthus primigenius. Other remains belong to four or five such mammal species as horse Equus ferus, woolly rhinoceros Coelodonta antiquitatis, red deer Cervus elaphus and steppe bison Bison priscus or aurochs Bos primigenius. Pleistocene coarse-grained deposits containing isolated bones, teeth and tusks occur in the lowermost part of the fluvial succession in the open pit, presently inundated by groundwater. The surfaces of the majority of bones and teeth show abrasion damages by fluvial transport, including their rounding and smoothing as well as scratches and grooves. Traces of carnivore activity are visible on mammoth and horse bones. The location, dimension and shape of these marks suggest wolf or cave hyena gnawing.

14

Wybrane zagadnienia projektowania, wykonawstwa oraz użytkowania betonowych posadzek przemysłowych w aspekcie ich ścieralności

Świątek-Żołyńska Sylwia, Majewski Tomasz, Niedostatkiewicz Maciej

Przegląd Budowlany

|

2020

|

R. 91, nr 6

36--43

PL

Posadzki są elementem, którego stan techniczny wpływa zarówno na bezpieczeństwo użytkowania, jak również na komfort eksploatacyjny obiektu budowlanego. Jednym z najbardziej popularnych rozwiązań w zakresie betonowych posadzek przemysłowych są posadzki z impregnacją górnej powierzchni z zastosowaniem suchej posypki nawierzchniowej (DST – z ang. Dry Shake Topping). W następstwie błędów i niedociągnięć zarówno projektowych, jak i wykonawczych oraz niewłaściwej eksploatacji posadzki betonowe mogą ulegać przyśpieszonej dekapitalizacji. W artykule opisano najczęściej popełniane błędy przyczyniające się do nadmiernej ścieralności betonowych posadzek przemysłowych, których górna powierzchnia została zabezpieczona suchą posypką nawierzchniową oraz podano sposób ich usuwania. Przedmiot artykułu stanowi również dyskusja na temat współczesnych metod diagnostyki betonowych posadzek przemysłowych w zakresie oceny ich ścieralności.

EN

Floors are an element whose technical condition affects both the safety of use and the operational comfort of a building. One of the most popular solutions in the field of concrete industrial floors are floors with impregnation of the upper surface using dry topping (DST – Dry Shake Topping). As a result of errors and shortcomings in both design and execution, as well as improper operation, concrete floors may undergo accelerated decapitalization. The paper describes the most common mistakes contributing to excessive abrasion of industrial concrete floors whose upper surface has been secured with dry topping and a method of removing them. The subject of the paper is also a discussion on contemporary methods of diagnostics of concrete industrial floors in the scope of assessing their abrasion.

15

Investigation of the Tribological Behaviors of Upholstery Woven Fabrics after Abrasion

Akgun Mine

Autex Research Journal

|

2020

|

Vol. 20, no. 2

110--120

EN

Fabric surface tribology is an important area of study in upholstery fabrics, which is exposed to high friction and abrasion effects. In the studies on the tribology of upholstery fabrics, it is ensured that criteria such as better performance, less degradation, increased usage time, and user comfort are determined and taken into consideration in the woven fabric design. Surface roughness and friction coefficients are important parameters used in determining abrasion, deformation, and wear behaviors of fabrics. In this study, the surface abrasion behaviors of upholstery fabrics woven with basic and jacquard weave patterns and also different structural parameters were investigated in terms of the changes in surface roughness parameters (amplitude parameters: Ra, Rpm, and Rvm and hybrid parameters: Δa) and the changes in surface friction coefficients. These results were also related to the state of the visual changes in the fabrics. Rpm, Rvm, and Δa being roughness parameters were found to be important in the evaluation of the surface deformation of the fabrics after abrasion besides the Ra parameter. Results showed that the Δa roughness parameter could be suitable for evaluating the deformation of the textile structures to be used, particularly in sensitive applications.

16

Cavitation erosion and sliding wear of MCrAlY and NiCrMo coatings deposited by HVOF thermal spraying

Szala M., Walczak M., Łatka L., Gancarczyk K., Özkan D.

Advances in Materials Science

|

2020

|

Vol. 20, nr 2(64)

26--38

EN

The investigation into wear resistance is an up-to-date problem from the point of view of both scientific and engineering practice. In this study, HVOF coatings such as MCrAlY (CoNiCrAlY and NiCoCrAlY) and NiCrMo were deposited on AISI 310 (X15CrNi25-20) stainless steel substrates. The microstructural properties and surface morphology of the as-sprayed coatings were examined. Cavitation erosion tests were conducted using the vibratory method in accordance with the ASTM G32 standard. Sliding wear was examined with the use of a ball-on-disc tribometer, and friction coefficients were measured. The sliding and cavitation wear mechanisms were identified with the SEM-EDS method. In comparison to the NiCrMo coating, the MCrAlY coatings have lower wear resistance. The cavitation erosion resistance of the as-sprayed M(Co,Ni)CrAlY coatings is almost two times lower than that of the as-sprayed NiCrMoFeCo deposit. Moreover, the sliding wear resistance increases with increasing the nickel content as follows: CoNiCrAlY < NiCoCrAlY < NiCrMoFeCo. The mean friction coefficient of CoNiCrAlY coating equals of 0.873, which almost 50% exceed those reported for coating NiCrMoFeCo of 0.573. The as-sprayed NiCrMoFeCo coating presents superior sliding wear and cavitation erosion resistance to the as-sprayed MCrAlY (CoNiCrAlY and NiCoCrAlY) coatings.

17

The influence of positioning deposited beads direction to resistance on grind wear plates’ abrasive wear

Szymura Michał, Różański Maciej

Welding Technology Review

|

2019

|

R. 91, nr 5

11--16

EN

The article presents the results of the study of the significance of influence of positioning deposited beads towards direction of abrasive movement, to resistance on grind wear plates HARDPLATE 100S’ abrasive wear. The study on relevance of influence was conducted by using completely randomized design. The range of study has covered testing the metal-material abrasive wear resistance, macroscopic and microscopic metallographic examination and hardness tests.

PL

W artykule przedstawiono wyniki badania istotności wpływu kierunku ułożenia ściegów względem kierunku ruchu ścierniwa na odporność na zużywanie ścierne szlifowanych płyt trudnościeralnych HARDPLATE 100S. Badanie istotności wpływu prowadzono stosując program statyczny randomizowany kompletny. Zakres badań obejmował badanie odporności na zużywanie ścierne typu metal-minerał, badania metalograficzne makro- i mikroskopowe oraz pomiar twardości warstwy napawanej.

18

Renowacje zdegradowanych posadzek przemysłowych w budynkach wielkogabarytowych – analiza metod badań

Ksit Barbara, Nowak Joanna

Przegląd Budowlany

|

2019

|

R. 90, nr 9

51--54

PL

W artykule przedstawiono posadzki przemysłowe poddawane zmiennym dynamicznym obciążeniom, które wpływają negatywnie na ich stan i pogłębiają degradację. Przeanalizowano dwie metody badania posadzek na ścieralność– badanie BCA oraz badanie na tarczy Boehemego – które w przybliżony sposób pokazały odporność płyty posadzki na ruch kołowy pochodzący z kół twardych, niepneumatycznych, np. od wózków transportowych. Pokazano przykład realizacji renowacji posadzki przemysłowej poprzedzonej przeprowadzeniem badań odporności na ścieranie.

EN

The article presents industrial floors subjected to variable dynamic loads, which have a negative impact on their condition and deepen degradation. Two methods of examination of abrasion floor – BCA examination and research on Boeheme disk – were analyzed, which roughly showed the resistance of the floor slab to circular motion originating from hard, non-pneumatic wheels, e.g. from transport trolleys. An example of the renovation of the industrial floor preceded by the tests of resistance to abrasion is shown.

19

Susceptibility of various tektite types to fluvial abrasion

Brachaniec Tomasz

Geological Quarterly

|

2019

|

Vol. 63, No. 1

150--161

EN

Tektites are glass bodies, rich in silica, resulting from the impact of a large bolide into ground rocks. Similar to other impactites they are prone to erosive processes, including fluvial abrasion. This study reports the results of an experimental tumbling that aimed at estimating the potential distance that tektites from different strewn fields (moldavites, bediasites and indochinites) and Libyan Desert Glass (LDG) can withstand depending on the experimental conditions. The present study consisted of 15 cycles, in which the type of sample deposits (i.e. sand/gravel ratio) and computed transport velocity were changed, the latter being estimated at 2.5-6.5 km/h. The results clearly confirm the susceptibility of tektites to abrasion during tumbling. None of the tektites withstood the estimated distance of 12 km during the experiment, but this may have been the result of the relatively small initial size of the glasses (~1.5 g). These experiments document that LDG, despite its even smaller initial size in the experiments, can resist abrasion and fragmentation better than the tektites, thus, could probably be transported farther in a stream environment. This is most likely caused by a much higher silica content in relation to the tektites from other groups. The estimated maximum transport distances, over which moldavites, bediasites and indochinites survived in the experiments, are all very similar. The greatest weight loss for all the specimens was found after the first estimated 2 km of tumbling. This is undoubtedly caused by the irregular initial shape of the tektites and LDG. Subsequent observations recorded minor weight losses, in association with more and more rounded glass shapes. The results of the study should be treated only as a general scheme for the fluvial abrasion of tektites, due to the inability to accurately reproduce the natural fluvial environment.

20

Badanie wytrzymałości betonu z przetworzonym kruszywem z recyklingu

Kasagani Hanuma, Sali Tanuja, Rao C. B. K.

Cement Wapno Beton

|

2019

|

R. 22/84, nr 3

238--247

PL

W pracy zbadano wpływ kruszywa z recyklingu, poddanego sortowaniu, czyszczeniu, ścieraniu w bębnie Devala, myciu i suszeniu na właściwości betonu. Zbadano właściwości fizyczne tego kruszywa, wpływające na właściwości mieszanki betonowej oraz betonu stwardniałego. Ustalono zależność pomiędzy ciężarem właściwym, nasiąkliwością i ilością przylegającej do kruszywa starej zaprawy dla różnych poziomów zastąpienia kruszywa naturalnego kruszywem z recyklingu, aby umożliwić skrócenie czasu potrzebnego do przeprowadzenia badań wstępnych kruszywa. Badano mieszanki betonowe o dwóch klasach wytrzymałości, w których odpowiednio 0%, 25%, 50%, 75% i 100% kruszywa naturalnego zastąpiono kruszywem z recyklingu. Kruszywo to było poddane ścieraniu w bębnie Devala przez dwie i cztery godziny. Zastosowanie kruszywa poddanego ścieraniu przez dwie godziny spowodowało poprawę wytrzymałości do maksymalnie 7% dla klasy wytrzymałości M25 i 20% dla klasy wytrzymałości M35 w porównaniu z betonem zawierającym kruszywo niepoddane ścieraniu. Zastosowanie kruszywa poddanego ścieraniu przez cztery godziny spowodowało zmniejszenie wytrzymałości betonu. Mieszaniny zawierające kruszywo poddane ścieraniu wykazywały lepszą urabialność w porównaniu do mieszanek betonowych z kruszywem z recyklingu, które nie było poddane ścieraniu.

EN

In this study the influence of processed recycled aggregate which has undergone grading, cleaning, attritioning, washing and drying on the properties of concrete was examined. The physical properties of recycled aggregate which may affect the fresh and hardened properties of concrete were also investigated. A relation has been established between the specific gravity, water absorption and the amount of adhered mortar for the natural aggregate substitutions with recycled aggregate to lessen the time required for carrying out these preliminary tests on coarse aggregate. Concrete mixes with 0%, 25%, 50%, 75% and 100% replacement and attrition period of two and four hours for two grades of concrete have been considered in the study. The two hour attrition period showed improvement in strength to a maximum of 7 % for M25 grade and 20% for M35 grade, whereas, loss of strength was observed for recycled aggregate concrete mixes containing aggregate attritioned for four hour. Mixes incorporating recycled aggregate subjected to attritioning exhibited improved workability comparing to concrete mixes with recycled aggregate not subjected to attrition.