Wyniki wyszukiwania - BazTech

1

Influence of compressive strength and curing time of fibre reinforced concrete on its residual flexural tensile strength

Witkowski Paweł, Kuczma Mieczysław, Demby Michał, Rudnicki Tomasz

Advances in Science and Technology. Research Journal

|

2025

|

Vol. 19, no. 4

329--341

EN

Compressive strength is the basic parameter determining the quality of concrete. The addition of fibers to concrete allows us to create a composite with unique properties. The resulting fiber concrete can be tested in many ways, and one of the most interesting and still developing parameter is the residual flexural tensile strength. The current market situation in the construction industry in Central and Western Europe related to the problem of obtaining qualified manual workers and the prices of building materials encourage the design and thorough testing of increasingly complex products, including modern concrete. The relationship between compressive strength and residual strength is an unexplored area that is worth developing in scientific studies. The article presents the relationship between the compressive strength of designed fibre reinforced concrete and its residual flexural tensile strength. The test program included the analysis of concrete in compressive strength classes: C16/20, C25/30, C30/37 and C70/85 made of cement CEM II/B-V 42.5 R - HSR/NA and CEM I 42.5 N - MSR/NA. In each of the designed concrete classes, two types of hook-shaped steel fibres with variable slenderness (l/d ratio) of 50 and 67 were used. Fibre dosage was also diversified and set at 20, 30, 40 and 45 kg/m3 of the concrete mixture. Residual strength tests were performed in accordance with PN-EN 14651 using the ARAMIS device for digital image correlation. The experimental findings showing the relationship between the compressive strength of concrete and its residual flexural tensile strength are included. The experimental data obtained show that increasing the compressive strength class of concrete does not result in an evident increase in the residual flexural tensile strength. The research also analyzed the influence of curing time of concrete on its residual strength, including tests after 28, 180 and 360 days after concreting. The obtained results confirm the significant influence of steel fibres in transferring bending loads. The influence of sample maturation time on the compressive strength of the designed fibre concrete was also confirmed.

2

Zastosowanie włókien z recyklingu opon w technologii betonu

Michalik Agnieszka, Kupisz Piotr, Zacharski Łukasz, Pichór Waldemar

Przegląd Budowlany

|

2024

|

R. 95, nr 4

87--90

PL

Zastosowanie włókien z recyklingu opon samochodowych jest przedmiotem wielu prac naukowo-badawczych z powodu korzystnych właściwości betonów z ich dodatkiem. Wyróżnić można trzy aspekty stosowania włókien z recyklingu opon: środowiskowy (zagospodarowanie odpadów, redukcja śladu węglowego, który ma bardzo wysokie wartości dla produkcji komercyjnej stali), ekonomiczny (włókna z recyklingu opon są tańsze niż włókna stalowe komercyjne) oraz aspekt wytrzymałościowy (wykazano dobrą skuteczność zbrojenia betonu włóknami z opon). Aby jednak zastosować włókna z opon do betonu, muszą być poddane odpowiedniej obróbce technologicznej. W pracy przedstawiono wyniki badań betonów z zastosowaniem oczyszczonych włókien z recyklingu opon, w porównaniu z włóknami przemysłowymi.

EN

Application of recycled tyre fibres is the subject of many scientific and research works due to the beneficial properties of concretes with their addition. Three aspects of the use of recycled tyre steel fibres can be distinguished: environmental (waste management, reduction of the carbon footprint, which has very high values for the production of commercial steel), economic (recycled tire fibers are cheaper than commercial steel fibres) and durability (shown good concrete reinforcement with tire fibers). However, in order to use tyre fibres for concrete, they must be subjected to appropriate technological treatment. The paper presents the results of testing concretes with the use of purified recycled tyre steel fibers in comparison with manufactured fibers.

3

Wpływ wysokiej temperatury na wybrane cechy wytrzymałościowe drobnokruszywowego fibrokompozytu

Głodkowska Wiesława, Lehmann Marek, Laskowska-Bury Joanna

Materiały Budowlane

|

2024

|

nr 1

1--6

PL

W artykule przedstawiono analizę wpływu wysokiej temperatury na wybrane właściwości mechaniczne drobnokruszywowego mineralnego kompozytu ze stalowym zbrojeniem rozproszonym. Zaprojektowany fibrokompozyt charakteryzuje się właściwościami zbliżonymi bądź lepszymi niż beton zwykły i może być z powodzeniem wykorzystany do wykonywania nośnych elementów żelbetowych. Zmianę wytrzymałości na ściskanie i wytrzymałości resztkowych na rozciąganie przy zginaniu fibrokompozytu określono w temperaturze pokojowej i wyznaczonej wg krzywej pożarowej imitującej narastanie temperatury w trakcie rzeczywistego pożaru. Program badawczy obejmował także ocenę ubytku masy próbek fibrokompozytu wygrzewanych w piecu. Badania wykazały, że dodatek włókien stalowych do mieszanki kompozytu w ilości 1,2% przyczynia się do zachowania jego właściwości mechanicznych po wystawieniu na działanie temperatury do 550°C z powodu pożaru, a tym samym jest w stanie poprawić jego stabilność strukturalną w wysokiej temperaturze. Włókna stalowe znacznie poprawiają ognioodporność drobnokruszywowego kompozytu.

EN

The paper presents an analysis of the influence of high temperature on selected mechanical properties of finely aggregated mineral composite with dispersed steel reinforcement. The designed fibrecomposite has properties similar to or better than ordinary concrete and can be successfully used to make load-bearing reinforced concrete elements. The change in compressive strength and residual tensile strength during bending of the fibrecomposite was determined at room temperatures and determined according to the fire curve imitating the temperature build-up during a real fire. The research program also included the assessment of the weight loss of fibrecomposite samples annealed in the furnace. Studies have shown that the addition of steel fibers to the composite mix in the amount of 1.2% contributes to the preservation of its mechanical properties when exposed to temperatures up to 550°C due to fire, and thus is able to improve its structural stability at high temperature. Steel fibers significantly improve the fire-retardant properties of the fine-aggregate composite.

4

Innowacyjne zastosowanie włókien w betonie: Metody badań i projektowania nośności na ścinanie

Krassowska Julita, Wolka Paweł

Cement Wapno Beton

|

2024

|

R. 29, nr 2

93--107

PL

Celem przeprowadzonych badań jest ustalenie, modelu zniszczenia dwuprzęsłowych belek ze zbrojeniem rozproszonym w postaci włókien stalowych i bazaltowych. Badania doświadczalne dwuprzęsłowych belek o przekroju 120×300 mm i długości 4150 mm koncentrowały się na określeniu zmian zachowania badanych elementów na ścinanie w zależności od ilości zbrojenia oraz rodzaju włókien. Belki posiadały zróżnicowany rozstaw strzemion. Zawartość włókien stalowych wynosiła 78,5 kg/m3 [1,0%], a włókien bazaltowych 5,0 kg/m3 [0,19%]. Badano także belki betonowe bez włókien. Aby ocenić wpływ dodatku włókien na nośność na ścinanie, wykonano obliczenia nośności belek ze zbrojeniem podłużnym i zbrojeniem rozproszonym w postaci włókien bazaltowych lub stalowych, zgodnie z zaleceniami norm PN-EN 1992-1-1 (1), fib Model Code 2010 (2,3), German Committee for Reinforced Concrete DIN 2012 (4) oraz RILEM TC 162-TDF 2003 (5).

EN

The aim of the conducted research is to determine the failure model of two-span beams with dispersed reinforcement in the form of steel and basalt fibers. Experimental studies of two-span beams with a cross-section of 120×300 mm and a length of 4150 mm focused on observing changes in the behavior of the tested elements depending on the amount of shear reinforcement and the type of fibers. The beams had varied stirrup spacing. The content of steel fibers was 78.5 kg/m³ [1.0%], and the content of basalt fibers was 5.0 kg/m³ [0.19%]. Concrete beams without fibers were also tested. To assess the impact of the presence of fibers on shear capacity, calculations of the load-bearing capacity of beams with longitudinal reinforcement and dispersed reinforcement in the form of basalt or steel fibers were carried out in accordance with the recommendations of standards PN-EN 1992-1-1 (1), fib Model Code 2010 (2,3), German Committee for Reinforced Concrete DIN 2012 (4), and RILEM TC 162-TDF 2003 (5).

5

Badania odkształceń pełzania wysokowytrzymałej zaprawy cementowej modyfikowanej włóknami stalowymi

Bywalski Czesław

Materiały Budowlane

|

2023

|

nr 11

46--50

PL

Celem artykułu było przedstawienie wyników, prowadzonych przez 1,5 roku, badań odkształceń pełzania wysokowytrzymałej zaprawy cementowej modyfikowanej włóknami stalowymi. Badano zaprawy z zawartością włókien: 0, 50, 100 i 150 kg/m3. Dodatek włókien nieznacznie zmniejszył odkształcenia pełzania, jednak stopień ich redukcji nie zależał istotnie od ich ilości. Wyniki badań mogą służyć rozszerzeniu baz danych dotyczących pełzania kompozytów cementowych, które aktualnie są zbyt skromne, by było na ich podstawie możliwe opracowanie nowych lub zmodyfikowanie istniejących modeli empirycznych pełzania, na co zwraca się uwagę w publikacjach dotyczących przedstawianej tematyki.

EN

The aim of the article was to present the results of creep deformation tests conducted for 1.5 years on high-strength cement mortar modified with steel fibers. Mortars with fiber contents of 0, 50, 100 and 150 kg/m3 were tested. The addition of fibers slightly reduced the creep strains, but the degree of their reduction did not depend significantly on the fiber content. The research results can be used to expand the databases on the creep of cement composites, which are currently too modest to enable the development of new or modification of existing empirical models of creep, which is emphasized in current publications on the presented topic.

6

Flexural performance of hybrid fiber reinforced cement-based materials incorporating ceramic wastes

Wu Lipeng, Li Xuanhao, Deng Hai

Archives of Civil Engineering

|

2023

|

Vol. 69, nr 3

491--506

EN

Ceramic waste generated by demolition and manufacturing processes is a kind of widely discharged solid waste; its sustainable use can reduce resource extraction, energy consumption, and carbon emissions, thereby reducing the environmental impact. In this study, ceramic powder and ceramic sand were prepared using waste ceramic wall tiles. By using three water-to-binder ratios of 0.30, 0.32, and 0.34, five ceramic powder replacement rates of 10% to 50%, and completely using ceramic sand as the fine aggregate, specimens with large differences in mechanical properties were prepared. Firstly, the compressive strength was investigated. On this basis, hybrid fibers were employed to strengthen the new matrix material, and its bending resistance was experimentally studied. It was found that the incorporation of ceramic powder reduced the compressive strength of the matrix. The water-binder ratio significantly affects compressive strength at an early age. The effect of PVA fiber on improving the ductility of the new composite is distinct. Increasing the amount of steel fiber can effectively enhance the bending bearing capacity. With a ceramic powder dosage of 50%, the new composite has shown ductile failure characteristics, even with low total fiber content. The bending properties of this new composite material, which makes extensive use of ceramic waste, are well adjustable. The bearing capacity and ductility balance can be achieved with the steel fiber content of 1% and the PVA fiber content of 1.2% to 1.50%.

7

Influence of Abrasive Treatment of Steel Fibers on the Effectiveness of Anchoring in Concrete

Janikowska Dorota

Rocznik Ochrona Środowiska

|

2022

|

Tom 24

83--96

EN

The article presents an original proposal to improve the efficiency of anchoring steel fibers in fibroconcrete mixtures. The expected effect was obtained by developing the surface of the fibers by mechanical abrasive treatment with electrocorundum. The main part of the work presents the results of the conducted experimental studies. The effect of the surface treatment of the fibers was investigated through metallographic techniques, using a metallographic microscope and equipment to determine the surface roughness. On the other hand, the direct method of assessing the effectiveness of fiber anchoring in the concrete was determined using the pull-out test. The results of these studies were subjected to detailed analysis and statistical processing. The results of metallographic and pull-out tests indicate that the proposed method of treating the fibers significantly affects their anchoring efficiency in the concrete matrix. According to the author, this may be of great practical importance because the discussed method of treating the fibers can significantly improve the general properties of fibrocomposite mixtures.

8

Ocena przyczepności włókien stalowych do matrycy betonowej po ich obróbce mechanicznej

Krystosik Dorota

Materiały Budowlane

|

2022

|

nr 11

1--5

PL

W artykule podjęto próbę oceny przyczepności stalowych włókien do matrycy cementowej po ich obróbce mechanicznej, która polegała na rozwinięciu powierzchni pobocznicy przez obróbkę ścierną przy użyciu elektrokorundu. W pierwszym etapie badań dokonano oceny powierzchni włókien (przed i po obróbce ściernej) za pomocą technik metalografii. Wykonano, a następnie porównano obrazy powierzchni włókien w skali mikro, jak również określono chropowatość powierzchni włókien. Drugi etap badań dotyczył bezpośredniej oceny przyczepności włókien do matrycy betonowej metodą pull-out.

EN

In the article was attempt to evaluate the adhesion of steel fibers to the concrete matrix after their mechanical treatment. The processing of the fibers consisted of developing on of their surface by an abrasive treatment with the use of electrocorundum. In the first stage of the research, the surface of the fibers was assessed (before and after abrasion treatment) using the selected metallographic techniques. A micro scale images of the fibers surface were made and compared, as well as the surface roughness of the fibers was determined. The second stage of the research concerned the direct evaluation of adhesion using the pull-out test.

9

Szacowanie odkształceń skurczowych w fibrobetonie w świetle wybranych norm

Bacharz Magdalena, Bacharz Kamil, Raczkiewicz Wioletta

Inżynieria i Budownictwo

|

2022

|

R. 78, nr 11-12

558--562

PL

W pracy przedstawiono próbę odkształceń skurczowych betonu z dodatkiem włókien stalowych i propylenowych na bazie wybranych norm. Przyczyną podjęcia tego tematu jest brak przepisów normowych pozwalających na prognozę skurczu w fibrobetonie. Obliczone wartości odkształceń skurczowych porównano z wartościami doświadczalnymi i ukazano możliwość ich szacowania w fibrobetonie, bazując na wybranych podejściach normowych.

EN

The paper presents a study of shrinkage deformation of concrete with the addition of steel and propylene fibers based on selected standards. The reason for taking up this topic is the lack of normative standards that would allow predicting the shrinkage of fiber concrete. The calculated values of shrinkage deformations were compared with experimental values and the possibility of their estimation in fiber concrete based on selected standard approaches was shown.

10

Effect of Waste Fines and Fibers on the Strength and Durability Performance of Silica Fume Based Reactive Powder Concrete

Renisha M., Sakthieswaran N.

Fibres & Textiles in Eastern Europe

|

2022

|

Vol. 30, no. 1 (151)

43--49

EN

The demand and consumption of conventional concrete materials is increasing day by day, which in turn leads to the extinction of natural resources. Certain researchers tend to draw a circle to solve this global problem by finding alternative materials satisfying all aspects, mainly efficiency, eco-friendly and economical. The present research work aimed to study the combined use of coal bottom ash (CBA) and waste concrete powder (WCP) in silica fume based reactive powder concrete (SF-RPC) subjected to thermal curing. The replacement of cement by silica fume was limited to 20% and the fine aggregate quartz sand replaced by CBA and WCP varied from 5% to 25% each. The material composition of SF-RPC involves the exclusion of coarse aggregates and the inclusion of finer materials with micro-steel fibers. The steel fibers played a significant role in order to obtain a ductile and stable product of SF-RPC. The experimental investigation on SF-RPC comprised of the determination of fresh concrete properties such as slump flow and the compaction factor, as well as mechanical properties like compressive strength, flexural strength and split-tensile strength. The study was also extended to investigate durability properties such as water absorption, sorptivity and resistance to acid attack. The results showed that silica fume proves to be a feasible alternative to partially replace cement and also that optimum incorporation of pre-treated and processed CBA and WCP attains better mechanical and durability performance without compromising the necessary qualities.

11

Cyclic behavior of precast concrete beam-column connection using steel fiber reinforced cast-in-place concrete

Noorhidana Vera Agustriana, Forth John P.

Materials Science Poland

|

2021

|

Vol. 39, No. 2

240--251

EN

Three equivalent exterior precast concrete beam-column (PCBC) connections have been investigated in this study in orderto analyze the effect of steel fiber reinforced concrete (SFRC) as cast-in-place (CIP) on the seismic performance of the PCBC connection. The connection was designed as a ductile connection for a moment-resisting frame and consists of a precast U-beam, precast column with corbel, interlocking bars, and CIP-concrete to connect the precast beam to precast column. The volume fractions of steel fiber incorporated within the CIP-concrete were 0%, 0.5% and 1%. A quasi-static load was applied vertically to the beam tip of the PCBC specimen. The results showed that the steel fibers contained within the CIP-concrete provided 2% increase of the maximum load, 17.7% increase of the energy dissipation, and increase in the joint stiffness of the PCBC connection. The steel fibers delayed the onset of cracking and slowed down the crack propagation, resulting in shorter cracks in the joint core of PCBC specimen, which correlates well with the deflection-hardening characteristic found from the modulus of rupture test.

12

Confinement effectiveness of CFRP strengthened ultra-high performance concrete cylinders exposed to elevated temperatures

Abadel Aref A., Alharbi Yousef R.

Materials Science Poland

|

2021

|

Vol. 39, No. 4

478--490

EN

Fire-related damage is an alarming concern to reinforced concrete (RC) structures throughout their service lives. When exposed to extreme temperatures, concrete can endure severe damage. Given that a complete replacement and/or demolition of fire-damaged structures can be an economic waste, a more viable option for extending the service life of the damaged structures involves repairing or strengthening the damaged members. Due to its more efficient qualities over conventional concrete, the use of concrete, such as ultra-high-performance concrete (UHPC) in the building industry, has dramatically grown in recent years. However, limited information is available about the confinement behavior of the unheated and heated UHPC members, particularly when wrapped with fiber-reinforced polymers (FRP). This paper investigates the effect of carbon fiber reinforced polymer (CFRP) sheet strengthening on the compressive strength of both UHPC and ultra-high-performance fiber reinforced concrete (UHPFRC). In this study, strengthening has been considered for the UHPC cylinders before and after they were subject to an elevated temperature of 400°C, and they were left to cool by air cooling. Six UHPC mixes, which were made without the use of fibers, steel fibers (SF) alone, a hybrid system of SF and polyethylene alcohol (PVA), in addition to a hybrid system of steel, PVA, and polypropylene (PP) fibers were tested. Regarding the plain and various fiber-reinforced UHPC both at room temperature and after being exposed to 400°C, the ultimate compressive strength of CFRP-confined concrete has shown an increase by 25% to 33% and 52% to 61%, respectively compared with the unheated specimens.

13

Cost-Benefit Analysis of Using Recycled Coarse Aggregate In Plain and Fiber Reinforced Concrete

Awchat Ganesh Deoraoji

Advances in Science and Technology. Research Journal

|

2021

|

Vol. 15, no. 3

233--242

EN

The tendency of demolition has increased to improve economic gains, functional and structural performance, and unloading expenses due to the inaccessibility of an appropriate site in a nearby area. As a result, effective utilization of construction and demolition waste materials in the form of a Recycled Coarse Aggregate of 20 mm & 10 mm is possible while conserving non-renewable natural resources. Even though recycled coarse aggregate (RCA) is a cost-effective material that provides solutions to solid waste management, it is also viewed as second-rate in terms of its basic properties compared to natural coarse aggregate (NCA). This study attempted to design two mix proportions for natural aggregate concrete (NAC) and recycled aggregate concrete (RAC). RAC supplemented with Hooked Steel Fibers at a rate of 0%, 0.25%, 0.5%, and 0.75% per cubic metre. Compressive strength considered a benefit parameter, whereas the state schedule of rates (SSR), 2020-21, was used to estimate cost. The experimental results discovered that RAC with 0.25% steel fibres(SF) per cubic metre found 7.27% less compressive strength results than NAC in Mix-1 of M25 grade, whereas it is 11.64% less compared to NAC of Mix-2 of M40 grade at 28 days, respectively. This related decrease in compressive strength compared to NAC is within the acceptable limit of Indian Standards. At the same time, cost analysis of RAC with 0.25% steel fibres per cubic metre observed 1.26% and 2.16% more than NAC of M25 & M40. It revealed that 0.25% SF per metre cube in RAC provides an economically viable solution in terms of cost and benefits compared to NAC of a similar mixture.

14

Effects of steel fibres on fresh and hardened properties of cement concrete

Ali Saqib, Kumar Haresh, Rizvi Samar Hussain, Raza Muhammad Saleem, Ansari Jawaid Kamal

Civil and Environmental Engineering Reports

|

2020

|

Vol. 30, no. 3

186--199

EN

Concrete possesses distinct features that make it widely acceptable for use across the globe; however, along with its obvious benefits, it has numerous drawbacks i.e., it is brittle in nature and its production causes an adverse impact on the environment. To counter such problems, researchers around the world have introduced sustainable measures. Fibre addition is foremost among these solutions in that it prevents crack propagation and increases the overall strength of concrete. In the present age, civil engineering structures have their own structural and durability requirements and so, modification in traditional concrete has become a necessity. This research is targeted at steel fibre reinforced concrete (SFRC), which is a superior quality concrete because of its enhanced strength. The steel fibres are obtained from binding wire that is used to tie the steel reinforcement. By referring to past research, steel fibres with an aspect ratio (length to diameter ratio) of 30 were considered favourable. The controlled, mixed design of the concrete was prepared with a targeted strength of 4000 psi and, while mixing the concrete ingredients, fibres were added to allow uniform dispersion. The fresh and hardened properties of workability, compressive, and tensile strength were tested and the results of fibres at 0%, 1%, 2% and 3% concrete mass were compared and analysed. The results indicated that highest compressive and tensile strength values were achieved with 3% fibre addition. However, with further addition, it was observed that concrete loses its workability. Therefore, it is suggested that 1% addition of steel fibres produces good strength with sufficient workability.

15

Influence of maturing conditions of steel-fibre reinforced concrete on its selected parameters

Czajkowska Agnieszka, Raczkiewicz Wioletta, Bacharz Magdalena, Bacharz Kamil

Budownictwo o Zoptymalizowanym Potencjale Energetycznym

|

2020

|

Vol. 9 Nr 1

47--54

EN

In the article the impact of varying humidity conditions on selected strength properties of hardened steel fibre-reinforced concrete (such as Young’s modulus and the compressive strength of concrete) were analysed. The analysis shows that the value of the Young’s modulus of concrete cured under 100% humidity conditions is the highest; 35% higher compared to concrete hardening in the laboratory hall and about 18% higher than modulus measured in the concrete samples maturing in the chamber. A much higher compressive strength of approx. 25% was observed in samples hardening under 100% humidity conditions than in the other two environments. It was also observed that the non-uniform distribution of samples in the chamber and opening and closing the chamber during sample maturation had an impact on the dispersion of the results and due to the coefficient of variation, results can be even worse than in free-maturing samples.

16

The effect of the concentration of steel fibres on the properties of industrial floors

Krzywiński Kamil, Chajec Adrian, Sadowski Łukasz

Technical Transactions

|

2019

|

Vol. 116, iss. 4

115--132

EN

This paper presents the results of a series of experiments on samples made of steel fibre reinforced concrete. The investigated samples were made with different concentrations of steel fibres ranging from 20.0 to 32.5 kg/m3. Twenty-one cubic samples (15 x 15 x 15 cm) and fourteen cuboid samples (15 x 15 x 60 cm) were used for this investigation. The article focusses on the effect of the concentration of steel fibres on the properties of industrial floors. For this purpose, both destructive and non-destructive methods were used and compared. As a result of this study, it has been proved that compressive and flexural tensile strength are lower with increasing air content and decreasing density of concrete. Moreover, it was found that there is a correlation between ultrasonic pulse velocity and rebound hammer results which together can be used to estimate the compressive strength of steel fibre reinforced concrete.

PL

W niniejszym artykule przedstawiono wyniki serii eksperymentów wykonanych na próbkach z betonu zbrojonego włóknami stalowymi. Badane próbki zbrojone były różną zawartością włókien stalowych od 20.0 do 32.5 kg/m3. Do badań użyto 21 sześciennych (15 x 15 x 15 cm) i 14 prostopadłościennych (15 x 15 x 60 cm) próbek betonowych. W artykule skupiono się na zbadaniu wpływu zawartości włókien stalowych na właściwości posadzek przemysłowych. Do badań zastosowano i porównano metody niszczące oraz nieniszczące. W rezultacie udowodniono, że wytrzymałość na ściskanie i rozciąganie przy zginaniu zmniejsza się wraz ze wzrostem zawartości powietrza i malejącą gęstością betonu. Ponadto stwierdzono, że istnieje korelacja między wynikami ultradźwiękowymi i sklerometrycznymi, które mogą być wykorzystane do oszacowania wytrzymałości na ściskanie betonu zbrojonego włóknami stalowymi.

17

Bending Moment of the Waste Fine Aggregate Concrete Beams

Domski Jacek, Zakrzewski Mateusz, Laskowska-Bury Joanna

Rocznik Ochrona Środowiska

|

2019

|

Tom 21, cz. 2

1505-1514

EN

This report presents the results of laboratory experiments of bending moment for fourteen concrete beams with steel bars. Twelve of the beams were made of waste fine aggregate concrete containing steel fibres: six with steel fibres 30/0.55 and six with steel fibres 50/0.80. The next two beams were made of plain concrete. The results of the experiments were compared with theoretical calculations based on a Eurocode 2 and also with the method suggested by Henager and Doherty.

PL

Artykuł przedstawia wyniki laboratoryjnych badań momentu zginającego czternastu belek żelbetowych. Dwanaście z nich wykonano na bazie piasku odpadowego wzbogaconego włóknami stalowymi tj.: sześć z włóknami 30/0.55 i sześć z włóknami 50/0.80. Pozostałe dwie belki wykonano z betonu zwykłego. Wyniki badań eksperymentalnych zostały porównane z obliczeniami przeprowadzonymi na podstawie Eurocode 2 i metody zaproponowanej przez Henager i Doherty.

18

Wpływ włókien stalowych na wybrane właściwości kompozytów cementowych na bazie regranulatu EPS

Polek Konrad, Zakrzewski Mateusz, Piekarski Paweł

Materiały Budowlane

|

2019

|

nr 6

72--73

PL

W artykule przedstawiono rezultaty badań wybranych właściwości mechanicznych kompozytów cementowych z dodatkiem regranulatu polistyrenu ekspandowanego i włókien stalowych. Podczas badań mieszankę modyfikowano przez zastosowanie różnej ilości zbrojenia rozproszonego (0,25% i 0,5%). Przedstawiono wpływ włókien na wytrzymałość na ściskanie, wytrzymałość na rozciąganie przy zginaniu oraz wytrzymałość resztkową kompozytu. Wykazano, że zastosowane włókna mają istotny wpływ na poprawę badanych właściwości.

EN

This paper presents choosen mechanical properties of steel fibre reinforced composite with addition of ground expanded polystyrene aggregate. During investigation, concrete mix was enchanced by addition of steel fibre (0,25% and 0,5% of mix volume). Investigation prove positive impact of fibre on compression, bending and residual flexural tensile strength of composite.

19

Wpływ włókien stalowych na właściwości mieszanek betonowych do wykonywania posadzek

Chajec Adrian

Materiały Budowlane

|

2019

|

nr 6

70--71

PL

W artykule omówiono wpływ dodatku włókien stalowych na właściwości mieszanek betonowych stosowanych w posadzkach. Przedstawiono wyniki badań mieszanki, w skład których wchodzą: pomiar zawartości powietrza w mieszance betonowej; określenie konsystencji mieszanki betonowej za pomocą metody opadu stożka oraz oznaczenie gęstości mieszanki betonowej. Badania dotyczyły siedmiu serii betonów, różniących się zawartością włókien stalowych. Na podstawie przeprowadzonych badań stwierdzono, że wraz ze wzrostem zawartości włókien w mieszance betonowej rośnie w niej zawartość powietrza. Wykazano także, że dodatek włókien ma wpływ na konsystencję mieszanki betonowej oraz że zawartość włókien stalowych w mieszance betonowej nie ma istotnego wpływu na jej gęstość.

EN

The purpose of the articleis to describe the influence of addition of steel fibers on properties of concrete mixes used in floors. The paper presents the results of a mix test including: measurement of air content in a concrete mix, determination of the consistency of a concrete mix using the slump fall method and determination of the density of a concrete mix. The tests were carried out for seven series of concrete mixes, differing from each other by dispensing steel fibers. On the basis of the tests carried out, it was found that with increasing the fibers addition to the concrete mix, the air content in it increases, it has also been shown that the dispensing of fibers has an effect on the consistency of the concrete mix, it was also found that the addition of steel fibers into the concrete mix does not have a significant impact on its density of concrete mix.

20

Fibrobeton. Wybrane wyniki badań

Grzymski Filip

Builder

|

2019

|

R.23, nr 9

5--7

PL

Zbrojenie betonu włóknami stalowymi jest coraz częściej wykorzystywaną metodą zwiększania jego odporności na zarysowanie i pękanie. Najszersze zastosowanie w praktyce znalazło ono w przypadku posadzek przemysłowych. Różnorodność dostępnych na rynku włókien pozwala na spełnienie zróżnicowanych kryteriów projektowych, a włókna stalowe najnowszej generacji umożliwiają niekiedy całkowitą rezygnację z klasycznego zbrojenia prętami, nawet w przypadku silnie obciążonych posadzek. W artykule przedstawiono wybrane wyniki badań dotyczących potencjału wykorzystania odpadów z obróbki skrawaniem jako substytutu włókien stalowych dostępnych na rynku. Podstawowe parametry wytrzymałościowe fibrobetonu uzyskanego z użyciem proponowanych włókien zostały porównane z materiałami referencyjnymi – betonem bez zbrojenia oraz fibrobetonem ze stalowymi włóknami haczykowatymi. Dodatkowo przedstawiono analizę czynników technologicznych, które mają duży wpływ na zasadność stosowania badanego materiału.

EN

Reinforcing concrete with steel fibers is an increasingly used method of improving its cracking resistance. The most common application of such kind of reinforcement is associated with industrial floors. The variety of the fibers available on the market allows to meet different project criteria. The newest generation of steel fibers makes it possible to omit classical steel rebars in some cases despite high load levels. In this paper selected research results regarding the potential of using machining wastes as a substitute to steel fibers available on the market are presented. The most important mechanical properties of proposed fiber reinforced concrete and two reference materials – concrete and typical fiber reinforced concrete are compared. Additionally, the analysis of key technological factors was carried out.