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1

The effect of basalt fiber arrangement on the structural behavior of fiber-reinforced concrete beams in flexure

Stęplowski Tomasz, Pelczar Natalia, Ubysz Andrzej

Materiały Budowlane

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2026

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nr 3

1--9

EN

This study examines the effect of uniform (BF-UII, BF-UV) and layered basalt fiber distribution (BF-LII, BF-LV) on the flexural behavior of fiber-reinforced concrete beams at two levels of fiber content: 2 and 5 kg/m³. Reference beams without fiber reinforcement (BF-0) were also tested for comparison. Structural behavior was evaluated using load-deflection (F-δ) relationships and strains in the tensile zone determined from displacement measurements. Beams BF-LII and BF-LV exhibited higher stiffness compared with beams BF-UII and BF-UV at the same fiber content. In several cases, beams with layered fiber distribution at a lower fiber content showed flexural behavior comparable to that of beams with uniformly distributed fibers at a higher content and in certain loading ranges demonstrated higher stiffness. The observed differences may be attributed to the placement of fibers in the tensile zone, where their mechanical efficiency may be greater.

PL

W artykule przeanalizowano wpływ jednorodnego (BF-UII, BF-UV) oraz warstwowego rozmieszczenia włókien bazaltowych (BF-LII, BF-LV) na zachowanie zginanych belek fibrobetonowych przy dwóch poziomach zawartości włókien: 2 oraz 5 kg/m3. W celu porównania zbadano również belki referencyjne (BF-0) bez zbrojenia włóknami. Zachowanie konstrukcyjne oceniano na podstawie charakterystyk obciążenie-ugięcie (F-δ) oraz odkształceń w strefie rozciąganej wyznaczonych z pomiarów przemieszczeń. Belki BF-LII oraz BF-LV charakteryzowały się większą sztywnością w porównaniu z belkami BF-UII oraz BF-UV przy tej samej zawartości włókien. W kilku przypadkach belki z warstwowym rozmieszczeniem włókien, przy mniejszej zawartości zbrojenia, wykazywały porównywalną odpowiedź mechaniczną przy zginaniu w odniesieniu do belek z jednorodnym rozmieszczeniem włókien o większej ich zawartości, a w niektórych zakresach obciążeń charakteryzowały się również większą sztywnością. Zaobserwowane różnice mogą wynikać z umieszczenia włókien w strefie rozciąganej, gdzie ich efektywność mechaniczna może być większa.

2

Harnessing Agricultural Residues for Eco-Efficient Cement Substitution in Mortar: A Pathway to Low-Carbon and Sustainable Construction

Verma Mohit, Singh Kunwar Raghvendra, Gupta Nakul, Asmari Abdullah Faiz Al, Goyal Rajesh, Berwal Parveen, Islam Saiful

Rocznik Ochrona Środowiska

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2025

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Tom 27

388--401

EN

Several studies have explored the use of agricultural waste materials in construction. Using these materials in building not only eliminates them but also prevents environmental contamination. The purpose of this study is to evaluate the impact of rice husk ash (RHA) as a partial replacement of cement. An assessment was conducted to determine the compressive strength, flexural strength, porosity, water absorption, and density of the hardened samples. Furthermore, the microstructures and chemical compositions of several samples were analyzed using SEM and XRD analysis. The replacement levels of rice husk ash were 0%, 5%, 10%, 15%, 20%, 25%, and 30% by weight of cement. From the findings, it was observed that the possible utilization of RHA was up to 20 percent. The water absorption, porosity, and dry density of RHA mixed mortar samples were observed to increase with the percentage addition of RHA. This is due to the greater number of voids in RHA compared to cement. However, it decreases as curing age increases. XRD and SEM analysis matched the macro-property analysis and helped explain the positive effect of RHA. The linear regression between flexural strength and compressive strength was found to be fcr = 0.1146 fck + 1.0882, with an R² value of 0.9602. The statistical analysis using a dendrogram revealed three distinct cluster formations for the different variables.

3

Ocena morfologii powierzchni spękań rozdzielczych w piaskowcach metodą profilometrii laserowej

Rembiś Marek, Oczkowski Łukasz

Przegląd Geologiczny

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2025

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Vol. 73, nr 1

81--89

EN

This paper attempts to determine the relationship between the lithology, the type of mechanism of disintegration of sandstone samples and the morphology of the resulting separation surfaces, which has a significant impact on the magnitude of displacements occurring within the rock mass. Six lithologically different sandstones from the Carpathians, Sudetes and Holy Cross Mountains were analysed. The first element of the research was petrographic studies. The next tests consisted of carrying out strength tests, including tests of rock resistance to uniaxial compression strength and flexural strength under concentrated force. Then, a total of 12 surfaces obtained were examined using a laser profilometer. Laser profiling data was correlated with petrographic and strength test data. They showed that the strength value is influenced by the type of rock itself and that the morphology of the separation surfaces differs depending on the type of disintegration. Surfaces obtained by uniaxial compression testing are rougher than those obtained by bending forces. Moreover, the study revealed a fairly clear relationship between sandstone textures and roughness parameters of surfaces, regardless of the disintegration test. The highest roughness values are found on the surfaces of sandstones from Radków, Tumlin and Bieganów. On the other hand, there is no correlation between waviness values and rock textures. Therefore, waviness parameter is a poor tool for describing the morphology of the separation surfaces in sandstones.

4

Production of eco-friendly clay bricks from municipal construction and demolition waste

Raini Imane, Raini Imad, El Asmi Hicham, Obda Ilias, Mesrar Laila, Jabrane Raouf

Journal of Ecological Engineering

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2025

|

Vol. 26, nr 3

296--308

EN

Although rapid urbanization has improved the quality of life by enabling the development of infrastructure, and buildings, it has also contributed to a significant increase in construction and demolition waste (CDW). Traditionally, most CDW has ended up in landfills and has not sufficiently valorized, exacerbating environmental degradation. Another repercussion of the building sector is the depletion of non-renewable resources, such as clay, to meet the extensive demands for building materials. Thus, this work proposes an effective solution for valorizing various types of CDW as an alternative raw material to produce valuable fired bricks. This paper evaluates the technological properties of bricks containing concrete waste (CW), ceramic waste (EW), and glass waste (GW). These wastes were analyzed using various techniques, including X-ray diffractometry, X-ray fluorescence, differential thermal analysis, and geotechnical testing. The results showed that incorporating CW into brick bodies notably reduced the density and flexural strength compared to the reference sample, leading to an increase in the rate of capillary water absorption. Therefore, the amount of waste concrete fines added to ceramic materials must be strictly controlled. However, the addition of GW and EW was more beneficial, with adequate water absorption and a significant improvement in flexural strength, reaching 14.9 MPa for marl and 20 MPa for clay. In summary, this research highlighted the possible use of CDW as a sustainable additive for clay bricks, presenting a practical solution to reduce the costs of the construction industry and tackle both environmental and resource-related issues.

5

Utilization of asphalt plant waste powder as a partial cement replacement in concrete

Razak Rafiza Abd, Zulkifli Zuraida, Abdullah Mohd Mustafa Al Bakri, Yahya Zarina, Mydin Md Azree Othuman, Ishak Shafiq, Nabiałek Marcin, Jeż Bartłomiej

Archives of Civil Engineering

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2025

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Vol. 71, nr 2

491--501

EN

Asphalt Plant Waste Powder (APWP) is a sort of waste that asphalt mixing facilities produce in enormous amounts. These materials have the potential to cause a plethora of new health and environmental concerns; thus, they should be changed into something more useful and environmentally friendly. This substance comprising silicon and aluminium, which can be utilised as a cement substitute or in building. Utilization of APWP is a novel, since very limited research has used this material especially in concrete. This study will evaluate the use of Asphalt Plant Waste Powder (APWP) as a cement substitute in order to produce regular, usable concrete. This study aims to determine the ideal amount of cement replacement by APWP for use as a building material and to manufacture normal concrete with a density of less than 2400 kg/m3. To partially replace cement, four proposed percentages of 10%, 20%, 30%, and 40% are utilised. Compressive and flexural strength were examined at 28 days throughout the project. All specimens were water-cured prior to being examined. The optimal replacement of cement by APWP is therefore 10% with compressive strength of 53.75 MPa, density of 2456 kg/m3, Ultra Pulse Velocity (UPV) of 3.82 km/s, and flexural strength of 5.84 MPa. Consequently, it is suggested that APWP can be utilised as a cement alternative at a replacement rate of 10%.

6

Impact of using recycled fine aggregate from demolition waste on mechanical properties of cement mortar

Abed Jasim Mohammed, Al-Uzbaky Hiba A. Abdul Kareem, Abbu Muthanna

Archives of Civil Engineering

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2025

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Vol. 71, nr 4

375--392

EN

The rapid expansion of the construction industry worldwide has led to a significant increase in resource use, hence depleting the existing reserves. Utilizing recycled aggregates might potentially reduce the use of natural raw materials in the production of concrete and mortar. This would further aid in reducing the quantity of waste thrown into the environment due to demolition procedures. This study investigated the feasibility of recycling recycled fine aggregate from construction and demolition waste. Limestone powder was utilized as a filler, together with waste from three different kinds of construction and demolition waste (concrete, clay bricks, and ceramics). Cement mortar mixtures of 1:3:0.5 and 1:4:0.5 were used to design 32 different mortar mixes (cement: fine aggregate: filler). Except for the control mixes, the following replacement ratios were tested: 0%, 20%, 40%, 60%, 80%, and 100% for construction and demolition waste as a partial replacement for natural fine aggregate. Cubes, prisms, and cylinders were all used to measure the physical and mechanical properties of the mortar. In this study, the physical properties (workability, dry density) were analyzed. In addition to investigating the mechanical properties (compressive, flexural, and splitting strength), The experimental results showed that the optimal percentage of natural fine aggregate replacing recycled aggregate from construction and demolition waste was 20%. Additionally, the research demonstrated that, due to its cementitious properties, recycled fine aggregate from concrete waste significantly outperformed the reference mixes in terms of all physical and mechanical properties.

7

Optimization of fused deposition modeling parameters for polyethylene terephthalate glycol flexural strength and dimensional accuracy

Abdulridha HInd Hadi, Obaeed Nareen Hafidh, Jaber Adil Shbeeb

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 4

50--64

EN

Fused Deposition Modeling (FDM) is a type of additive manufacturing (AM) that has received significant interest from researchers and industries due to its flexibility in design, efficient use of materials, and affordable costs. In this paper, the main objective is to investigate the influences of FDM process parameters on the flexural properties as well as the accuracy of the final part made from polyethylene terephthalate glycol (PETG) material, which is widely used for 3D printing due to its strength and ease of use. A response surface methodology (RSM) approach based on a Box–Behnken design was employed, with three key process parameters: infill line distance, wall line count, and build plate temperature. The analysis of the data indicated that all three parameters affected the inherent characteristics of the printed parts, including mechanical and dimensional characteristics of the printed parts. The build plate temperature was identified as the most significant parameter, contributing 53% of the variability in the flexural strength of the printed specimens and 39.7% to deviation in the dimensional accuracy of the specimens, as indicated by the analysis of variance (ANOVA). A comparison between the predicted values of the model and the corresponding experimental results showed the suitability of the developed model with high accuracy. The maximum percentage errors observed in this study were 3.4% for the flexural strength and 7.5% for the dimension accuracy, establishing the efficacy of the optimization technique. These outcomes are meaningful to understand the influences of the process parameters on material response and offer a systematic approach to develop structurally enhanced PETG parts with improved mechanical characteristics and geometric dimensions.

8

Evaluation of tensile strength and flexural strength of GFRP composites in different types of matrix polymers

Sulistyo A. B., Wirawan W. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2024

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Vol. 123, nr 2

49--57

EN

Purpose: Resin selection has a crucial role in determining the properties and performance of GFRP composites; this study aims to investigate the effects of different resin types, specifically epoxy, bisphenol, ripoxy, and polyester, on the mechanical strength of GFRP composites. Design/methodology/approach: The composites were fabricated using the conventional method of hand lay-up technique with a fiber to matrix ratio of 60:40 wt%. The glass fibre laminate arrangement consists of 4 layers, two layers of Woven Roving Mat (WRM) fibres (0°/90°) and 2 layers on the outer side of the Chopped Strand Mat (CSM). The composite specimens were molded using the ASTM D-838 tensile test standard and ASTM D-790 for the bending test. Findings: The research results found that the maximum tensile strength was obtained by GFRP composite with ripoxy matrix type of 181.6 MPa, strain of 0.028%, and flexural strength of 1387 MPa. Composites using polyester matrices can generally be classified as splitting in multiple areas where failure occurs in various areas, but the composite has very high strength. Research limitations/implications: Material experiments conducted on a scientific laboratory scale may not fully reflect the behaviour of composites in actual conditions. Furthermore, aspects such as environmental influences, sustained stresses, or fatigue effects may need to be considered in further research. This evaluation also does not consider the effects of long-term exposures or ageing on the mechanical properties of GFRP composites. Investigating the behaviour of materials over long periods can provide important insights into their durability and reliability in practical applications. Practical implications: In GFRP composites, the application of resin to the fibres is critical. The performance and mechanical characteristics of GFRP composites are largely determined by the polymer matrix. Composites with epoxy, polyester, or bisphenol matrices can be compared to composites with the most equivalent tensile strength values, but composites with ripoxy matrices can be suggested. However, the GFRP composite with bisphenol matrix has an excellent bending strength value. As a result, numerous applications exist for implementing matrix selection in producing GFRP composites. Originality/value: The reliability of the tensile properties of GFRP composites was obtained using the ripoxy matrix type. Furthermore, the reliability of the flexural properties of the composites was obtained using the bisphenol matrix type.

9

Experimental Investigation on the Effect of Graphene Addition on Mechanical Properties of Al8011-T6 Based Fiber Metal Laminate

Zakaulla Mohamed

Archives of Metallurgy and Materials

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2024

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Vol. 69, iss. 2

787--794

EN

In the present study, the tensile and flexural properties of lightweight fiber metal laminates composed of Al8011-T6 and carbon fiber/epoxy resin filled with varying weight percentages of graphene (0.0, 0.3, 0.6, 0.9, and 1.2 wt%) were examined under quasi-static loadings for automobile applications. Fibre-metal laminates having different stacking sequences of the same layer thickness are manufactured using the hand layup process. Surface treatment was performed on Al8011-T6 sheet in order to get good adhesion between aluminium and epoxy. With the optimum content of 0.6 and 0.9 wt% of graphene, the tensile and flexural strengths were improved by 15% and 25%, respectively, compared to aluminium fiber metal laminates without graphene for 0/0 fiber layup orientation.

10

Four‑point bending test of high‑early‑strength high ductility concrete (HES‑HDC): early mechanical behavior and toughness evaluation

Yang Jiasheng, Deng Mingke, Zhang Yangxi, Fan Hongkan

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 1

art. no. e36, 2024

EN

To investigate the early mechanical response of high-early-strength high ductility concrete (HES-HDC), a four-point bending test was conducted. The effects of fiber type, fiber content, curing age, sand-binder ratio (s/b), and hydroxypropyl methyl-cellulose (HPMC) content on the crack pattern, load–deflection curve, flexural strength, and deflection of HES-HDC were studied. Based on the test results, a flexural toughness evaluation method suitable for the characteristics of HDC was proposed. The results showed that under flexural load, the load–deflection curve of HES-HDC exhibited a deflection-hardening response, with multiple cracks developed during the failure process. The flexural strength of HES-HDC reaches more than 5 MPa in 2 h, meeting the requirements for open traffic. Fiber type, fiber content, and curing age had a significant impact on the cracking behavior, deflection-hardening response, and flexural strength of HES-HDC. The higher the fiber pullout proportion and bridging stress during the crack-bridging was, the higher the deflection and energy absorption of HES-HDC exhibited. The existing flexural toughness evaluation methods were not applicable for HDC assessment due to their inability to consider the influence of different fiber types on the deflection-hardening response of HDC. A flexural toughness index in the form of energy ratio and a flexural strength coefficient in the form of strength ratio was proposed, which can effectively evaluate the flexural toughness of the HES-HDC beam during its whole loading process. This method took into account the large deformation of HDC and eliminated the influence of specimen size by using dimensionless forms.

11

Optimizing Fused Deposition Modelling Process Parameters for Medical Grade Polymethylmethacrylate Flexural Strength

Obaeed Nareen Hafidh, Hamdan Wisam K.

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no. 1

349--359

EN

The production of functional parts, including those employed by the biomedical industry has been achieved a promising candidate in Fused Deposition Modelling (FDM). The essential properties of these biomedical parts which manufactured by additive manufacturing as compared to some other conventional manufacturing processes depend on structural and process parameters rather than material properties alone. Regarding to the evaluation the flexural strength of medical-grade, Polymethylmethacrylate PMMA has been received relatively very little investigation to date. PMMA is a biocompatible filament that be used in manufacturing of patient-specific implants such as dental prosthesis and orthopaedic implants. The proposed work explores the effect of three process parameters that vary with respect of three levels on the flexural strength. These levels can be specified by layer height (120, 200, 280 µm), infill density (40, 65, 90 %) and skewing angle (0º, 45º, 90º) on the flexural strength of medical-grade PMMA. Maximum and minimum flexural strength that be obtained in this work about (93 and 57 MPa) respectively. The analysis of variance (ANOVA) results shows that the most effective factor is the layer height followed by infill density. The flexural strength rises significantly with decreases layer height and the skewing angle is in zero direction. The process parameters have been optimized through utilizing of genetic algorithms. The optimal results that emerged based on genetic algorithm technique are approximately (276 μm) as layer height, (46 %) infill density and skewing angle (89 º) which maximize the flexural strength to (97 MPa) at crossover for ten generation.

12

Effect of thermoplastic waste from production on the strength of cement mortars

Pietrzak Alina

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2023

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nr 75 (147)

42--48

EN

This paper presents study results on the effect of the addition of polymeric waste on selected mechanical properties (flexural and compressive strength) of cementitious composites with a special emphasis on cement mortars. This research focuses on cement mortars, commonly used in construction applications such as seaports and quays. Here, post-production waste from the production of automobile floor mats is ground to a fraction of 0–2 mm and used in the amounts of 5%, 7.5%, and 10% by weight of cement as an additive or substitute for sand. All the presented tests are conducted in accordance with PN-EN 197-1. The purpose of these tests is to determine the possibility of using thermoplastic waste as an aggregate substitute or additive in cement mortars. The conducted research confirmed the possibility of using the mentioned waste in cement mortar production technology in the amount of 5% as a substitute for sand.

13

Paper-sawdust composites: fabrication and comparison in terms of heat transfer and strength properties

Robert Ubong Williams, Ekong Sylvester Andrew, Akpan Samuel Sunday, Etuk Sunday Edet, Inyang Namdie Joseph, Agbasi Okechukwu Ebuka

Structure and Environment

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2023

|

Vol. 15, no. 1

38--49

EN

This study was designed to examine the feasibility of recycling cassava effluent, sawdust, and unused paper products to enhance their utilization for beneficial purpose. Waste newspaper paste (WNP), Waste writing-paper paste (WWP), and Waste carton paper paste (WCP) were prepared and then used separately to similarly fabricate composite panels with Sawdust particle (SDP) proportioned at 0%, 25%, 50%, 75%, and 100% by weight. The binder used was cassava starch slurry prepared from the effluent. Bulk density, water absorption, thermal conductivity, specific heat capacity, thermal diffusivity, nailability, and flexural strength were determined for the developed samples. From the results obtained, the samples were found to be light-weight and their thermal insulation performance improved with increasing proportions of the SDP. Though samples containing the WCP exhibited the best satisfactory performance, it was found that all the studied samples could perform more effectively and efficiently as ceilings compared to some of those reported in the literature. From scientific-economic viewpoint, valorizing the above-mentioned wastes as described in this paper could help to protect the environment and also yield value-added insulation ceilings for enhancement of sustainable building construction especially in tropical areas.

PL

Celem pracy było określenie możliwości recyklingu ścieków z manioku, trocin i odpadowych materiałów papierniczych w celu ich szerszego wykorzystania. Nitki z makulatury gazetowej (WNP), nitki z makulatury z papieru do pisania (WWP) i nitki z makulatury z kartonu (WCP) zostały przygotowane, a następnie użyte osobno do wytworzenia paneli kompozytowych z dodatkiem trocin (SDP) przy udziale masowym 0%, 25%, 50 %, 75% i 100%. Zastosowanym spoiwem była przygotowana z odcieku zawiesina skrobi z manioku. Dla przygotowanych próbek określono gęstość nasypową, nasiąkliwość, przewodność cieplną, ciepło właściwe, dyfuzyjność cieplną, zdolność do wbijania gwoździ i wytrzymałość na zginanie. Na podstawie uzyskanych wyników stwierdzono, że próbki miały małą gęstość objętościową, a ich właściwości termoizolacyjne poprawiały się wraz ze wzrostem udziału trocin (SDP). Chociaż próbki zawierające WCP wykazywały najlepsze właściwości, stwierdzono, że z wszystkich badanych próbek można wytworzyć sufity o lepszych właściwościach w porównaniu z podobnymi opisanymi w literaturze. Z naukowo-ekonomicznego punktu widzenia zastosowanie wyżej wymienionych odpadów, jak opisano w tym artykule, może pomóc w ochronie środowiska, a także w uzyskaniu bardziej ciepłochronnych stropów, a co za tym idzie przyczyni się do rozwoju bardziej zrównoważonego budownictwa, zwłaszcza w obszarach tropikalnych.

14

Effects of incorporating granite powder in the mechanical properties of concrete

Muñoz Pérez Socrates Pedro, Atoche Zamora Jorge Jr.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2023

|

Vol. 32, No. 1

18--33

EN

This study analyzes the effects of the incorporation of the granite powder (GP) as a partial replacement of the sand in the concrete in percentages of 10%, 15%, 20% and 30% to carry out a mix design of 210 kg·cm–2. Seeking to find an optimal proportion to increase its mechanical properties where the geotechnical characteristics of the aggregates were identified, workability, temperature, beams and concrete specimens were elaborated. The results of bending and compression tests were compared after 7, 14 and 28 days from setting between the standard concrete and the concrete incorporated with the GP. It is concluded that the optimal result was at 20% GP with 268.6 kg·cm–2, where the compressive strength increases by 13%, while its flexural property rupture modulus of 35 kg·cm–2 and workability are in an optimal range according to the stipulated parameters, thus allowing an important application for this waste in the construction industry, therefore contributing to recycling, environmental quality and the development of the usage of new materials.

15

Ocena wpływu ekstremalnych temperatur utwardzania wyrobów do konstrukcyjnego łączenia materiałów na ich wybrane właściwości użytkowe

Wojnowski Damian, Bardan Magdalena

Przegląd Budowlany

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2023

|

R. 94, nr 7-8

65--69

PL

Celem eksperymentu była ocena wpływu temperatury utwardzania na wybrane właściwości użytkowe wyrobów do łączeń konstrukcyjnych. Do badań wytypowano trzy kleje epoksydowe przeznaczone - w ramach naprawy konstrukcji betonowych - do przyklejania materiałów, takich jak np. maty z włókien węglowych, szklanych i aramidowych. Substraty, z których składają się poszczególne kleje, jak również przygotowane obiekty badawcze, kondycjonowano w warunkach laboratoryjnych oraz ekstremalnych temperaturach utwardzania, wytypowanych do projektu w oparciu o informacje znajdujących się w kartach technicznych wyrobów. Jako temperatury ekstremalne przyjęto maksymalną 35˚C i minimalną 10˚C wartość deklarowaną wspólną dla wytypowanych klejów. Przeprowadzono badania, których wyniki stanowią podstawowe kryterium oceny jakości połączeń klejowych, takie jak: wytrzymałość na ścinanie (przy różnych wartościach kąta nachylenia złącza), wytrzymałość na ściskanie i zginanie. Dodatkowo wykonano badanie przyczepności betonu starego do betonu starego, które pozwoliło określić, jaki wpływ ma temperatura utwardzania na połączenie kleju i betonu. Analiza uzyskanych wyników wykazała wpływ temperatury utwardzania wyrobów do łączeń konstrukcyjnych na ich wybrane właściwości użytkowe. Większy wpływ na obniżenie poziomu uzyskanych parametrów ma spadek temperatury utwardzania klejów do łączenia konstrukcyjnego do 10°C.

EN

The aim of the experiment was to evaluate the influence of the hardening temperature on selected performance properties of products for construction joints. Three epoxy adhesives were selected for the tests, intended - as part of the repair of concrete structures - for gluing materials such as carbon, glass and aramid fiber mats. The substrates, which make up the individual adhesives, as well as the prepared research objects, were conditioned in laboratory conditions and extreme hardening temperatures, selected for the project based on the information contained in the technical data sheets of the products. The maximum 35˚C and minimum 10˚C declared values shared by the selected adhesives were adopted as extreme temperatures. Tests were carried out, the results of which constitute the basic criterion for assessing the quality of adhesive joints, such as: shear strength (at different values of the angle of inclination of the joint), compressive and bending strength. In addition, the adhesion test of the old concrete to the old concrete was performed, which allowed to determine the influence of the hardening temperature on the bonding of the adhesive and concrete. The analysis of the obtained results showed the influence of the hardening temperature of products for construction joints on their selected performance properties. The decrease in the curing temperature of structural adhesives to 10°C has a greater impact on the reduction of the obtained parameters.

16

Physicochemical and Mechanical Characterization of Ceramic Materials from Meknes Region (Morocco)

Mesrar Hamza, Mesrar Laila, Jabrane Raouf

Journal of Ecological Engineering

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2023

|

Vol. 24, nr 8

183--197

EN

This scientific paper presents a comprehensive study of the physical and chemical properties of a clay sample collected from Meknes region of Morocco. X-ray diffraction analysis revealed the presence of kaolinite, muscovite, and quartz minerals in the clay sample. X-ray fluorescence analysis showed that the sample contained a significant amount of aluminum and silica. The Atterberg limit test indicated that the clay has a high plasticity index and is classified as a clay of low to medium plasticity. The ATG_DSC analysis revealed that the sample underwent multiple endothermic reactions, including dehydration, dehydroxylation, and decarbonation, at different temperature ranges. Shrinkage and weight loss experiments showed that the clay exhibited high shrinkage and weight loss upon drying. SEM-EDX analysis provided information on the microstructure and elemental composition of the clay sample. The water absorption test revealed that the clay has a low water absorption capacity. The three-point flexural test showed that the clay bricks had high flexural strength, which makes it suitable for use in high-stress applications. Overall, the results suggest that the clay sample can be used in a variety of applications, including building materials, ceramics, and other industrial uses.

17

Mechanical Properties of Polypropylene Composites with Different Reinforced Natural Fibers – A Comparative Study

Simamora Pintor, Simanjuntak Josua, Sinulingga Karya, Laksono Andromeda Dwi

Journal of Ecological Engineering

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2023

|

Vol. 24, nr 7

311--317

EN

Developing environmentally friendly and recyclable natural fiber-reinforced polymer composites has recently attracted researchers’ attention and interest. Herein, a comparative study was conducted to compare the mechanical properties of polypropylene (PP) composites with different natural fiber reinforcement, including palm fiber (Arenga pinnata), rice straw (Oryza sativa), coconut husk (Cocos mucifera), old world forked fern leaves (dicranopteris linearis), and snake plant (Sansevieria trifasciata). This study aimed to compare the influence of the five natural fiber materials on the tensile strength and flexural strength of PP composites. The natural fibers were chemically treated with a 5% NaOH solution for 2.5 hours. In the preparation of composites, polypropylene as the matrix is heated to 300 °C and mixed randomly with natural fibers. The test results indicate that the composite with the highest tensile strength (38% higher than the lowest) and flexural strength (102% higher than the lowest) is obtained using the PP composite with reinforced rice straw fiber. In contrast, the PP composites with palm fiber have the lowest tensile strength (72% from the highest tensile strength) and the lowest flexural strength (UFSmin) (62% from the highest flexural strength) corresponds to the PP composites with coconut fiber. This study revealed that the flexural strength of all composite samples was greater than that of pure PP.

18

Effect of Potable, Acidic and Alkaline Water Curing on Flexure Strength of Strengthened and Unstrengthen Reinforced Concrete Beams

Barkale Akshay D., Thakare Sunil B.

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 2

153--161

EN

The rapid growing population has resulted into the need of additional capacities of existing infrastructure facilities, commercial buildings etc. Also, the revisions of codal provisions has made many existing structures fall out of the safety criteria mandated by these provisions. In such scenario, from environmental point of view it is always better to strengthen the existing structure than demolish it and cause pollution. Such structures are made to withstand greater load than their capacity by means of supplementary systems also known as strengthening schemes. Recently, Fiber Reinforced Polymer (FRP) is in wide use in strengthening aspect due to its various advantages. Also, Potable Water is a scarcest commodity these days. Its significance in construction industry have been vital. Concrete and water being the most utilized construction materials, this paper examines the effect of different pH water levels on flexure capacity of concrete beams with and without the strengthening system. Eighteen numbers of concrete beams with conventional reinforcement are casted with size of 500x100x100 mm3. These beams are divided into six categories so that each category has three number of beams. The beams are categorized based on the FRP application and pH value of curing solution. Three types of water is used with pH in the range of 4 to 5, pH of 7.5 and pH in the range 9 to 10. Single layer of Glass Fiber Reinforced Polymer (GFRP) fabric sheet is used for flexure strength enhancement. All beams are tested using flexural test till failure. Salient points viz. load and deflection at which first crack, service and failure. These points are noted for each beam and average of three beams of a group is presented as final reading. Suitable conclusions are drawn from these test results.

19

Effect of fiber content on tensile and flexural strength of water lily fiber reinforced polyester resin composite

Mesfin Solomon, Rengiah Robinson Gnanadurai, Shiferaw Melese, Guadie Tesfa

Composites Theory and Practice

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2023

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R. 23, nr 3

113--117

EN

Ethiopia has abundant invasive aquatic plants like water hyacinth and water lily. Large masses of these invasive plants have a negative impact on the country’s water bodies, specifically at Lake Tana in Ethiopia, by infesting and deteriorating water quality and reducing the quantity of water. In this research work, an attempt was made to fabricate a natural fiber reinforced composite in which water lily fiber was used as the reinforcing material in a polyester resin matrix. Chopped water lily fiber reinforced polyester resin composites were prepared by varying the fiber content - 20, 40 and 60 wt.%. Mechanical properties such as tensile strength and flexural strength were tested as per ASTM standards to evaluate the influence of the fiber contents. The experimental results show that an increase in the fiber content enhanced the mechanical properties of the water lily fiber reinforced polyester composite. It was found that the composite with 40 wt.% fiber exhibited superior strength which could be suitably used for different applications.

20

Badanie wpływu uszkodzeń powstałych w badaniu wytrzymałości na zginanie na wytrzymałość na ściskanie materiałów budowlanych

Hafçı Alkan

Cement Wapno Beton

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2023

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R. 28, nr 4

268--282

PL

Beton, czyli główny materiał sektora budowlanego, był przedmiotem wielu badań naukowych przez dziesięciolecia. W wyniku tych badań uzyskano nowe informacje naukowe na temat słabych punktów materiałów cementowych, szczególnie betonu, ich zachowania pod obciążeniem itp. W świetle tych informacji zaleca się, aby niektóre metody badawcze określone w normach międzynarodowych zostały zrewidowane. W niniejszym badaniu zbadano wpływ uszkodzeń spowodowanych przez badanie wytrzymałości na zginanie przeprowadzane na próbkach przygotowanych z beleczek z zaprawy o wymiarach 160 mm x 40 mm x 40 mm w ramach norm EN 13813, EN 13888, EN 13279-1, EN 197-1, TS 13566 i TS 13687, na wyniki badania wytrzymałości na ściskanie przeprowadzonego na złamanych próbkach. W końcowej analizie zaproponowano pewne sugestie dotyczące ulepszenia metody badawczej.

EN

Concrete, the principal material of the construction sector, has been the subject of many scientific researches for decades. As a result of these investigations, new scientific information has been obtained on the weak points of cement-based products, especially concrete, their behaviour under load, etc. In light of this information, it is recommended that some test methods specified in international standards be revised. In this study, the effect of damage caused by flexural strength test performed on samples prepared with mortar prisms, of dimensions 160 mm x 40 mm x 40 mm within the scope of EN 13813, EN 13888, EN 13279-1, EN 197-1, TS 13566 and TS 13687 standards, on the results of compressive strength test performed on the broken samples was investigated. In the final analysis, some improvement suggestions have been made in the test methods in question.