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1

Enhancement of tensile performance of concrete by using synthetic polypropylene fibers

Jienmaneechotchai Thunyawee, Foytong Piyawat, Khunkitti Pirat, Sata Vanchai, Chindaprasirt Prinya

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2023

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Vol. 32, No. 4

320--337

EN

The research attempted to investigate the effect of polypropylene fibers (PP fibers) on the mechanical characteristics of concrete. According to ASTM C39/C39M and ASTM C 1609/C1609M, standard testing methods were used to examine the concrete compressive and flexural strength, post-cracking behavior, and toughness. The mechanical properties were evaluated at different ages of concrete curing, namely 1 day, 7 days, and 28 days, and for different quantities of fiber volume portions, specifically 0.0%, 0.5%, and 1.0%. The results demonstrate that a fiber volume of 0.5% is the most effective in obtaining the highest compressive strength. The recorded values at the related testing ages were 31.07 MPa, 41.51 MPa, and 46.68 MPa. Additionally, the utilization of 0.5% and 1.0% volume of PP fiber in concrete resulted in improved flexural strength and post-cracking performance. The toughness values for these mixes were 2.0 and 2.6 times higher than those for the plain concrete. Upon analyzing the fracture surface, there was a homogeneous distribution of fibers, which played a significant role in enhancing the overall functionality of the concrete. The research validated that the inclusion of polypropylene fibers substantially enhanced the mechanical characteristics of concrete, emphasizing the potential of fiber reinforcement in concrete-based implementations.

2

Effect of hybrid steel-polypropylene fiber on punching shear behavior of flat slab with an opening

Zaezue Shahzinan J., Hadi Waleed K.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2023

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Vol. 32, No. 1

3--17

EN

This research aimed to gain a better understanding of how the addition of fiber influences the punching shear capacity of two-way slabs by conducting an experiment into the structural behavior of flat slabs with and without a square opening using different volume fractions of hybrid steel-polypropylene fiber (0%, 0.9%, 1.05% and 1.8%). Ten 700 × 700 × 70 mm slabs were divided into five pairs, with two samples used as control samples (with and without openings), and eight other samples with different volume fraction of fibers. Results showed that an increase in fiber content enhanced the shear strength of the slabs. For example, as the volume fraction of hybrid fiber increased from 0.0 to 1.8%, the ultimate load increased by 52% for slabs without an opening and up to 42% for slabs with an opening.

3

Prediction of concrete life under coupled dry and wet-sulfate erosion based on damage evolution equation

Nie Nan

Archives of Civil Engineering

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2023

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Vol. 69, nr 4

679--692

EN

In a corrosive environment with coupled dry-wet-sulfate action, concrete structures are susceptible to erosion by sulfate ions, which seriously affects the safe operating life. To forecast the operational lifetime of concrete below the influence of the dry-wet cycle and sulfate erosion environment, four different admixtures of polypropylene fiber: 0, 0.6, 0.9, and 1.2 kg/m3, were incorporated into concrete specimens, and indoor accelerated tests were designed to observe the macroscopic and microscopic deterioration law analysis of concrete specimens; using the precept of damage mechanics, the damage of concrete under solubility cycle was established. The damage evolution equation of concrete under freeze-thaw cycles was established and the operational life of concrete was predicted. The results showed that the overall mass loss rate of concrete specimens increased with the number of tests, and the relative energetic modulo decreased with the number of tests; the pore change pattern, microstructure, and internal material composition of specimens under different working conditions were obtained by using NMR scanning technique, SEM electron microscope scanning technique and XRD physical phase analysis technique. The damage evolution equation shows that adding a certain amount of polypropylene fiber to concrete can improve the working life of concrete under dry and wet connected sulfate assault.

4

The impact of polypropylene fibre addition on the CBR value

Dobrzycki Patryk

Architecture Civil Engineering Environment

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2023

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Vol. 16, no. 2

81--88

EN

The classic test for soil or aggregate bearing capacity in road construction is the CBR test. The results of the CBR were determined for gravelly sand and sand with the addition of 1.5% cement, as well as for their mixtures with 18 mm long polypropylene fibres in the amounts of 0.1%, 0.2% and 0.3%. The effect of compaction and time of curing of samples stabilised with hydraulic binder were also determined. The natural soil without cement and fibre additions had relatively high CBR values. The additions of 0.1% and 0.2% polypropylene fibres to the dry mass of the soil resulted in an approximately 2-fold increase in the CBR value for the samples compacted using the standard method. Increasing the amount of fibres to 0.3% caused a reduction in the CBR value to that obtained without fibre addition. For samples compacted using the modified Proctor method, the observations are different. Only the sample with 0.2% fibre addition achieved a slightly higher CBR value. Moreover, the addition of 1.5% cement and the length of treatment increased the CBR values.

5

Mechanical properties of concretes modified with steel fibers and polypropylene

Helbrych Paweł

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2022

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nr 71 (143)

56--63

EN

This paper presents the effect of the addition of steel and propylene fibers on the mechanical properties of floor concretes (compressive and tensile strengths in the bending test). The polypropylene fibers used in the tests (fibrillated and single fibers) are dosed in the amount of 0.5 kg/m3 to 2 kg/m3 , and the straight and hooked steel is dosed from 10 kg/m3 to 25 kg/m3 . It is shown that, after 28 days of maturation, the highest compressive strength is achieved by concretes containing the addition of 25 kg/m3 of hook-like steel fiber. In addition, the influence of the fiber content on the consistency of the concrete mix and workability is investigated. It was shown that the amount of steel fibers dosed in the tests, regardless of their shape, did not adversely affect the consistency and workability of the concrete mix. On the other hand, the addition of polypropylene fibers has a significant impact on the characteristics of the concrete mix. The addition of 2 kg/m3 of polypropylene fibers caused the change of consistency from S4 to S1/S2 and worsened the workability of the mixture. All of the tested series of the concrete are created using the same technology. The concrete production technology reflects the concrete production technology for flooring concretes.

6

Durability of hybrid fiber reinforced concrete at various environmental media

Elhawary Eslam Ibrahim Nasr, Elsafoury Ashraf Hassan, Ahmad Seleem Saleh Elsayed

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2022

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Vol. 31, No. 2

88--100

EN

Fiber’s addition to concrete mixture attracts researchers to determine the effect of fiber type on durability properties of hybrid performance concrete. In the present work, steel and polypropylene fibers are used in hybrid form in the experimental program. The objective of this paper is to investigate the mechanical properties of hybrid fiber reinforced concrete subjected to four various media: air, water, sodium chloride, and magnesium sulphate with a 7% concentration. The results showed that using hybrid fibers which consist of 1% steel fiber and 0.3% polypropylene fiber improved the compressive strength, splitting tensile strength, and flexural strength for different media for up to 360 days.

7

Zastosowanie fibrobetonu z włóknami polipropylenowymi w przestrzeniach publicznych

Blazy Julia, Drobiec Łukasz, Blazy Rafał

Izolacje

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2022

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R. 27, nr 6

128--131

PL

Główną rolą, jaką odgrywają włókna polipropylenowe w strukturze betonu, jest redukcja zarysowań oraz zwiększenie wytrzymałości na rozciąganie i zginanie. Pozytywny wpływ dodatku włókien do betonu jest również zauważalny w badaniach ciągliwości oraz wytrzymałości na ścieranie, uderzenia, odłupywanie oraz cykle zamarzania i odmrażania. Natomiast mniejsza porowatość, przepuszczalność i absorbcja wody pozwalają na przedłużenie trwałości elementów ze zbrojeniem rozproszonym. Fibrobeton z włóknami polipropylenowymi jest to zatem materiał o zwiększonej wytrzymałości, trwałości i bezpieczeństwie. Jego duża atrakcyjność wynika również z możliwości produkowania elementów w różnych rozmiarach, kształtach i barwach, a zredukowany ciężar jest dodatkowym atutem. Przestrzeń publiczna jest obiecującym obszarem zastosowania betonu zbrojonego włóknem polipropylenowym. Wykorzystuje się go bowiem do tworzenia paneli chodnikowych i drogowych, paneli ściennych, m.in. barier dźwiękochłonnych, elementów nabrzeży, promenad, bulwarów nadmorskich, fontann, oczek wodnych, stołów, ławek, donic, koszy na śmieci, rzeźb, płaskorzeźb, portali dekoracyjnych drzwi i okien, sztucznych skał, plaż, klifów, egzotycznych krajobrazów oraz skateparków i boisk.

EN

The main task of polypropylene fibres in the concrete texture is to reduce cracks and increase tensile and flexural strength. The positive effect of the addition of fibres to concrete is also noticeable during the tests of toughness and resistance to abrasion, impact, spalling as well as freeze-thaw cycles. On the other hand, lower porosity, permeability and water absorption allow to extend the life of the elements with dispersed reinforcement. Polypropylene fibre reinforced concrete is therefore a material with increased strength, durability and safety. Thanks to the possibility of producing elements in various sizes, shapes and colours, as well as the reduced weight is an additional advantage it is a very attractive material. There is a great potential for application of polypropylene fibre reinforced concrete in public spaces, as it can be used to produce sidewalk and road panels, wall panels, including soundproof barriers, elements of quays, promenades, seaside boulevards, fountains, ponds, tables, benches, flower pots, litter bins, sculptures, bas-reliefs, door and window decorative portals, artificial rocks, beaches, cliffs, exotic landscapes, as well as skate parks and sports grounds.

8

Szacowanie odkształceń skurczowych w fibrobetonie w świetle wybranych norm

Bacharz Magdalena, Bacharz Kamil, Raczkiewicz Wioletta

Inżynieria i Budownictwo

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2022

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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.

9

Comparison of Colour Properties of Polypropylene and Poly-(Lactic) Acid Fibres Dyed With Photoluminescent Dye

Ujhelyiová Anna, Jančovičová Viera, Panák Ondrej, Hrabovská Veronika, Tomčíková Zita

Fibres & Textiles in Eastern Europe

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2022

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Vol. 30, no. 5

17-27

EN

Every manufacturer wants to protect their textile products and their brand. A possible solution is, for example, the insertion of fibres with special pigments visible under irradiation by UV light into the final product. The paper focused on the study of the structure and colourimetric properties of polypropylene (PP) and poly-(lactic) acid (PLA) fibres modified with photoluminescent dye and halloysite (HNT) modified with photoluminescent dye. The photoluminescent dye and HNT modified with photoluminescent dye affected the structure of PP and PLA fibres differently. Increasing the HNT content up to 0.15 % increased the orientation of the PP fibres. In the case of PLA fibres, the increased content of photoluminescent dye in PLA fibres increased their orientation in the observed concentration area. PLA-based knitted fabrics showed better light stability, where there was no visible degradation of the knitted fabric, only its darkening. Likewise, PLA-based knitted fabric showed luminescence in UV light even after accelerated light aging.

10

Effect of nano-kaolinite weight fraction on interfacial shear strength of fibre reinforced nanocomposite

Hasan Hisham Mohammed Ali, Hasan Bahaa Aldin Abass

Composites Theory and Practice

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2022

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R. 22, nr 1

16--20

EN

Many studies around the world focus on the use of organic and inorganic additions to polymer composites to enhance their mechanical properties. Investigations were conducted to study the mechanical properties of composites with nano-kaolinite weight fractions of 1, 3, 5, 7, and 12% incorporated into an epoxy matrix. Further investigations were carried out on the diffusion of the epoxy nano-kaolinite monomer into the interfibrillar space when polypropylene and Kevlar rope fibre were added. The Kevlar fibre/matrix and polypropylene fibre/matrix interfacial shear strength was evaluated by the single fibre drag-out method. The highest interfacial shear strength was observed at a 5 wt.% nano-kaolinite content. Energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM), as well as characterisation by X-ray diffraction (XRD), were performed on all the epoxy/nano-kaolinite, Kevlar specimens.

11

Zachowania kotew chemicznych montowanych w różnych rodzajach betonu

Çalişkan Özlem, Karakurt Cenk, Aras Murat, Kaya Turgut

Cement Wapno Beton

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2022

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R. 27, nr 5

330--345

PL

Kotwy chemiczne znajdują szerokie zastosowanie w dodatkowych instalacjach żelbetu budowlanego, pracach naprawczych i zbrojeniowych. Dzięki coraz większej różnorodności materiałów i poprawie wiadomości na temat produktów odpadowych, możliwe stało się produkowanie różnych rodzajów betonu, o różnych właściwościach. W tym badaniu pręty żebrowane klasy B420C o średnicy 16 mm, zostały osadzone w czterech różnych rodzajach betonu, przy użyciu czterech różnych klejów chemicznych, a następnie zastosowano siłę rozciągającą. Wyznaczono sztywność, współczynnik plastyczności, zdolność do pochłaniania energii i siły rozciągającej oraz oceniono stopień zniszczenia na podstawie krzywych obciążenie-przemieszczenie, uzyskanych w wyniku doświadczeń. Stwierdzono, że siła rozciągająca i zdolność do pochłaniania energii wzrosła w wyniku osadzenia kotew i przyłożenia do betonu siły rozciągającej, uzyskanej przez dodanie materiałów domieszkowych do betonu referencyjnego. W części analitycznej wykorzystano sformułowanie podane w ACI 318, zidentyfikowano nośność i wytrzymałość obliczeniową oraz określono ich poziomy bezpieczeństwa, w porównaniu z wynikami badań.

EN

Chemical anchors are widely used in additional installations of construction irons, repair and reinforcement work. Due to the increasing diversity of materials and the improved awareness of waste products, it has become possible to produce different kinds of concrete, with various properties. In this study, class B420C ribbed bars with 16 mm diameter, were installed in four different concretes by using four different chemical adhesives, and a tensile force was applied. The stiffness, displacement ductility ratio, energy-dissipation capability and tensile force values were determined and the failure modes were interpreted from the load-displacement curves, obtained as a result of the experiments. It was found that the tensile force and energy-dissipation capacity, had increased as a result of installing anchor and applying a tensile force to the concrete, that was obtained by adding admixture materials, to the reference concrete. In the analytical part of the study, the formulation provided in ACI 318 was used, capacity and design strengths were identified, and their safety levels were determined in comparison with the test results.

12

Influence of Waste Toothbrush Fiber on Strength and Freezing–Thawing Behavior in High Plasticity Clay

Isik Fatih, Akbulut R. Kagan, Zaimoglu A. Sahin

Studia Geotechnica et Mechanica

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2021

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Vol. 43, nr 1

15--21

EN

The use of waste materials in civil engineering applications has gained importance nowadays. Consuming limited natural resources and increasing waste disposal costs have led researchers to evaluate waste materials for different geotechnical applications. In this respect, some waste materials are used as reinforcement in soils to improve their engineering properties. The main objective of this paper was to investigate the usability of waste polypropylene fiber as a reinforcement material in high plasticity fine-grained soils. For this purpose, waste toothbrush bristle (WTB) was used as a polypropylene fiber reinforcement material and added to fine-grained soil at ratios of 0.2%, 0.4%, 0.6% and 0.8% by dry total weight. The effect of WTB on freezing–thawing behavior and unconfined compression strength of unreinforced and reinforced clayey soil was evaluated. The results indicated that addition of WTB to high plasticity clay improved its behavior against freezing–thawing. Also, undrained shear strength increases with respect to increment in WTB ratio.

13

Shear performance of reinforced self-compacting concrete beams incorporating steel and polypropylene fibers

Alkhattat Saja S., Al-Ramahee Munaf A.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2021

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Vol. 30, No. 4

537--551

EN

The impact of steel and polypropylene fibers on the performance of lightweight self-compacting concrete (LWSCC) beams was investigated in this study. Seven beams with various parameters were cast and tested. Partial (50%) and full (100%) replacement of coarse aggregate with lightweight aggregate expanded clay (LECA) were considered. In addition, a 1% volumetric ratio of steel or hybrid (steel and polypropylene) fiber was added to LWSCC beams to study their effect on the shear performance. The LWSCC beams had a decrease in ultimate load and stiffness of 23 and 30% for partial and full replacement, respectively when compared to normal weight beam. The addition of steel fiber improved the efficiency of LWSCC beams in terms of crack formation, failure mode, crack width, and ultimate load, as well as changed the failure mode from shear to flexure. The ultimate load for hybrid LWSCC was increased by around 6% for a partial replacement and 13% for full replacement as compared to beams without fibers. However, hybrid beams had a larger bearing capacity, little more cracks with smaller size, and ductile failure.

14

Experimental Study on the Durability Characteristics of Several Vegetable Fiber Reinforced Concretes Exposed to Sodium Sulfate

Ziane Sami, Khelifa Mohammed-Rissel, Mezhoud Samy, Beroual Ahmed, Medaoud Saber

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 1

1--28

EN

Recently, numerous plant fibers have been investigated as a means to reinforce concrete and replace synthetic fibers, thereby producing more eco-friendly concretes. The primary concern for these studies is the durability of the fibers in the external environment. For this purpose, the current paper presents a comparison study on the physical-mechanical behavior and durability against external sulfatic attack on Alfa and Hemp fiber-reinforced concrete. To assess the effects of sulfatic attack, different types of concrete underwent two aging protocols: 1) a complete immersion in 12.5 % Sodium Sulfate (Na2SO4) solution and, 2) an accelerated aging protocol which consisted of immersion/drying in the same sulfate solution at a temperature of 60°C. The results show that the optimal amount of plant fiber is variable, depending on several parameters such as the chemical composition, mechanical characteristics, and morphology of the fiber. In addition, the results show that the use of Alfa and hemp fibers could facilitate the production of green and durable structural concretes.

15

Effect of dosing with propylene fibers on the mechanical properties of concretes

Helbrych Paweł

Budownictwo o Zoptymalizowanym Potencjale Energetycznym

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2021

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Vol. 10 Nr 2

39--44

EN

The article deals with the suitability of polypropylene fibers in concrete mixtures and the impact related to the amount of dosing of such fibers. The amount of addition in the range from 0.5 to 2.0 kg/m3 was analyzed and the effects of dosing too little or too much fiber in concrete in terms of its mechanical strength were discussed. The test fibers were made of white polypropylene arranged in bundles 50 mm long. The samples were tested after 28 days of maturation, and the mechanical properties that were assessed included, the compressive strength and the tensile strength of the concrete in a bend test. The influence of the amount of fibers on the consistency of the concrete mixture was also investigated. The results were statistically analyzed and presented in the article.

16

Wpływ dodatku włókien polipropylenowych do środka gruntującego na wytrzymałość na odrywanie powłoki z żywicy epoksydowej

Kampa Łukasz, Sadowski Łukasz

Materiały Budowlane

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2020

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nr 11

40--41

PL

W artykule przeanalizowano wpływ dodatku włókien polipropylenowych do środka gruntującego na wytrzymałość na odrywanie powłoki z żywicy epoksydowej. Włókna dodawano do środka gruntującego w ilości 0,5; 1; 1,5 i 2% w stosunku do masy żywicy epoksydowej z utwardzaczem. Zmodyfikowany środek gruntujący naniesiono na podkład z zaprawy cementowej, a następnie nałożono powłokę. Uzyskane wyniki badań porównano z powłoką referencyjną na podkładzie zagruntowanym środkiem bez dodatku włókien. Na podstawie badań zaobserwowano wzrost wytrzymałości na odrywanie powłoki na podkładzie pokrytym środkiem gruntującym z dodatkiem 0,5 oraz 1% włókien polipropylenowych, w stosunku do powłoki referencyjnej.

EN

The article presents an analysis of the addition of polypropylene fibers to the bonding agent on the pull-off strength of coating made of epoxy resin. The fibers were added to the bonding agent in an amount of 0.5%, 1%, 1.5% and 2% in relation to mass of the epoxy resin. The modified bonding agent was laid on substrate made of cement mortar and then the coating was laid. The obtained results were confirmed with the reference coating – without the addition of polypropylene fibers to the bonding agent. Based on the obtained results the increase of the pull-off strength of coatin made with the addition of 0.5 and 1% of polypropylene fibers to the bonding agent in relation the reference coating.

17

Impact of elevated temperature on the properties of concretes reinforced with Alfa fiber

Mihoub Imane, Khelifa Mohammed-Rissel, Mezhoud Samy

Civil and Environmental Engineering Reports

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2020

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Vol. 30, no. 3

161--185

EN

Alfa fiber reinforced concretes are not used to their full potential due to the limited information on their properties, especially in more severe environments. In this study, the effects of elevated temperature on the properties of concretes reinforced with Alfa fiber were analyzed. The influence of fiber length on reinforced concretes is mainly investigated. For this purpose, five types of structural concretes were formulated; two types of concrete reinforced with 1% Alfa fiber volume using two different fiber lengths of 20 mm and 30 mm (AC-20, and AC-30), and three control concretes, two polypropylene fiber reinforced concretes (PC) using the same fiber length (PC-20, PC-30), and one ordinary concrete (OC). The results showed that with the increase of temperature, the mechanical performance decreased and the porosity rose continually for all mixtures. However, the use of Alfa fiber with a length of 20 mm showed the optimal results in terms of compressive and tensile strength, even at temperatures of 600°C. This finding suggests that Alfa vegetable fiber can be used to produce more sustainable concretes with acceptable mechanical properties compared to the use of polypropylene fiber, even under severe conditions of elevated temperature

18

Compression behaviour of polypropylene fibre reinforced cellular light weight concrete masonry prism

Vijayalakshmi Ramalingam, Ramanagopal Srinivasan

Civil and Environmental Engineering Reports

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2020

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Vol. 30, no. 1

145--160

EN

Sustainable development of the built environment in developing countries is a major challenge in the 21st century. The use of local materials in the construction of buildings is one of the potential ways to support sustainable development in both urban and rural areas where burnt clay bricks are used predominantly. This work focuses mainly on the use of polypropylene micro fibers in ordinary Cellular Lightweight Concrete blocks. The main objective is to develop a high-performance fibre reinforced cellular concrete to provide a better alternative than clay bricks for structural applications of masonry. This paper presents the stress-strain behaviour of polypropylene fibre reinforced Cellular Lightweight Concrete stack bonded prisms under axial compression. Masonry compressive strength is typically obtained by testing stack bonded prisms under compression normal to its bed joint. Use of micro-fibres enhances the pre-cracking behaviour of masonry by arresting cracks at micro-scale in the post-peak region. These efforts are necessary to ensure that CLC blocks become more accepted in the world of building materials and considered as a reliable option for providing low-cost housing.

19

A study of the durability of concrete reinforced with hemp fibers exposed to external Sulfatic attack

Ziane Sami, Khelifa Mohammed-Rissel, Mezhoud Samy

Civil and Environmental Engineering Reports

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2020

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Vol. 30, no. 2

158--180

EN

The purpose of this paper is to study the durability of concrete reinforced with hemp fibers in the face of external Sulfatic attack. For this purpose, five types of concrete were formulated; three types of concrete reinforced with hemp fibers (HC-0.25, HC-0.5, and HC-1) at 0.25%, 0.5%, and 1 % of hemp fibers in volume, respectively. And two control concretes, being ordinary concrete (OC) and polypropylene fiber reinforced concrete (PC). To assess the sulfatic attacks, the described concrete types underwent two aging protocols: 1) a complete immersion in 12.5 % Sodium Sulfate (Na2SO4) solution, and 2) an accelerated aging protocol consisting of immersion/drying in the same sulfate solution at a temperature of 60°C. The results show that concrete reinforced with 0.25 % of hemp fibers is the optimal amount compared to control concretes in terms of physico-mechanical performance and durability under sulfate attack. This number of fibers could enable the production of green and durable structural concretes based on untreated hemp fibers.

20

The influence of polypropylene fibres on the properties of fresh and hardened concrete

Chajec Adrian, Krzywiński Kamil, Ostrowski Krzysztof, Sadowski Łukasz

Technical Transactions

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2019

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Vol. 116, iss. 5

71--82

EN

The purpose of the article is to determine the effect of the addition of polypropylene fibres on the properties of concrete mixtures and hardened concrete. To this end, both destructive and non-destructive tests were conducted. The concrete mixture tests included the testing of the consistency, air content and bulk density of the concrete mixture. Investigations of hardened concrete were based on the determination of compressive strength by destructive tests, sclerometer and ultrasonic methods and tensile strength in bending tests. All tests were performed for seven series of concrete mixtures, differing in their fibre content. The results showed that the addition of polypropylene fibres to the concrete mixture causes changes in consistency, increases air content, and does not increase the compressive and tensile strength of concrete. It was also observed that the addition of polypropylene fibres does not cause significant changes in the bulk density of the concrete mix.

PL

Tematem artykułu jest określenie wpływu dodatku włókien polipropylenowych na właściwości mieszanki betonowej oraz betonu stwardniałego. W tym celu przeprowadzono badania świeżej mieszanki betonowej oraz betonu stwardniałego (niszczące oraz nieniszczące). W skład badań mieszanki betonowej wchodziły: badanie konsystencji mieszanki betonowej, badanie zawartości powietrza w mieszance betonowej, badanie gęstości objętościowej mieszanki betonowej. Badania betonu stwardniałego opierały się na pomiarze wytrzymałości betonu na ściskanie, wytrzymałości betonu na rozciąganie przy zginaniu, wytrzymałości betonu na ściskanie metodą sklerometryczną oraz wytrzymałości betonu na ściskanie metodą ultradźwiękową. Wszystkie badania zostały wykonane dla siedmiu serii mieszanek betonowych, różniących się od siebie zawartością włókien. Dodatek włókien polipropylenowych do mieszanki betonowej powoduje zmiany jej konsystencji oraz podwyższenie w niej zawartości powietrza. Włókna polipropylenowe nie powodują istotnych zmian gęstości objętościowej mieszanki betonowej.