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1

A Set of Finite Elements for 2D Analysis of Reinforced Concrete Foundations on Deformable Subsoil

Szajna Waldemar

Civil and Environmental Engineering Reports

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2024

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Vol. 34, no. 2

100--116

EN

The paper presents a formulation and verification of a 2D soil – structure interaction model which enables the analysis of reinforced concrete shallow foundations under monotonic short-time loads. The structure supported by a deformable subsoil, whose elasto-plastic features are being considered. The structure model describes: the ability of crack creation, non-linear stress – strain characteristics of concrete and reinforcement and also reinforcement – concrete interaction. The foundation – subsoil contact model enables the identification of slide and adhesion zones. The presented mathematical formulation allowed for the development of a set of finite elements simulating the behaviour of the foundation, the subsoil and the contact zone between them. The elasto-plastic approach was used to describe the behaviour of the structure, the subsoil and the contact phenomena. Computer programs were prepared and verifying analyses were presented.

2

A new model for predicting the axial compression capacity of reinforced concrete cylinders strengthened with CFRP

Guo Guang, Zhou Li, Wang Bangkang

Archives of Civil Engineering

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2024

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Vol. 70, nr 1

389--404

EN

Numerous scholars have identified the shortcomings of imprecise terminology and substantial computational inaccuracies in the current models for predicting the axial compression capacity of CFRPstrengthened reinforced concrete (RC) cylinders. To improve the prediction accuracy of the axial compressive capacity model for CFRP-strengthened RC cylinders, the present axial compressive capacity model for CFRP-strengthened RC cylinders was scrutinized and evaluated. Drawing on Mander’s constraint theory and the concrete triaxial strength model, a novel axial compressive capacity model for CFRP-strengthened RC cylinders was proposed. This study collected 116 experimental data on the axial compression of CFRP-strengthened RC cylinders and analyzed the accuracy of various models using the data. The findings indicate that the model proposed in this study outperforms other models in predicting axial compression capacity and demonstrates high prediction accuracy. Furthermore, an analysis is conducted on the variation law of the model’s predicted value with respect to the design parameters. The proposed model in this study identifies concrete strength, stirrup spacing, and elastic modulus of CFRP as the primary factors that influence the axial compression capacity of CFRP-strengthened RC cylinders.

3

Diagnosis, repair, strengthening and monitoring of a postindustrial heritage site: flyover of the Odra Cement Factory

Putra Wojciech, Bednarz Łukasz, Bajno Dariusz, Opałka Piotr, Krupa Michał, Mamedov Alirza

Wiadomości Konserwatorskie

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2023

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Nr 75

144--152

EN

This paper presents a wide range of diagnostic tests, repair and reinforcement measures, as well as a proposal to monitor the technical condition of a flyover structure located in the Odra Cement Factory in Opole. The poor technical condition of the structure determined the need to prepare a design aimed at repairing the structure. Design studies were fully used during the execution phase of the work. The purpose of this study is to present the characteristics of a historical postindustrial building in urgent need of revitalization and the assumptions adopted for repair. The reason for engaging in this project was the advanced state of degradation and the danger it posed. The primary objective was to guarantee safety and preserve this structure to the highest possible degree of authenticity. This was to protect this historical structure from failure or demolition and to ensure that it could continue to be used indefinitely,

PL

Niniejszy artykuł prezentuje szeroki zestaw badań diagnostycznych, działań naprawczych i wzmacniających, a także koncepcję monitorowania stanu technicznego estakady przenośnikowej w Cementowni „Odra” w Opolu. Zły stan techniczny budowli spowodował konieczność przygotowania projektu mającego na celu naprawę konstrukcji. Studia projektowe zostały w pełni wykorzystane w fazie wykonawczej prac. Celem niniejszego opracowania jest przedstawienie charakterystyki zabytkowego obiektu poprzemysłowego, który pilnie potrzebuje rewitalizacji, a także założenia przyjęte w ramach działań naprawczych. Powodem podjęcia się projektu był zaawansowany stan degradacji i zagrożenie, które obiekt stwarzał. Głównym celem było zagwarantowanie bezpieczeństwa i zachowanie jak najwyższego stopnia autentyczności obiektu. Miało to ochronić ten zabytkowy obiekt przed katastrofą budowlaną i rozbiórką oraz zapewnić możliwość jego dalszego, bezterminowego funkcjonowania.

4

Adaptation of reinforced-concrete, postindustrial buildings in terms of thermal retrofitting on the example of a historical water tower

Opałka Piotr, Solisz Iwona, Bednarz Łukasz, Bajno Dariusz, Kuśnierz-Krupa Dominika, Wilk Kamila, Andrianos Nikolaos

Wiadomości Konserwatorskie

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2023

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Nr 74

100--108

EN

Today, the only way to save an unused historical building is to subject it to adaptive reuse. This adaptation, on the one hand, allows the historical structure to “live” and on the other it often makes it possible to raise funds for its maintenance. In the case of postindustrial historical buildings subjected to adaptive reuse, one of the important design issues is their thermal retrofitting. Industrial buildings erected at the turn of the nineteenth and the twentieth centuries were not designed in accordance with contemporary functional and technical requirements, including those concerning thermal and humidity requirements. The extent of the interventions carried out in the area of building physics can have a significant impact on the use of the building, on maintaining its durability, and on preserving the authenticity of the historical substance. The paper presents the problem of thermal retrofitting in postindustrial facilities using the example of the adaptation of a historical concrete water tower. Additionally, on the basis of adaptation experience and ex-post evaluation, the risks associated with the adaptation of this type of structure are highlighted.

PL

Współcześnie jedynym sposobem na uratowanie nieużytkowanego obiektu zabytkowego jest poddanie go adaptacyjnemu ponownemu wykorzystaniu. Adaptacja ta z jednej strony pozwala „żyć” zabytkowej budowli, z drugiej często umożliwia pozyskanie środków na jej utrzymanie. W przypadku poprzemysłowych obiektów zabytkowych poddawanych adaptacyjnemu ponownemu wykorzystaniu jednym z ważniejszych zagadnień projektowych jest ich termomodernizacja. Obiekty przemysłowe wznoszone na przełomie XIX i XX wieku nie były projektowane zgodnie ze współczesnymi wymogami użytkowymi i technicznymi, w tym z wymaganiami cieplno-wilgotnościowymi. Zakres prowadzonych ingerencji w obszarze fizyki budowli może mieć istotny wpływ na użytkowanie obiektu, zachowanie jego trwałości i autentyczności substancji zabytkowej. W artykule przedstawiono problematykę termomodernizacji w obiektach postindustrialnych na przykładzie adaptacji zabytkowej żelbetowej wieży ciśnień. Ponadto na podstawie doświadczeń związanych adaptacją oraz ewaluacją ex post, wskazano na zagrożenia związane z adaptacją tego typu obiektu.

5

Second-order effects in horizontally loaded reinforced concrete columns

Pędziwiatr Janusz, Musiał Michał

Studia Geotechnica et Mechanica

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2023

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Vol. 45, nr 4

417--429

EN

This paper deals with the second-order effects in horizontally loaded reinforced concrete columns. The current standard approach according to Eurocode 2 is the starting point for the considerations. Simplified methods that take into account the secondary effects, that is, the nominal stiffness method and the nominal curvature method, and their limitations are discussed. Most attention is devoted to the general method. As only general guidelines for this method can be found in the literature on the subject, the author presents his own original approach to calculations done using this method. Exemplary analyses for the corbel columns of high bay racked warehouses are made. Columns of different lengths are analyzed. The calculations show the overestimates introduced by the simplified methods and the benefits stemming from the use of the general method, especially in the case of quite slender columns.

6

Projektowanie wzmocnień konstrukcji murowych z wykorzystaniem systemu FRCM

Drobiec Łukasz

Izolacje

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2023

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T. 28, nr 2

58, 60, 62

PL

Tekst jest pierwszą częścią artykułu opisującego zasady projektowania wzmocnień konstrukcji murowych z wykorzystaniem systemu FRCM. Autor opisuje sposób wymiarowania wg normy włoskiej CNR-DT 215/2018, zgodnej z normami z pakietu Eurokodów.

EN

This text is the first part of the article describing the principles of designing reinforcement of masonry structures using the FRCM system. The author describes the method of dimensioning according to the Italian standard CNR-DT 215/2018, in accordance with the standards from the Eurocode package.

7

Evaluation of YLT method to estimate the load carrying capacity of one-way patched reinforced concrete slab under concentrated load

Kristiawan Stefanus Adi, Basuki Achmad, Supriyadi Agus, Santosa Bambang, Marwoto Sofa

International Journal of Applied Mechanics and Engineering

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2023

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Vol. 28, no. 1

47--57

EN

An unsaturated polyester resin (UPR) mortar was applied to repair the damage to the tension zone's one-way reinforced concrete (RC) slabs. The load carrying capacity of the patched RC slab is of interest to justify the effectiveness of the repair. The Yield Line Theory (YLT) may be used to estimate the load carrying capacity of patched RC slabs under concentrated load. The results of the YLT are compared with the experimental results to evaluate the validity of the YLT method. The results confirm that patching alters the yield line formation, mainly when the concentrated load is applied close to the patching zone. Subsequently, the YLT method provides a higher load carrying capacity estimation deviation for slabs with a loading point near the patching zone. On the other hand, the YLT method estimates load carrying capacity accurately when the loading point is away from the patching zone.

8

Increasing the Efficiency and Environmental Friendliness of Fire Resistance Assessment Tools for Load-Bearing Reinforced Concrete Building Structures

Nuianzin Oleksandr, Pozdieiev Serhii, Sidnei Stanislav, Kostenko Tetiana, Borysova Anna, Samchenko Taras

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 4

138--146

EN

In this work, it is substantiated that it is possible to create a fire installation with parameters that will ensure higher environmental friendliness of the tests compared to large-sized furnaces. At the same time, its configuration will be universal, compact and capable of high reproducibility of experimental results. A full factorial experiment was conducted. According to its results, the parameters of the furnace chamber, which most significantly affect the reproducibility of the results, were determined. This are the volume of the chamber, the distance from the burners to the surface of the examined fragment of the load-bearing reinforced concrete building structure, and the height at which the opening for the exit of combustion products is located. Adequacy of operation of the designed installation was verified by the computer simulation method. Natural gas was used as fuel. On the basis of the received data, a sketch of the installation was created for conducting the experimental part of evaluating the fire resistance of load-bearing reinforced concrete building structures under the influence of the standard fire temperature regime. It can ensure a high degree of reproducibility of the test results.

9

Effects of stirrup spacing on shear performance of hybrid composite beams produced by pultruded GFRP profile infilled with reinforced concrete

Özkılıç Yasin Onuralp, Gemi Lokman, Madenci Emrah, Aksoylu Ceyhun

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e36, 2023

EN

Pultruded Glass Fiber-Reinforced Polymer (pultruded GFRP) composite produced by the pultrusion method has become popular in civil engineering applications due to its lightness, corrosion resistance and high strength. However, the use of the pultruded profile combining with reinforced concrete is still limited due to a lack of knowledge. Therefore, the behavior of the pultruded GFRP profile infilled with reinforced concrete beams (hybrid beams) is investigated. This study focused on the effects of stirrup spacing for the hybrid beams. Pursuant to this goal, a total of eight different beams were tested under four-point loading. One reference beam without the pultruded profile and seven hybrid beams having different stirrup spacings were considered. Moreover, the hybrid beams with and without stirrups were wrapped by unidirectional GFRP composite to investigate the effects of stirrup spacing on shear capacity of the beams strengthened by GFRP composite. The experimental findings revealed that tightening stirrups increased the load and energy dissipation capacities of the hybrid beams; however, it could not prevent brittle failure. On the other hand, wrapping hybrid beams with GFRP composite increased the load and energy dissipation capacities and also prevented brittle failure regardless of the presence of the stirrups. Therefore, it is strongly recommended that the unidirectional pultruded profiles should be strengthened with 90° GFRP wrapping to have ductile behavior.

10

Bond behavior of corroded reinforcements in concrete: an experimental study and hysteresis model

Zhang Yi‑Bo, Zheng Shan-Suo, Dong Li-Guo, Zheng Yue

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e95, 2023

EN

In order to study the effect of both longitudinal reinforcement and stirrups corrosion on the bond performances at steel-concrete interface under reversed cyclic loading, in this paper, the eccentric pull-out tests under reversed cyclic loading were carried out on reinforced concrete (RC) specimens with five corrosion degrees, three concrete cover thicknesses, and three stirrup spacings. The influence of the corrosion rate of longitudinal reinforcement, corrosion rate of stirrups, cover thickness, and stirrup spacing on bond performance indicators was examined, including the initial bond stiffness, peak bond stress, slip at peak bond stress, bond strength at unloading, unloading stiffness, frictional bond resistance, and cumulative energy dissipation. Moreover, the effects of coupling corrosion on cover cracking morphology and bond degradation mechanism were also analyzed. Results indicated that after severe corrosion of longitudinal reinforcement and stirrups, the cover appears cracking or local spalling, and the bond performances are signifcantly reduced. It was also showed that thickening cover or densifying stirrups could improve the interface bond performance and energy dissipation capacity. Each hysteresis parameter degrades apparently under the controlling slip corresponding to the peak bond stress. Subsequently, based on the analysis results and previous studies, empirical local bond stress-slip hysteresis models for corroded longitudinal reinforcement and corroded stirrup under reversed cyclic loading were proposed. Good consistency was observed for the hysteresis model with existing experimental data.

11

Prediction of shear strength of CFRP-strengthened reinforced recycled aggregate concrete beams using various strengthening methods

Sahib Hiba A., Al-Asadi Ali K.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2022

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Vol. 31, No. 4

238--248

EN

Fibre reinforced polymer (FRP) strengthening is a possible option when the load carrying capacity of a structure needs to be increased for various reasons. On the other hand, the focus nowadays aims to save the environment by reducing the waste material. A suggestion was made to use waste concrete as an aggregate. If this new material was used more, it would be possible to use recycled concrete aggregate (RCA) and carbon fibre reinforced polymer (CFRP) to strengthen reinforced concrete (RC) structures and make them more environmentally friendly. An experimental investigation study on the shear behaviour of RC beams strengthened with CFRP strips was carried out. Tests were conducted on six reinforced concrete beams, with variations in the replacement ratio of RCA and strengthened by different configurations of CFRP under four-point loading. The results indicated that the load carrying capacity was increased, on average, by 18.09 and 35.04% for beams strengthened with CFRP with an inclined strip (IS) and continuous strip (CS) configurations respectively. The results also indicated that the increases in the stiffness were 21.08 and 37.31 for beams strengthened with CFRP in the IS and CS configurations, respectively. In addition the ductility of the beams increased after strengthening.

12

Mechanical properties and flexural behaviour of reinforced concrete beams containing recycled concrete aggregate

Dawood Malak H., Al-Asadi Ali K.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2022

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Vol. 31, No. 4

259--269

EN

Increasing waste recycling has become an essential process in the construction industry due to the environmental and economic advantages, such as minimizing waste in landfills, saving natural resources, and decreasing pollution. Crushing and sieving waste from standard compression test cubes is used to produce the recycled concrete aggregate (RCA). A set of standard concrete cylinders, cubes, and beam specimens were made by utilizing coarse aggregate replacement ratios of 0%, 30%, 50% and 70%. At the day 28 stage, the specimens were tested to determine compressive strength, stress–strain relationship, splitting tensile strength, and flexural strength. In addition, four reinforced concrete (RC) beams were cast and tested under a four-point load to evaluate the flexural behaviour of RC beams with partial replacement of the natural aggregate with RCA. One was a natural aggregate (NA) control beam, while the others had varying RCA ratios (30%, 50% and 70%). The results show that the compressive strength of RCA concrete with the replacement by 30%, 50% and 70% decreased by 9.10%, 18.88% and 22.57% respectively, in comparison to the compressive strength of normal concrete (NC). The RCA concrete showed a high strain capacity, which indicated high ductility. The maximum RCA type strains ranged from 0.0056 to 0.0072. Concrete flexural strength showed a slight decrease in comparison to NC (18.83% decrease), where the tensile strength showed a 10.61% decrease in comparison to NC. As for RC beams, the load-carrying capacity decreased by 10.5% with increases in the replacement ratio.

13

Analysis of the influence of electrical parameters of concrete and reinforcement inside concrete walls on the values of the electric field intensity

Choroszucho Agnieszka

Przegląd Elektrotechniczny

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2022

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R. 98, nr 8

111--117

EN

The aim of the article is to analyze the influence of the variability of the electrical parameters of non-ideal and absorbing dielectric (usual concrete) on the values of the electric field intensity. A detailed analysis was also made of the influence of the reinforcement diameter, the number of rows and the spacing between the bars on the values of the electric field intensity. The subject of the research was a model containing a loadbearing wall made of concrete (absorbing dielectric) with reinforcement in the form of steel rods (conductor). Four reinforcement systems commonly used in construction were analyzed. Additionally, the discussion covered the influence of electrical parameters (electric permittivity, conductivity) on the field intensity values calculated for heterogeneous, complex material structures. The results of the field generated by the wireless communication system operating at the frequency f = 5 GHz are presented. The numerical finite difference time domain (FDTD) method was used. The influence of the values of electric permittivity and conductivity of concrete on the field intensity values was discussed in detail.

PL

Celem publikacji jest analiza wpływu zmienności wartości parametrów elektrycznych nieidealnego i absorbującego dielektryka (beton zwykły) na wartości natężenia pola elektrycznego. Również dokonano szczegółowej analizy wpływu średnicy zbrojenia, liczby rzędów oraz rozstawu pomiędzy prętami na wartości natężenia pola elektrycznego. Przedmiotem badań był model zawierający ścianę nośną wykonaną z betonu (absorbujący dielektryk) wraz ze zbrojeniem w postaci stalowych prętów (przewodnik). Analizowano cztery, powszechnie stosowane w budownictwie układy zbrojenia. Dodatkowo dyskusji poddano wpływ parametrów elektrycznych (przenikalność elektryczna, konduktywność) na wartości natężenia pola obliczone dla niejednorodnych, złożonych struktur materiałowych. Zaprezentowane zostały wyniki pola generowanego przez system komunikacji bezprzewodowej pracujący przy częstotliwości f=5 GHz. Zastosowano numeryczną metodę różnic skończonych w dziedzinie czasu (FDTD). Szczegółowo omówiono wpływ stosowanych w literaturze wartości przenikalności elektrycznych oraz konduktywności betonu na wartości natężenia pola.

14

Ocena trwałości konstrukcji żelbetowej zagrożonej korozją

Gwoździewicz Piotr

Mosty

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2022

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nr 2

24--29

PL

Artykuł zawiera zestawienie podstawowych sformułowań opisujących postęp zjawisk korozyjnych w elementach betonowych ze zbrojeniem oraz ilustrację ich zastosowań w postaci przykładu analizy porównawczej konstrukcji, w której skonfrontowano wyniki teoretycznych oszacowań rozwoju procesów korozji z wynikami badań konstrukcji.

EN

The article contains a summary of the basic phrases describing the progress of corrosion phenomena in reinforced concrete elements and an illustration of their applications in the form of an example of the comparative analysis of structures, in which the results of theoretical estimates of the development of corrosion processes are compared with the results of structural research.

15

A review on autogenous self‑healing behavior of ultra‑high performance fiber reinforced concrete (UHPFRC)

Yao Chao, Shen Aiqin, Guo Yinchuan, Lyu Zhenghua, He Ziming, Wu Hansong

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 3

art. no. e145

EN

Ultra-high performance fiber reinforced concrete (UHPFRC) is well known for its superior workability, strength, ductility as well as durability, but its intrinsic self-healing ability is rarely valued and developed. This review focuses on the inherent potential or superiority, characterization, and mechanism of autogenous healing UHPFRC, aiming to obtain fundamental data for its mixture innovation, design, and application. High potentialities of autogenous self-healing UHPFRC depend on its excellent component requirements (fiber; abundant binding particles), mix design (high cementitious materials content, low water-binder ratio, moderate fiber content), rehydration capacity, and shrinkage or loading-initiated cracking features. Meantime, the generation of cracks makes the internal substances include active ingredients exposed to the external environment such as air, water, and temperature, which induces physical, chemical, and mechanical interaction between them at cracks. Intrinsic partial or entire sealing of the multiple cracks in UHPFRC has been proven to improve the safety and durability of UHPFRC infrastructures. A higher healing rate exists in cracks with a width of 75-175 μm, which is connected with crack healing kinetics, and the width of total healing cracks can reach up to 162 μm, which is mainly filled with calcium carbonate. Continuous accumulation of healing products at cracks can effectively improve the mechanical properties and suppress the decay of transport performance and steel fiber corrosion. Furthermore, mild fiber corrosion contributes to the partial restoration of flexural strength during the self-healing process.

16

Bamboo as a Construction Material: Prospects and Challenges

Fahim Muhammad, Haris Muhammad, Khan Wajid, Zaman Saeed

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 3

165--175

EN

Bamboo is a naturally available, fast growing and renewable resource. Bamboo plants are found all over the world in tropical and non-tropical regions. Asia pacific region is specifically rich in bamboo biodiversity. Due to high energy demand of existing construction materials and scarcity of other naturally available materials like wood, bamboo is a good alternative for construction. This paper reviews the mechanical properties and use of bamboo in construction. The tensile strength of different bamboo species varies in the range 70-210 MPa, compressive strength 20-65 MPa, elastic modulus 2500-17500 MPa, and modulus of rupture 50-200 MPa. Bamboo is a versatile material and can be used in construction in various ways. Bamboo can be engineered to specific need in construction such as laminated and scrimber bamboo. Engineered bamboo are used for various housing purposes such as roofing and flooring. Bamboo culms are often used directly without any alteration as structural members such as beams and columns. Bamboo can also be used as reinforcement in concrete as a replacement to steel. The shear and flexural behavior of bamboo reinforced concrete (BRC) beams is significantly better than plain concrete beams. Bamboo fibers reinforced concrete (BFRC) is a good alternative to existing synthetic fibers reinforced concrete such as glass and steel fibers. Development of standardized testing procedures and structural specifications utilizing existing and future research findings will pave the way towards an extensive use of bamboo in construction industry.

17

FEM modelling of the static behaviour of reinforced concrete beams considering the nonlinear behaviour of the concrete

Pazdan Maciej

Studia Geotechnica et Mechanica

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2021

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Vol. 43, nr 3

206--223

EN

This paper presents a finite element (FE) method of modelling reinforced concrete beams. The proposed model takes into account the phenomena characteristic of reinforced concrete structures, such as the interaction between two materials (concrete and steel), the cracking caused by mechanical loads and the variation of the Young's modulus under increasing load. A relevant numerical FE analysis was carried out in the ABAQUS system using the concrete damaged plasticity (CDP) model. The character of Young's modulus variation due to increasing stress intensity level was taken from the author’s own research. The results of the FE calculations were compared with the results yielded by the author's numerical bar model.

18

Skanowanie konstrukcji, wykorzystanie metody prądów wirowych i georadarowej do celów lokalizacji i detekcji zbrojenia

Giryn Stefan

Przegląd Budowlany

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2021

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R. 92, nr 10

54--57

PL

Artykuł przedstawia zyskujące w ostatnim czasie na popularności i znaczeniu elektromagnetyczne metody nieniszczące badań (skanowania konstrukcji), indukcję elektromagnetyczną zwaną też metodą prądów wirowych (Eddy Current) i metodę georadarową (GPR). Przybliżono ich zasadę działania, możliwości i ograniczenia, a przede wszystkim porównano uzyskane nimi wyniki na podstawie przeprowadzonych przez autora skanowań.

EN

Article presents the recently gaining popularity and importance electromagnetic nondestructive concrete scanning methods, electromagnetic induction (also known as eddy current or Foucault’s currents) and ground penetrating radar (GPR). It discusses their principle of operation, possibilities and limitations, and above all compares the obtained results based on the scans performed by the author.

19

Badanie właściwości mechanicznych betonu ze zbrojeniem rozproszonym z włókien syntetycznych

Blazy Julia, Drobiec Łukasz

Izolacje

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2021

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R. 26, nr 4

74--78

PL

Fibrobeton, czyli beton zbrojony włóknami, otrzymywany jest przez dodanie do mieszanki betonowej włókien metalicznych lub niemetalicznych. Przeprowadzone badania miały na celu sprawdzenie, czy norma PN-EN 14651, przeznaczona do trzypunktowego testu zginania betonowych próbek zbrojonych włóknami metalicznymi, może być również zastosowana do badań betonu z włóknami syntetycznymi. Zbadano ponadto urabialność i wytrzymałość na ściskanie betonu z włóknami i bez nich. Sprawdzono również, czy dana objętość i rodzaj zastosowanej fibry mógłby zastąpić tradycyjne zbrojenie prętami stalowymi, a więc czy badany kompozyt może pełnić funkcję konstrukcyjną. W ramach badań została przygotowana betonowa mieszanka bez włókien oraz mieszanka z dodatkiem 0,22% (2 kg/m3) włókien syntetycznych. Dla obu mieszanek ilość cementu, kruszywa, wody i superplastifikatora była identyczna. W artykule omówiono podstawy prowadzenia badań, zastosowane materiały, sposób przygotowania próbek oraz technikę badań i wyniki badań wytrzymałości na ściskanie.

EN

Fiber-reinforced concrete is obtained by adding metallic or nonmetallic fibers to the concrete mixture. The tests were carried out to check whether the PN-EN 14651 standard, intended for three-point bending test the concrete samples reinforced with metallic fibers, can also be used for testing the concrete samples reinforced with synthetic fibers. In addition, the workability and compressive strength of concrete with and without fibers were tested. It was also checked whether used volume and type of fiber could replace traditional reinforcement with steel bars, and thus whether the tested composite can function as a structure. As part of the research, concrete mixture without fibers and with the addition of 0,22% (2 kg/m3) of synthetic fibers were prepared. For both mixtures, the amount of cement, aggregate, water and superplasticizer was identical. The article presents the basics of testing, materials used, method of sample preparation as well as the test technique, and the results of the compressive strength tests.

20

Wpływ włókien polimerowych na wytrzymałość na ściskanie i rozciąganie betonu w świetle norm PN-EN 206 i PN-EN 14651

Blazy Julia, Drobiec Łukasz

Inżynieria i Budownictwo

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2021

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R. 77, nr 8

391--396

PL

Przedstawiono możliwość zastosowania normy PN-EN 14651, przeznaczonej do badania betonów z fibrą stalową, do określenia wytrzymałości na rozciąganie przy zginaniu betonów z dodatkiem 2,0 i 3,0 kg/m3 włókien polimerowych o różnej geometrii i formie. Pozostały skład mieszanki betonowej był niezmienny w przypadku każdej serii. Opisano również użyte materiały, metodykę badań oraz wyniki badań konsystencji i wytrzymałości na ściskanie betonów z fibrą i bez fibry. Przeprowadzono analizę uzyskanych wyników i podsumowano wpływ włókien niemetalicznych na właściwości betonu.

EN

In the article, the possibility of use the PN-EN 14651 standard, intended for testing concretes with steel fibers, to determine the flexural strength of concrete with the addition of 2.0 and 3.0 kg/m3 of polypropylene fibers of different geometry and form was presented The remaining composition of the concrete mix was the same for each series. Additionally, the used materials, the methodology of tests, results of consistency tests and the evaluation of the compressive strength of concrete with and without fibers were discussed. Finally, the obtained results were analyzed and the influence of non - metallic fibers on the properties of concrete was summarized.