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1

Effect of fibre content on the geotechnical properties of peat

Chmielewska Iwona

Studia Geotechnica et Mechanica

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2023

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Vol. 45, nr 2

133-143

EN

The purpose of the study was to determine the geotechnical properties of peat and relate them to the fibre content. Peat soil tested in this study was collected from the peatland in the north-eastern Poland, 250 km north-east of Warsaw. Peat samples were taken from eight different depths below the ground surface over an area of approximately 2500 m2. The research programme consisted of laboratory tests of the physical properties of peat and compressibility tests conducted in oedometers. Tests were performed in accordance with the current international and European standards using specialised research equipment. Based on the degree of decomposition, peat was divided into fibric (with more than 66% of fibres), hemic (fibre content from 33% to 66%) and sapric (less than 33% of plant fibres). The bulk and particle densities, natural water content, organic content, initial void ratio and the degree of decomposition were investigated as the physical properties of peat. Based on the oedometer tests, the constrained modulus, compression and secondary compression indexes were determined. It was concluded that the fibric peat is characterised by the lowest bulk and particle densities, the highest water and organic contents, void ratio and compressibility in comparison to hemic and sapric peat. The characteristics of peat have been related to the results presented in the literature.

2

Metoda oceny zawartości mikrowłókien polimerowych w kompozytach cementowych

Chyliński Filip

Materiały Budowlane

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2023

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nr 2

5--8

PL

Wykorzystywanie włókien polimerowych w kompozytach cementowych wymaga niekiedy przeprowadzenia weryfikacji, czy ilość dodanych włókien do mieszanki była prawidłowa i czy zostały one równomiernie rozmieszczone w całym elemencie. Oznaczanie zawartości włókien stalowych czy makrowłókien polimerowych w stwardniałej zaprawie czy betonie nie stanowi większego problemu. Natomiast oznaczenie zawartości znacznie drobniejszych mikrowłókien polimerowych jest dosyć trudne. W artykule zaprezentowano metodę oznaczania zawartości mikrowłókien polimerowych w zaprawach i betonie, która została opracowana w Instytucie Techniki Budowlanej i objęta krajową oraz międzynarodową ochroną patentową.

EN

The use of polymer fibers in cement composites requires sometimes verification whether the amount of fibers added to the mix is correct and whether they were evenly distributed throughout the whole element. Determining the content of steel fibers or polymer macrofibers in the hardened mortar or concrete is not a big problem. Although it is relatively difficult to determine the content of much finer polymer microfibers. This article presents a method for determining the content of polymer microfibers in mortars and concrete, which was developed at the Building Research Institute and was covered by national and international patent protection.

3

Fibrokompozyt z kruszywem odpadowym jako pełnowartościowy materiał konstrukcyjny

Głodkowska Wiesława, Kobaka Janusz, Laskowska-Bury Joanna

Przegląd Budowlany

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2020

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R. 91, nr 7-8

38--47

PL

W artykule poruszono problem zagospodarowania zalegających na terenie Pomorza piasków, powstających jako odpad poprodukcyjny w procesie hydroklasyfikacji. Jednym ze sposobów na jego rozwiązanie jest zastosowanie kruszywa odpadowego do wytwarzania konstrukcyjnych kompozytów ze zbrojeniem rozproszonym. Autorzy zaprezentowali wyniki badań wybranych właściwości kompozytów drobnokruszywowych o różnej zawartości włókien stalowych. Przeprowadzone badania pozwoliły dobrać taką ilość włókien, przy której fibrokompozyt wykazuje najlepsze właściwości i spełnia wymagania stawiane materiałom konstrukcyjnym. Stwarza to możliwość wykorzystania zalegających hałd piasku odpadowego, rozwiązując tym samym częściowo problem kosztownej rekultywacji terenów wyrobisk kopalnianych.

EN

In the paper a problem of waste sand deposits located in Polish Pomerania region was raised. These deposits an excavation by-product were obtained during the process called aggregate hydroclassification. One of the examples how to resolve this problem is application of waste sand for the production of steel fibre reinforced composites. The authors introduced their tests results based on selected properties of fine aggregate composites containing different fibre volume fractions. The research tests conducted on these type of composites have allowed to choose such a fibre volume fraction, at which fibre composite exhibits the best properties and meets the requirements of construction materials. The results of the research tests could create a good opportunity for the use of the waste sand and could partially solve the problem of expensive reclamation of former mine areas.

4

Zależność modułu sprężystości drobnokruszywowego fibrokompozytu od zawartości włókien stalowych

Głodkowska W., Staszewski M., Laskowska-Bury J.

Materiały Budowlane

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2017

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nr 5

85--86

PL

W artykule omówiono wpływ zawartości włókien stalowych na wartość modułu sprężystości przy ściskaniu drobnokruszywowego fibrokompozytu. Na podstawie badań ustalono zależność pozwalającą na wyznaczenie modułu sprężystości takiego materiału. Opracowana zależność wykazuje dobrą zgodność z proponowaną przez ACI 318-11 funkcją, sformułowaną dla betonów wysokiej wytrzymałości.

EN

The article presents influence the value of steel fibre in fine aggregate fibrous composites on the static modulus of elasticity. The results of the tests used established a relationship for allowing the determination of the elastic modulus of this material. Developed relationship has a good compatibility with the proposed of the ACI 318-11 for high strength concrete.

5

Wpływ włókien stalowych na kształtowanie właściwości kompozytu drobnokruszywowego

Głodkowska W., Laskowska-Bury J., Kobaka J.

Materiały Budowlane

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2013

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nr 9

28--30

PL

W artykule poruszono problem zagospodarowania piasków na terenie Pomorza powstających jako odpad przy pozyskiwaniu kruszyw mineralnych do betonu. Jednym ze sposobów na jego rozwiązanie jest zastosowanie piasków odpadowych do produkcji konstrukcyjnych kompozytów mineralnych ze zbrojeniem rozproszonym. Autorzy zaprezentowali wyniki badań wybranych właściwości kompozytów drobnokruszywowych o różnej zawartości włókien stalowych. Określono skład materiałowy takiego kompozytu. Przedstawione badania są niewielkim fragmentem realizowanego szerokiego programu badań.

EN

In the paper an issue of waste sand utilization was raised.The heaps ofwaste sand located in Polish region Pomerania are by-product obtained during the process called hydroclassification of all-in-aggregate for concrete production. One of examples how to resolve the waste sand utilization problemcould be its application for the production of steel fiber reinforced mineral composites. The authors introduced their tests results based on selected properties of fine aggregate fibrous composites with different amounts of steel fibers. The study is a small part of a broad research program.

6

Quantitative analysis of the fibre content distribution in CFRP composites using thermal non-destructive testing

Wróbel G., Rdzawski Z., Muzia G., Pawlak S.

Archives of Materials Science and Engineering

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2010

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Vol. 41, nr 1

28-36

EN

Purpose: The primary purpose of present study was to determine the fibre content distribution in CFRP composites using thermal non-destructive testing. Design/methodology/approach: The experiments have been performed using transient thermography to obtain the thermograms for CFRP and neat resin specimens. From recorded thermograms, the thermal diffusivity values were determined for all materials under investigation and for two different preheating conditions to verify the effect of preheating conditions on obtained results. Findings: It was found from obtained results that composites with different carbon fibre content had different values of thermal diffusivity. Relationship showed that the thermal diffusivity was a linear function of fibre content in considered materials. It was also found from investigated neat resin specimens that the thermal diffusivity measurement was affected by specimen thickness. Research limitations/implications: Developed relationships between thermal diffusivity and carbon fibre content is not generalized for all types of CFRP composites (manufactured using a different technology or of different thickness), such specific relationships should be determined for any other composite. Practical implications: The results obtained from present experiment would be of great importance in the industrial or laboratory applications to evaluate the fibre content distribution in carbon/epoxy composites. Originality/value: Originality of the present paper is about applying the thermal non-destructive testing to determine the fibre content distribution in CFRP composites.

7

Transient thermography in the assessment of local fibre content in CFRP laminates

Wróbel G., Rdzawski Z. M., Muzia G., Pawlak S.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 31, nr 2

385-390

EN

Purpose: The main objective of the present work was to find relationships between achieved results of the thermal non-destructive testing and the local fibre content in carbon/epoxy composite materials. Design/methodology/approach: The experiments have been performed using thermography testing station designed and built specially for the purpose of the investigation. Each carbon/epoxy composite was prepared with different fiber content with the same total thickness of the specimens. Thermal non-destructive testing (TNDT) technique was employed to measure such parameters as threshold temperature rise, upper limit temperature and temperature growth rate on the specimen surface. The results achieved were then analysed and correlated with carbon fiber content. Findings: The study has assessed the ability of transient thermography to carry out a testing of fiber content in carbon/epoxy composite materials. The experimental results revealed relationship between fiber content and temperature growth rate from which the empirical formula for predicting local fiber content has been developed. Research limitations/implications: In order to obtain reliable results, there are many factors to be considered such as void content in composite matrix, type and quality of composite surface and others. Further work is needed in this area. Practical implications: The results obtained would be of considerable importance in the industrial applications to achieve a first estimate of local fiber content in polymer composite materials. Originality/value: A new approach to the problem of fibre content examination has been demonstrated by means of thermal non-destructive testing. The method developed should be of interest to the industrial quality control applications and has a great importance for the products with a high failure-free requirements.

8

Active IR-thermography as a method of fiber content evaluation in carbon/epoxy composites

Wróbel G., Muzia G., Pawlak S.

Archives of Materials Science and Engineering

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2008

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Vol. 30, nr 2

101-104

EN

Purpose: The primary purpose of the present work was to find relationships between achieved results of the thermal non-destructive testing and the local fibre content in a carbon/epoxy composite materials. The paper also describes the methodology, a prototype testing station and results achieved during investigations. Design/methodology/approach: The experiments have been performed using a prototype testing station designed and built specially for the purpose of the investigation. Each carbon fiber reinforced plastic (CFRP) composite was prepared with different fiber content. Thermal non-destructive testing (NDT) technique was employed to measure such parameters as threshold temperature rise, upper limit temperature and temperature growth rate on the specimen surface. The results achieved were then analysed and correlated with carbon fiber content. Findings: The study has assessed the ability of IR-thermography to carry out a testing of fiber content in CFRP composite materials. The experimental results revealed relationship between fiber content and upper limit temperature and also between fiber content and temperature growth rate. Research limitations/implications: In order to obtain reliable results, there are many factors to be considered such as void content in composite matrix, type and quality of composite surface and others. Further work is needed in this area. Practical implications: The results obtained would be of considerable importance in the industrial applications to achieve a first estimate of fiber content in polymer composite materials. Originality/value: A new approach to the problem of fibre content examination has been demonstrated by means of thermal non-destructive testing. The method developed should be of interest to the industrial quality control applications and has a great importance for the products with a high failure-free requirements.

9

The effect of fiber content on the ultrasonic wave velocity in glass/polyester composites

Wróbel G., Pawlak S.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

295-298

EN

Purpose: The primary purpose of the present study was to find relationship between ultrasonic wave velocity and the fiber content in glass/polyester composites. In addition, further tests were conducted to determine how other factors can affect the ultrasonic velocity. Design/methodology/approach: Experimental data have been obtained using ultrasonic wave velocity measurements and standard destructive analysis. For ultrasonic non-destructive testing, through-transmission technique was used. Findings: Experimental results have shown that the longitudinal wave velocity increases almost linearly with an increase of the fiber content in investigated specimens. Research limitations/implications: The propagation velocity of the ultrasonic waves can be affected, apart from fiber content, by interfacial stresses and changes of elastic modulus in polymer matrix during long-lasting conditioning. These factors overlap and which of the two can affect the ultrasonic wave to a higher degree is yet to established. Further work is needed in this area. Practical implications: Ultrasonic wave velocity measurement seems to be an effective method of fiber content evaluation, but for any different composites, distinct relationships should be determined. Originality/value: The results obtained would be of considerable importance in industrial applications to achieve a first estimate of fiber content variations in composite materials.

10

A method for ultrasonic quality evaluation of glass/polyester composites

Wróbel G., Wierzbicki Ł., Pawlak S.

Archives of Materials Science and Engineering

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2007

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Vol. 28, nr 12

729-734

EN

Purpose: The aim of the present study was to find relationship between the ultrasonic wave velocity or attenuation coefficient and the local fiber content in glass/polyester composites. Design/methodology/approach: Experimental data have been obtained using ultrasonic wave velocity and attenuation measurements. To determine the actual fiber content in the composites, needed to build proper relationships between considered factors, the standard destructive analysis was applied. For ultrasonic nondestructive testing, through-transmission technique was used. Findings: Experimental results have shown that the longitudinal wave velocity increases almost linearly with an increase of the fiber content in the investigated specimens. The second considered parameter of an ultrasonic wave, namely attenuation coefficient was not correlated with the glass content. Research limitations/implications: The propagation velocity of the ultrasonic waves can be affected, apart from fiber content, by interfacial stresses and changes of elastic modulus in polymer matrix during long-lasting service time. These factors overlap and which of the two can affect the ultrasonic wave to a higher degree is yet to established. Further work is needed in this area. Practical implications: The described method can be applied to the post-production quality control of a finished composite product, but in the case of composites made of different constituent materials it is necessary to determine distinct relationships for each composite. Originality/value: The results obtained would be of considerable importance in the industrial applications to achieve a first estimate of fiber content variations in polymer composite materials.