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Mechanical properties were evaluated for bio-natural fiber-reinforced epoxy hybrid composites made with varying amounts of jute, banana stem leaves (BSL), and tamarind shell powder (TSP). Each composite design had varying weight percentages of jute and BSL (5 to 25%) and a consistent mix of TSP (10%) and epoxy resin (60%). The tensile strength, flexural strength, interlaminar shear strength (ILSS), impact strength, hardness, and water absorption were examined. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to investigate chemical bonding and morphology. The findings indicated a relationship between fiber and filler content and mechanical properties of composites, with 20% jute fiber content resulting in the highest performance. The tensile strength of the composite increased by 24.6%, rising from 32.4 MPa for the 5% jute and 25% banana stem leaves (5J25BSL) composite to 40.4 MPa for the 20% jute and 10% banana stem leaves (20J10BSL) composite. Similarly, the flexural strength saw a 27.9% improvement, increasing from 67.2 MPa in the 5J25BSL composite to 86.0 MPa in the 20J10BSL composite. The impact strength also experienced a notable increase of 39.1%, moving from 2.56 J for the 5J25BSL composite to 3.56 J for the 20J10BSL composite. These results highlight significant improvements in all three properties, as the proportion of jute in the composite increased and the proportion of banana stem leaves decreased. This research influences material selection for engineering applications and informs the development of specialized composite materials. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the material properties of polymer-infiltrated zinc oxide networks (PICN) and the effect of using a phosphate monomer-containing primer applied before polymer infiltration. A total of 148 ZnO-network (zinc oxide) specimens were produced: n = 74 were treated with a primer before polymer infiltration and light curing, while the remaining specimens were untreated. Each group was divided into two subgroups (n = 37) based on the infiltrating polymer: UDMA (aliphatic urethane-dimethacrylates)-TEGDMA (triethylene glycol-dimethacrylate) or BisGMA (bisphenol A-glycidyl-methacrylate)-TEGDMA. Additionally, n = 7 specimens of each polymer type were prepared for comparison. Then, biaxial flexural strength was measured before and after 150 days of water storage at 37 °C, including 37,500 thermal cycles (5 °C to 55 °C). The Vickers hardness, surface roughness, and water absorption at 37 °C were also tested. The initial biaxial flexural strength was reduced in the ZnO network specimens compared to in the pure polymers. Primer application improved the flexural strength, though the strength of BisGMA-TEGDMA significantly decreased after water storage. The ZnO network increased hardness, and the polymer-infiltrated networks showed higher roughness post-grinding and absorbed less water than the pure polymer groups. The ZnO networks did not improve the flexural strength over that of the pure polymers. However, the primer's positive impact and the network's long-term stability suggest potential if the network structure can be modified to contain thicker, more stable branches. [ABSTRACT FROM AUTHOR]

This study examines the effects of varying ultraviolet (UV) exposure times on the properties of UDMA/TEG-DMA composite resins, focusing on degree of conversion, surface morphology, water absorption, shrinkage, hardness, and flexural strength. Composite resin samples were exposed to UV light for 30, 60, 90, and 120 min. The degree of conversion was assessed using Fourier Transform Infrared Spectroscopy (FTIR). Surface morphology was analyzed via Scanning Electron Microscopy (SEM). Water absorption and shrinkage were measured following standard procedures, while mechanical properties, including hardness and flexural strength, were evaluated using a Vickers hardness tester and a 3-point bending test, respectively. The results indicate that a UV exposure time of 90 min optimizes the composite resin properties, achieving the highest degree of conversion at 77 %, optimal surface morphology, minimal water absorption and shrinkage, and superior mechanical properties, including maximum flexural strength and hardness. In contrast, both shorter and longer UV exposure times detrimentally affected these properties, with prolonged exposure causing thermal degradation and reduced performance. This research underscores the importance of precise UV curing time control to enhance the performance and durability of UDMA/TEG-DMA composite resins, providing valuable insights and practical guidelines for their application in dental and industrial fields. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ceramics / Taoci Xuebao is the property of Journal of Ceramics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the current research, tensile, flexural, and compression were done, as well as the effect of water absorption on dimensional stability, to study the effect of adding different weight fractions of Macadamia nutshell about (10, 20, 30, and 40 wt %) to Polyvinyl Butyral composites. Different average grain sizes of Macadamia nutshell (75 µm, 150 µm, and 300 µm) were used. In addition, both FTIR analysis and morphological observation of composites were conducted. Findings reveal that M7501 (10% filler, 75 µm) consistently achieves the highest mechanical properties, including tensile strength (35% higher), Young's modulus (15% higher), toughness (40% greater), tensile strain (25% greater), flexural strength (29% higher), and compressive strength (20% higher) compared to M7504 (40% filler). Conversely, composites with larger particle sizes and higher filler content, such as M3004 and M1504, exhibited significant reductions in mechanical properties, with up to 43% lower flexural strength and 41.7% lower compressive strength compared to their counterparts with lower filler content. Higher filler contents exacerbated this issue by increasing the likelihood of particle clustering, which creates weak points and voids that compromise the structural integrity of the composite. Additionally, larger particle sizes (150 µm and 300 µm) showed more pronounced agglomeration and void formation compared to smaller particles (75 µm), further highlighting the challenges in achieving a homogeneous composite structure with larger fillers. SEM investigation demonstrated that increasing filler amounts led to noticeable particle agglomeration, aggregation and void formation, negatively impacts the composites, leading to weaker mechanical properties. [ABSTRACT FROM AUTHOR]

This paper investigates the effects on the physical and mechanical properties and microstructure of lime-hemp concrete (LHC) materials at different binder mass ratios. A mixture of three cementitious materials, slaked lime, cement, and coal gangue powder, was used as binder, and hemp shives were used as concrete aggregate, and five test groups were designed, i.e., binder/hemp shives (B/H) mass ratios of 1.2, 1.4, 1.6, 1.8, and 2.0. The physical properties of LHC, including density, drying rate, water absorption, thermal conductivity coefficients, and mechanical properties (compressive strength and flexural strength) with different binder ratios were investigated. In addition, the microstructural properties of 56d LHC were investigated by SEM, XRD, and TG-DTG micro-scale analysis methods. The results showed that with the increase in binder content, the drying speed of LHC became faster, the thermal conductivity coefficients, compressive strength, and flexural strength increased, and the water absorption was just the opposite. With a fit ratio of 2.0, the strength is the greatest and the toughness is the best; with a fit ratio of 1.2, the thermal conductivity coefficient is the smallest and the insulation effect is the best. In addition, the hydration of the binder produced different forms of hydration products (CaCO3 and C-S-H), and the hydration products increased in quantity with the increase of the binder, resulting in stronger CaCO3 and C-S-H diffraction peaks. The hydration products produce a better bond with the rough cannabis particle surface, filling the internal voids of the LHC, improving the density of the material, and enhancing the mechanical properties of the material. [ABSTRACT FROM AUTHOR]

In polymer matrix composites (PMCs), reinforced lignocellulosic fibres are one of the excellent endeavours; doing so eliminates the need for the more commonplace synthetic fibres. In this respect, the fibres from Enset ventricosum (EV), one of the underutilized which have not been studied extensively, were focused to carry out an investigation on PMCs applications using the particles of Limonia acidissima fruit shell powder (LASP) as reinforcing agent. The study set out to evaluate the adeptness of altered LASP and EV plant fibres by 4% NaOH treatment. The results from morphological, physicochemical, XRD, FTIR, and thermal aspects of alkali-treated samples of LASP and EV fibres revealed that the alkali treatment significantly improved the compatibility of biomaterial' property to utilize the natural fillers in the epoxy–EV fibre composites. The first-degree polynomial model was fitted using the response surface analysis to optimize the impact energy, water absorption, tensile, and flexural strength of reinforced fibre with respect to composition and fibre length. Using RSM numerical model, aforementioned properties were analysed to develop the ideal epoxy–EV fibre composite for attaining a minimal water absorption, a high tensile modulus, flexural strength, and impact energy. Accordingly, 3 mm of fibre length reinforcement with 38.3 wt % of biomaterials loading reinforcement was found to be optimized for idealistic epoxy–EV fibre composite. [ABSTRACT FROM AUTHOR]

As a degradable polymer material, polybutylene succinate (PBS) has the disadvantages of high cost, slow crystallization rate, and low strength modulus. Reinforcing modification with plant fibers is a popular method. A unique three-dimensional network structure was found in luffa fiber (LF). Compared to other plant fibers, this fiber has excellent mechanical strength due to its unique three-dimensional structure. Its structure allows it to maintain the integrity of the reinforcement phase in the polymer aggregate, overcoming the dispersion and defects of short fiber reinforcement. Herein, the LF was treated with alkali treatment and silanated with three coupling agents and pre-impregnation methods to improve interfacial properties with the PBS matrix. Then it was laminated with polybutylene succinate to prepare a PBS/LF composite board with three layers of LF. The performance of the composite material using the KH550 coupling agent was improved the most. The tensile strength and modulus of the material were increased by 24.9% and 82.9%, respectively, the flexural strength and modulus were increased by 21.7% and 18.5%, and the impact strength was increased by 12.5%. The water absorption weight gain rate is also the lowest, about 3.5%. For the LF-reinforced PBS, the preparation method is simple, and the reinforcement effect is better, that the cost was effectively reduced, and the application field of the PBS green material was expanded. A new possibility for the development of green degradable polymer composites was provided. [ABSTRACT FROM AUTHOR]

Fiber-reinforced cement matrix composites (CMCs) have gained significant attention due to their ability to enhance material properties for use in demanding environments. This study investigated the workability and mechanical properties of polyvinyl alcohol (PVA) fiber-reinforced CMCs, focusing on compressive strength, split tensile strength, and flexural strength. It also assessed water absorption capacity through immersive water absorption tests using cubes and capillary water absorption tests using cylinders, alongside bulk density measurements for both shapes. The results indicated that the dosage of PVA fibers significantly influences the workability of CMCs, while the water-to-binder ratio has a minimal effect. Increasing the dosage of PVA fibers in CMCs from 0.5 vol.% to 1 vol.% led to a decrease in several properties: compressive strength decreased by 13.38%, split tensile strength by 21.05%, flexural strength by 9.23%, bulk density of cube samples by 4.14%, and bulk density of cylindrical sample by 6.36%. Conversely, both immersive water absorption and capillary water absorption increased, rising by 10.87% and 77.71%, respectively. Compressive strength was found to increase with the bulk density of the cubes and to decrease with rising immersive water absorption. Similarly, split tensile strength increased with the bulk density of the cylinders and decreased as capillary water absorption increased. Strong correlations were observed among three key pairwise combinations: the bulk density of cubes and immersive water absorption (R2 = 94%), compressive strength and bulk density of cubes (R2 = 96%), and compressive strength and immersive water absorption (R2 = 92%). Furthermore, the analysis and comparison of carbon fiber-reinforced and PVA fiber-reinforced CMCs will provide important references for the field, especially in cases where material availability or cost varies. [ABSTRACT FROM AUTHOR]

Copyright of Low-Carbon Materials & Green Construction is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recently, bio-composites have attracted much attention due to their potential applications in various industries. The most notable benefits are the product's low cost, biodegradability, lightweight, availability, and ability to solve environmental issues. The present research utilizes ash gourd (Benincasa hispida) peel, a food waste, as a filler material to produce epoxy (EP) composites. The effect of ash gourd peel particle percentage (ranging from 0 to 25 wt.%) was studied on the developed composites' mechanical and thermal properties and water absorption behavior. The maximum tensile strength, flexural strength, and shore D hardness were 47.52 MPa, 2409.17 MPa, and 79.6respectively, when the ash gourd peel was 5% by weight in the composite. It was observed that the mechanical characteristics of manufactured bio-composites are negatively affected by the high concentration of ash gourd peel particles in the epoxy matrix. Also, increasing ash gourd peel particle fraction increases the water absorption of composites when immersed in distilled, sea, and tap water. The composite with 5% filler by weight absorbs water at a minimal rate when immersed in seawater. Thermogravimetric analysis was conducted to investigate the newly developed composite's thermal behavior. In addition, a morphological examination of the fractured surfaces was carried out with assistance from a scanning electron microscope. The work presents ash gourd peel particles as the potential alternative to be used as filler in composites. [ABSTRACT FROM AUTHOR]

The mechanical qualities of natural fiber (NF) -based polymer composites are superior, making them advantageous and these composites are environmentally beneficial. The current investigation involved the fabrication of hybrid composites using Calotropis gigantea (CGF) and Abaca Fiber (AF) as reinforcements in epoxy matrix. The hand layup technique was employed for the fabricating process. Subsequently, the composites were investigated and analysed for their water absorption rate, tribological performance, and mechanical properties. This study aims to uncover a noteworthy combination of NF reinforced polymer composites that can be utilized in commercial Engineering applications. The mechanical properties were examined by measuring their hardness, impact resistance, flexural strength (FS), Compressive strength (CS), and tensile strength (TS). Furthermore, the broken surfaces of tensile sample were inspected utilizing a scanning electron microscope. Composite specimens were immensed in distilled water and their water penetration percentages were measured to ascertain their water absorption (WA) properties. The tribological performance was analysed utilizing a pin-on-disc equipment to assess the specific wear rate and coefficient of friction. The outcomes demonstrated that the hybrid composites surpassed the single-fiber composites in all variations. Sample G exhibited superior properties in all combinations, with a TS of 36.19 MPa and tensile modulus of 328.95 MPa. Additionally, it shows that higher flexural strength of 43.85 MPa and flexural modulus values of 350.84 MPa. Furthermore, it demonstrated higher Compressive strength of 94.45 MPa and modulus values of 576.93 MPa. Moreover, it exhibited a higher impact value of 53.88 kJ/m2 and higher hardness value of 44.07 HV. This material is well-suited for non-structural uses in electronics and electrical insulating boards and components, as the results show that a combination of CGF and AF fibers with an epoxy matrix improves mechanical qualities. [ABSTRACT FROM AUTHOR]

Railway passing traffic, speed, and load have significantly increased over the years, prompting industry stakeholders and researchers to seek an alternative sleeper material that can demonstrate its ability to potentially possess higher in-service bending resistance and be environmentally friendly and durable. To address these needs and due to environmental concerns, kenaf-reinforced polyamide has become of great importance. However, they could not be applied as railway track components because of the non-availability of their performance in this regard. In bridging this gap, this paper focused on fabricating and characterising six different formulations of treated kenaf fibre (TKF, 0-50% at 10% loading interval) reinforced polyamide biocomposites for railway sleeper applications. The result showed that the incorporation of TKF influenced the behaviour of the polyamide with respect to its water absorption, load-carrying capacity, and thermal stability. The result further demonstrated that the load-bearing capacity peaked at TKF 40 wt.%, surpassing conventional wooden and concrete sleepers. However, its water absorption (64-days saturation) behaviour increased significantly between 11%-21% as TKF rose from 10-50 wt.%, as expected due to TKF hydrophilic characteristics. On the other hand, TKF thermal stability was hampered beyond approximately 220°C for all TKF percentages. Kenaf fibre-reinforced polyamide biocomposites have demonstrated their potential for railway sleeper applications as their load-bearing capacity exceeded the minimum recommended AREMA specifications. Despite the milestone achieved, water absorption of kenaf fibre remained high. The development of sustainable and effective materials to meet the changing needs of contemporary railway infrastructure is greatly aided by the insights gained from this study. [ABSTRACT FROM AUTHOR]

Extensive research efforts have been undertaken in the past to utilize several kinds of recycled fine aggregates to produce environmentally friendly and more sustainable concrete. In Thailand, various types of bricks, including fired clay hollow, fired clay solid, and hydraulically pressed cement-clay bricks, are manufactured for constructing low-rise buildings. There is an urgent requirement to employ recycled fine aggregates made from these bricks to mitigate the disposal and demolition waste generated by the brick industry. At present, the utilization of waste bricks of Thailand's origin as fine aggregates in concrete is yet to be investigated. Three types of fine recycled brick aggregates were utilized to create sustainable concrete. The recycled fine brick aggregates were substituted for natural fine aggregates at proportions of 0%, 10%, and 20% to formulate the concrete mixes. Furthermore, three distinct types of tests—compression, splitting, and flexural tests—were conducted to evaluate the mechanical properties of the concrete. The compressive and splitting tensile strengths increased with the replacement ratio of recycled aggregates. Notably, up to 51% and 80% improvements in the compressive and splitting tensile strength were observed, corresponding to 20% replacement proportions, respectively. However, the flexural strengths exhibited were attributed to the type of waste brick, with a maximum improvement of up to 22%. Moreover, the water absorption tendency was reduced by incorporating recycled fine aggregates in concrete. The current work aimed only at examining the strengths of recycled brick aggregate concrete. Therefore, future works are recommended to investigate the complete stress vs. strain constitutive relationships of this concrete as well as its flowability. [ABSTRACT FROM AUTHOR]

Concrete, a globally used construction material, lacks tensile strength without reinforcement. Researchers explore novel materials to enhance reliability and sustainability. Notably, concrete contains significant carbon due to cement use. Recent research indicates jute fiber's (JF) potential to enhance concrete's mechanical strength and reduce carbon emissions. This study analyzes JF's application in mechanical properties and environmental impact, addressing a literature gap. Experiments added JF at varying percentages (0%, 0.10%, 0.25%, 0.50%, 0.75%) and conducted tests in fresh and hardened states (slump, CS, STS, FS, WA). Embodied carbon (EC) ratios were computed. Results show JF reduces environmental impact, with optimal proportions (e.g., 0.10% JF) enhancing CS, STS, and FS. Response Surface Methodology (RSM) created a model for JF effects. The study identifies potential benefits for advancing concrete through JF utilization. [ABSTRACT FROM AUTHOR]

This experimental study presents the influence of basalt fiber on the rheological and mechanical properties and the durability behavior of self-compacting concrete (SCC). In this study, a total of five self-compacting concrete mixtures were prepared: one as a control mix and the other mixes with 0.05%, 0.1%, 0.15%, and 0.2% basalt fibers. Slump flow and V-funnel flow tests were employed to assess the influence of basalt fibers on the rheological properties of fresh self-compacting concrete (SCC). Additionally, mechanical properties, including compressive strength, splitting tensile strength, and flexural strength, were analyzed. Furthermore, the mechanical properties were assessed following exposure to elevated temperatures (400 °C and 600 °C) as well as 100 and 200 freeze-thaw (F/T) cycles. Additionally, water absorption and ultrasonic pulse velocity tests were conducted on the SCC mixes after 28 days of curing. The results revealed that the addition of fiber has a significant effect on the rheological properties of fresh SCC mixtures. As the volume of fibers increases, the reduction in rheological properties increases. Basalt fiber had no effect on the compressive strength, while the splitting and flexural strength were significantly enhanced by 33% using basalt fiber. As temperatures and freezing-thawing cycles escalated, the mechanical properties of SCC exhibited a decline. Experimental findings indicated that elevating the temperature to 600 °C resulted in a decrease of over 20% in both the tensile and compressive strengths of SCC. Moreover, the results demonstrated that the incorporation of basalt fibers substantially enhanced the mechanical properties of SCC when subjected to high temperatures and freezing-thawing cycles. In addition, water absorption increased slightly by the incorporation of basalt fiber. [ABSTRACT FROM AUTHOR]

The current investigation is centred on the impact of inter-laminar fibre orientations on the physical and mechanical behaviour of lignocellulosic roselle fibre composites. For this research, the composites with 0°/90°, 0°/45° and ± 45° fibre orientations were developed via the hand layup method. All composites manufactured are of high quality and include fewer voids (1.28–3.30%). Results revealed that 0°/45° layered composite has better mechanical strengths. The bending and impact strength of the 0°/45° layered composite are 66.60 MPa and 14.01 kJ/m2, respectively. The flexural strength of 0°/45° layered composite is 17% higher than 0°/90° layered composite and 77% more than ± 45° layered composite. The impact strength of 0°/45° layered composite is 119% greater than 0°/90° layered composite and 55% higher than ± 45° layered composite. This material may be used for lightweight applications such as automotive door panels, automotive interiors, casings of electrical appliances, etc. [ABSTRACT FROM AUTHOR]

The global challenge faced due to the impact of the construction industry on climate change, along with the issues surrounding sustainable waste disposal, has necessitated various research on using waste products as eco-friendly alternatives in construction. In this study, the avoidance of waste disposal through landfills in Australia was encouraged by incorporating lime kiln dust (LKD) and tire rubber waste (TRW) into masonry mixes to manufacture green bricks. Furthermore, the investigations in this article highlight the use of mercury intrusion porosimetry (MIP) to determine the durability of the LKD-TRW bricks when exposed to freeze–thaw (F-T) cycles by examining the pore size distribution within the bricks. The LKD waste was blended with ground granulated blast furnace slag (GGBFS) at a 70:30 blending ratio and combined with the TRW in stepped increments of 5% from 0 to 20% to produce these eco-friendly bricks. The compressive strength (CS), flexural strength (FS), frost resistance (FR), pore size distribution according to mercury intrusion porosimetry (MIP), and the water absorption (WA) properties of the bricks were assessed. The CS and FS values at 28 days of curing were recorded as 6.17, 5.25, and 3.09 MPa and 2.52, 2, and 1.55 MPa for 0, 5, and 10% TRW contents, respectively. Durability assessments using the F-T test showed that the bricks produced with 0% TRW passed as frost-resistant bricks. Furthermore, the results from the MIP test showed a total pore volume of 0.033 mL/g at 3 µm pore size for the 0% TRW content, further confirming its durability. Hence, the 0% LKD-TRW bricks can be utilized in cold regions where temperatures can be as low as −43 °C without deteriorating. Lastly, WA values of 7.25, 11.76, and 14.96% were recorded for the bricks with 0, 5, and 10% TRW, respectively, after the 28-day curing period. From all of the results obtained from the laboratory investigations, the LKD-TRW bricks produced with up to 10% TRW were within the satisfactory engineering requirements for masonry units. [ABSTRACT FROM AUTHOR]

As key performance indicators, the water absorption and mechanical strength of ceramics are highly associated with sintering temperature. Lower sintering temperatures, although favorable for energy saving in ceramics production, normally render the densification degree and water absorption of as-prepared ceramics to largely decline and increase, respectively. In the present work, 0.5 wt.% MnO2, serving as an additive, was mixed with aluminosilicate ceramics using mechanical stirring at room temperature, achieving a flexural strength of 58.36 MPa and water absorption of 0.05% and lowering the sintering temperature by 50 °C concurrently. On the basis of the results of TG-DSC, XRD, MIP, and XPS, etc., we speculate that the MnO2 additive promoted the elimination of water vapor in the ceramic bodies, effectively suppressing the generation of pores in the sintering process and facilitating the densification of ceramics at a lower temperature. This is probably because the MnO2 transformed into a liquid phase in the sintering process flows into the gap between grains, which removed the gas inside pores and filled the pores, suppressing the generation of pores and the abnormal growth of grains. This study demonstrated a facile and economical method to reduce the porosity and enhance the densification degree in the practical production of aluminosilicate ceramics. [ABSTRACT FROM AUTHOR]

Concrete with no slump that is typically used for prefabrication is known as zero slump concrete (ZSC). ZSC is sensitive to mixture proportion. Since coarse aggregate makes up the majority of the concrete volume, recycling concrete aggregates will be a great choice for reducing the amount of concrete waste. Therefore, the purpose of this paper is to analyze the impact of using coarse recycled concrete aggregate (RCA) in ZSC properties. Five mixes were manufactured, each with a different percentage of coarse RCA (0%, 25%, 50%, 75%, and 100%). Compressive strength, flexural strength, ultrasonic pulse velocity (UPV), dry bulk density, and water absorption of recycled aggregate ZSC were conducted at 7, 28 and 90 days. Experiments revealed that the inclusion of coarse RCA in ZSC degraded the quality of manufactured concrete. At 90 days, in comparison to the control mix, the minor drop was at 25% coarse RCA incorporation, which resulted in a 6.2%, 4.1%, 2%, and 2.4% drop in compressive strength, flexural strength, UPV, and dry bulk density, respectively, while there was a 24.4% increase in water absorption. The highest drop of recycled aggregate ZSC at 100% incorporation resulted in a 41.7%, 19.1%, 8.6%, and 7.6% drop in compressive strength, flexural strength, UPV, and dry bulk density, respectively, while there was a 158.8% increase in water absorption. [ABSTRACT FROM AUTHOR]

In this research, a new type of natural fiber-rubber-cement (FRC) composite for roofing applications is presented. This composite was made with Portland cement, coated oil palm fibers, and modified waste tire rubber powders. The implementation of fiber coating and rubber modification methods has resulted in a more effective blending and binding of the fibers and rubber powders with the cement paste. This has notably improved the adhesion between the fibers and cement, as well as between the rubber powders and cement within the composite. The FRC composite demonstrated significantly lower water absorption and thermal conductivity, with reductions of 85% and 18%, respectively, compared to the fiber-cement (FC) composite lacking rubber powders. Additionally, the FRC composite exhibited improvements in flexural strength and noise reduction coefficient by 10% and 20%, respectively, in comparison to the FC composite. Thus, incorporating rubber powders can enhance the properties of the FC composite. Consequently, the FRC composite is proposed as a viable alternative roofing material suitable for use in energy-efficient buildings.

Recycling crushed clay bricks (CCB) in concrete is a sustainable and cost-effective process. Huge quantities of crushed clay bricks waste cause many serious environmental problems around the world. To deal with this problem, crushed bricks were recycled in the concrete industry as an alternative to natural resources, and the brick powder was reused as a partial replacement for cement. The objective of this paper is to study the effect of crushed clay bricks on the characteristics of concrete. 7 concrete mixtures containing coarse crushed brick aggregate (CCBA) and fine crushed brick aggregate (FCBA) were prepared as a complete substitute for sand and dolomite, respectively. Clay brick powder (CBP) and silica fume were used as a partial substitute for cement by 5%, 10%, and 15% of its weight. The water-to-cement ratio was 0.35. For comparison, a control mixture was prepared. Various tests were conducted to evaluate the performance of concrete. The results showed that the workability of the different mixtures containing CCB decreased compared to that of the reference mixture. The compressive strength values of mixtures containing CCBA had a clear decrease compared to the reference mix at 7, 28, and 56 days of curing. The modulus of rupture results had the same path as compressive strength results. The thermal conductivity coefficient for mixtures including CCBA decreased compared to the control mix. Scanning Electron Microscope images indicated crystals of calcium silicate hydrate because of the pozzolanic interaction between the brick powder and the fine crushed clay bricks with calcium hydroxide. [ABSTRACT FROM AUTHOR]

New composites produced with recycled waste are needed to manufacture more sustainable construction materials. This paper aimed to analyze the hygrothermal and mechanical performance of plasterboard with a polymethylhydrosiloxane (PMHS) content, incorporating recycled PET microplastic waste and varying factors such as PMHS dose, homogenization time, and drying temperature after setting. A cube-centered experimental design matrix was performed. The crystal morphology, porosity, fluidity, water absorption, flexural strength, and thermal conductivity of plasterboards were measured. The results showed that incorporating recycled PET microplastics does not produce a significant difference in the absorption and flexural strength of plasterboards. However, the addition of recycled PET reduced the thermal conductivity of plasterboards by around 10%. [ABSTRACT FROM AUTHOR]

Concrete structures that are submerged in water suffer from attacks by harmful salts and acids such as sulfates and chlorides. Therefore, using waste like polypropylene (PP) fiber to prevent environmental accumulation and glass sand (GS) (rich in silica) may help solve this problem. This study aims at the possibility of replacing 25, 50, and 75% of the fine aggregate with GS and using PP fibers at a rate of 1% of the total volume to produce sustainable mortar. The mechanical and physical properties, including compressive strength, flexural strength, splitting tensile strength, and density, were investigated. The water absorption was also monitored using indirect tests for an indication of the permeability of the mortar. The tests were evaluated on different curing ages (7, 14, 28, and 90 days) by two types of curing mediums: tap water and groundwater. The results indicated that at age 28 days, the specimens cured by groundwater and containing 25% and 50% of GS and 1% PP fiber improved the compressive strength by 7.5% and 7.4%, respectively, while the splitting tensile strength improved by 6.17% and 6.38%, and the flexural strength improved by 11.42% and 10.71%, respectively. In contrast, the specimens containing 75% GS and 1% fiber exhibited a clear reduction in compressive, splitting, and flexural strengths, reaching 7.7%, 6.36%, and 11.44%, respectively. However, the mean reduction of density and water absorption was 4.17% and 0.22%, respectively. The findings of this research introduced a comprehensive understanding of the groundwater-resistant mortar using GS and PP fibers. [ABSTRACT FROM AUTHOR]

Wood waste, which constitutes an important component of solid waste, is produced by the wood industry, and especially in the processing one. The wood industry includes tree bark, sawdust, planer shavings, sander dust etc. produces unwanted products and/or wastes. This study investigated the usability of sawdust of fruit trees in the production of Medium Density Fiberboard (MDF) and some technological properties of the produced MDF panels. Sawdust of fruit trees was mixed to beech fibers at the ratio of 10, 20 and 30% by weight. The mats were manually formed using 13% urea formaldehyde and pressed at a temperature of 185°C for 8 min in a computer control press. The MDF panel samples of water absorption (WA), thickness swelling (TS), surface hardness, surface roughness, MOR and MOE were investigated. It was determined that the values of WA and TS decreased with increasing the ratio of sawdust. Modulus of rupture (MOR), modulus of elasticity (MOE), surface hardness, surface roughness parameters (Ra, Rq and Rz) values of panel samples increased with increasing the ratio of sawdust from panels. Based on these results, it is advisable that wood sawdust fruit-trees can be used as an alternative raw material source in MDF production. [ABSTRACT FROM AUTHOR]

The release of steel slag into the environment has substantial repercussions, simultaneously affecting both the ecosystem and the economy. Therefore, the management and recovery of this waste demand careful consideration. In the context of the circular economy, this study aims to explore the feasibility of utilizing steel slag waste as a substitute aggregate for natural coarse and fine aggregates in the production of high-quality concrete. Throughout this research, concrete mixtures were developed by varying natural aggregate substitution rates with steel slag waste at 0, 25, 50, 75, and 100%. Comprehensive tests, encompassing physical, mineralogical, chemical, and mechanical analyses, were conducted on the steel slag waste to ascertain its primary technical properties. In all mixtures incorporating steel slag waste, compressive strength tests consistently revealed values surpassing those of the reference concrete. Notably, there were improvements of approximately 12% for coarse aggregate substitution and 32% for sand substitution. Assessments of flexural strength at 7 and 28 days underscored the substantial positive influence of fine and coarse aggregate substitution, especially at a 50% fine aggregate replacement, contributing significantly to enhanced flexural strength compared to conventional concrete. Furthermore, laboratory examinations indicated that the 28-day compressive and flexural strength, as well as water absorption of concrete, increased with slag content, albeit at the expense of reduced workability. Ultimately, the findings demonstrate the effective utilization of slag as a replacement for natural aggregates, maintaining the compressive and flexural strength of the concrete. [ABSTRACT FROM AUTHOR]

This study focused on the experimental investigation of the effect of palm kernel shell particulate reinforcement on the mechanical properties of cement-based tiles. Five samples of cement tiles reinforced with different compositions of kernel shell of 1440 µm particle size at predetermined moisture content were produced against a control sample to ascertain the composition that offered the best suitable properties for the functional requirements of cement tiles at reduced cost. For all the samples produced, evaluations for bulk density, apparent porosity, water absorption capacity, and flexural strength were investigated. The results showed that porosity, water absorption capacity, and apparent density decreased with an increase in the palm kernel shell compositions while bulked density increased. The variation with 80 % cement and 20 % palm kernel shell fibre reinforcement (Sample B) demonstrated optimal tile quality with apparent porosity of 10.35 %, a water absorption capacity of 5.47 %, bulk density of 1.89 g/cm³, and flexural strength of 37.21 kgF/cm² . It was evident that the flexural strength of sample B met the ASTMC293 standard cement tiles requirement of 35 kgF/cm² to 40 kgF/cm2 thus the optimal volume fraction with improved surface characteristics and recommended for applications where hard and heavy materials are used on tiles. [ABSTRACT FROM AUTHOR]

Bisphenol-C epoxy cinnamate (ECC) resin was synthesized by reacting 8.09 g epoxy resin of bisphenol-C, and 3.70 g cinnamic acid using 25 ml 1,4-dioxane as a solvent, and 1 ml triethylamine as a catalyst at reflux temperature for 1–6 h. Solid epoxy cinnamate is found to have excellent solubility in common organic solvents, 10.4–4.1 mg KOHg−1 acid values, and 303.0–426.0 mg KOH g−1 hydroxyl values. FTIR and 1HNMR spectral data supported the structure of ECC. Thermal polymerization of ECC followed by decomposition is supported by DSC exothermic (142.9°°C) and broad endothermic (300°°C) transitions. ECC followed three steps of degradation kinetics. The first step followed first-order (1.13) degradation kinetics, while the second (2.40) and the third (0.58) steps followed fractional-order degradation kinetics. The energy of activation for the second and third steps is more than 3 times that of the first step. The entropy change (ΔS*) for the first (− 176.3JK−1 mol−1) and third (− 84 JK−1 mol−1) steps are found large and negative, while it is positive for the second step (9.4 JK−1 mol−1). Jute-, Glass- and Jute-biomass-ECCS composites showed moderate to fairly good tensile strength, flexural strength, electric strength, and fairly good volume resistivity. J-ECCS and G-ECCS composites showed high water absorption tendency and excellent hydrolytic stability against water, 10% aq. HCl and 10% aq. NaCl and even in boiling water. The composites may be useful during natural calamities and under diverse environmental conditions. [ABSTRACT FROM AUTHOR]

Natural fibre (flax) plain type of woven fabric is developed by using solid braided yarn and is utilised as filler material and PLA (polylactic acid) as a matrix. Solution casting is then used to create sheets of pure PLA and flax fabric–PLA. Composites are manufactured by sheets sequencing technique using the hot compression moulding method. Water absorption, thickness swelling and flexural tests are performed in loading directions of warp and weft of the composites. Results revealed that the absorption of water and swelling of thickness are enriched with an addition of flax fabric. The weft direction loaded composite displayed greater values of water uptake and thickness swelling. The warp direction loaded composites demonstrated the highest flexural strength (92.3 MPa) and modulus (4.5 GPa) compared to weft direction loaded composites. These values are decreased after water absorption. [ABSTRACT FROM AUTHOR]

This paper focuses on the preparation and characterization of the reinforcement of an epoxy with metakaolin clay of grain size (45 ≤ d ≤60) µm as an eco-friendly inorganic material to improve its mechanical and physical properties with low-cost filler. Various proportions of (0, 15, 30, 45, and 60) wt.% of metakaolin were intrinsically mixed with epoxy to investigate their physical properties represented by moisture absorption. Tensile test was employed to determine their mechanical properties such as ultimate tensile strength, yield strength, modulus of elasticity, as well as compressive strength, flexural strength and Vickers hardness test which was used to specify hardness number. The obtained experimental results showed improvement in the modulus of elasticity, compressive strength, and hardness with the addition of metakaolin. In contrast, the yield and tensile strength of the composite specimens which decrease with the increase in metakaolin content. Also, absorption of moisture test at different immersion times was carried out with different filler loadings of the prepared composite. The results of the test showed that a decreasing in water uptake for specimens with higher metakaolin content. From optical surface investigation using an optical microscope, it was found a reduction in porosity with an increase in the concentration of metakaolin and the specimen with weight percent of 60% is the highest homogeneity and less porosity and voids as compared to the other specimens. The prepared composite may find potential practical applications such as anti-corrosion coating, automotive components and medical devices. [ABSTRACT FROM AUTHOR]

The paper assesses and compares the strength of cement mortar that is partially replaced with rice husk ash (RHA). The primary objective of this study is to evaluate the feasibility of using RHA in construction projects as a cost-effective and sustainable alternative to traditional cement-based mortar. The study also seeks to address the pressing environmental issues associated with the disposal of agricultural waste. The study results expect to provide valuable insights into the potential benefits and drawbacks of using RHA in construction projects, particularly in terms of its impact on the durability, strength, and overall quality of the mortar. The idea is to generate wealth by selling RHA to potential buyers instead of disposing of it. Samples of RHA are being mixed into the cement mortar at replacement levels ranging from 5% to 25%. A range of laboratory tests is being conducted to evaluate properties such as particle size distribution, compressive strength, flexural strength, bulk density, and water absorption. The results from the laboratory tests show that as the percentage of RHA increases, the density of the RHA with cement mortar decreases from 2.316 kg/m3 to 1.853 kg/m3. Water absorption of RHA with cement mortar increases from 0.45% to 8.1% as the percentage of RHA increases from 0% to 25%. Compressive strength decreases from 23.4 KN/m2 to 7.31 KN/m2, and flexural strength decreases from 3.93 KN/m2 to 0.54 KN/m2. An optimal percentage of RHA with cement mortar is recommended to be between 10% and 15%. [ABSTRACT FROM AUTHOR]

Chemical admixtures are widely used for the production of highperformance concrete, but they are responsible for environmental pollution and health issue during construction because of their chemical nature. Also manufactured admixtures are expensive, on this base recently, researches and attempts are focused to find alternatives, and using different natural or bio admixtures for concrete is a good choice. In this study, the impact of Grape Extract (GE), a natural additive, on the properties of concrete was investigated. Various GE percentages were used to investigate the properties of fresh and hardened concrete. The results show that there is a continuous workability enhancement and continuous splitting tensile strength loss with GE increase. Improvement of 28 days compressive strength by 18.5% was observed on using 0.22% GE, while no compressive and flexural strengths loss was observed with GE addition up to 0.55%. Finally, the results of the study showed that GE dosages can strongly impact the fresh properties and mechanical strength of concrete mixtures. So there is a chance to produce self-compacting concrete using GE natural admixture instead of chemical admixture but there is a need for further experimental tests. [ABSTRACT FROM AUTHOR]

The global challenge faced due to the impact of the construction industry on climate change, along with the issues surrounding sustainable waste disposal, has necessitated various research on using waste products as eco-friendly alternatives in construction. In this study, the avoidance of waste disposal through landfills in Australia was encouraged by incorporating lime kiln dust (LKD) and tire rubber waste (TRW) into masonry mixes to manufacture green bricks. Furthermore, the investigations in this article highlight the use of mercury intrusion porosimetry (MIP) to determine the durability of the LKD-TRW bricks when exposed to freeze–thaw (F-T) cycles by examining the pore size distribution within the bricks. The LKD waste was blended with ground granulated blast furnace slag (GGBFS) at a 70:30 blending ratio and combined with the TRW in stepped increments of 5% from 0 to 20% to produce these eco-friendly bricks. The compressive strength (CS), flexural strength (FS), frost resistance (FR), pore size distribution according to mercury intrusion porosimetry (MIP), and the water absorption (WA) properties of the bricks were assessed. The CS and FS values at 28 days of curing were recorded as 6.17, 5.25, and 3.09 MPa and 2.52, 2, and 1.55 MPa for 0, 5, and 10% TRW contents, respectively. Durability assessments using the F-T test showed that the bricks produced with 0% TRW passed as frost-resistant bricks. Furthermore, the results from the MIP test showed a total pore volume of 0.033 mL/g at 3 µm pore size for the 0% TRW content, further confirming its durability. Hence, the 0% LKD-TRW bricks can be utilized in cold regions where temperatures can be as low as −43 °C without deteriorating. Lastly, WA values of 7.25, 11.76, and 14.96% were recorded for the bricks with 0, 5, and 10% TRW, respectively, after the 28-day curing period. From all of the results obtained from the laboratory investigations, the LKD-TRW bricks produced with up to 10% TRW were within the satisfactory engineering requirements for masonry units.

This experimental study presents the influence of basalt fiber on the rheological and mechanical properties and the durability behavior of self-compacting concrete (SCC). In this study, a total of five self-compacting concrete mixtures were prepared: one as a control mix and the other mixes with 0.05%, 0.1%, 0.15%, and 0.2% basalt fibers. Slump flow and V-funnel flow tests were employed to assess the influence of basalt fibers on the rheological properties of fresh self-compacting concrete (SCC). Additionally, mechanical properties, including compressive strength, splitting tensile strength, and flexural strength, were analyzed. Furthermore, the mechanical properties were assessed following exposure to elevated temperatures (400 °C and 600 °C) as well as 100 and 200 freeze-thaw (F/T) cycles. Additionally, water absorption and ultrasonic pulse velocity tests were conducted on the SCC mixes after 28 days of curing. The results revealed that the addition of fiber has a significant effect on the rheological properties of fresh SCC mixtures. As the volume of fibers increases, the reduction in rheological properties increases. Basalt fiber had no effect on the compressive strength, while the splitting and flexural strength were significantly enhanced by 33% using basalt fiber. As temperatures and freezing-thawing cycles escalated, the mechanical properties of SCC exhibited a decline. Experimental findings indicated that elevating the temperature to 600 °C resulted in a decrease of over 20% in both the tensile and compressive strengths of SCC. Moreover, the results demonstrated that the incorporation of basalt fibers substantially enhanced the mechanical properties of SCC when subjected to high temperatures and freezing-thawing cycles. In addition, water absorption increased slightly by the incorporation of basalt fiber.

In a context where there is an increasing need for thermal treatments of wooden products, the current research contributes a description of the torrefaction treatment of two of the composite wood materials available on the international market. The present paper presents the importance of the torrefaction process for poplar plywood and medium-density fiberboard. In this paper, the positive aspects of the torrefaction process (decrease in water absorption, thickness swelling and shrinkage, and color) but also the negative aspects of mechanical resistance to static bending are presented. Poplar plywood (PW) and medium-density fiberboard (MDF) panels, with the initial dimensions of 2000 × 1250 mm, were used. From these, 300 × 300 mm samples were cut and torrefied using two different temperatures (170 and 190 °C) and two different periods (for 1 and 2 h). After the treatment, the samples were cut in different sizes (as necessary for each type of evaluation method) from different zones of the panels and used to evaluate the water absorption and thickness swelling, to determine their modulus of rupture, roughness, and color changes. The obtained results emphasize that the mass loses increase at high temperature as the main disadvantageous characteristics of torrefaction. Also, while the calorific power increases with the increase in the parameters of the torrefaction regime, the hygroscopicity and some mechanical properties of the material simultaneously decrease. [ABSTRACT FROM AUTHOR]

Physical and mechanical properties were evaluated for all-sided charred Pinus taeda and Eucalyptus bosistoana wood by hot plate contact heating system followed by treatment with linseed oil. The water absorption, volumetric swelling, wettability, hardness, modulus of rupture, and modulus of elasticity in bending strength and compression strength parallel to grain were determined. The water absorption and volumetric swell were determined after immersion in water, as measured at various intervals of water immersion up to 120 h. The results suggested that the contact charring process with the addition of a linseed oil application improved water absorption and volumetric swell properties of charred specimens compared to un-charred controls. Hardness of the charred wood decreased by 38% and 43% in P. taeda and E. bosistoana specimens, respectively, compared with their respective controls. The highest reductions were seen in modulus of elasticity and compression strength values in charred P. taeda specimens, while modulus of rupture (MOR) values decreased more in charred E. bosistoana specimens than in charred P. taeda specimens. These results suggested that charring of P. taeda and E. bosistoana wood does improve the moisture-related characteristics; however, their mechanical behavior and hardness decreased. [ABSTRACT FROM AUTHOR]

Hemp is one of the strongest and most durable commercially available natural fibre. Its biodegradability, low density, high fibre length, availability, low weight-to-strength ratio and more yield per acre makes it an ideal fibre for marine applications. Water absorption behaviour of any material is very important which mainly limits their use specifically in marine applications. The present work aims to study the absorption of ocean water, its kinetics and effects on the flexural properties of hemp reinforced composites. Absorption effects for epoxy and unsaturated polyester (UPE) reinforced with short hemp fibre, unidirectional and bidirectional hemp fabric were investigated by immersing samples in ocean and distilled water. The absorption of all composites followed Fickian diffusion with slight deviation due to swelling of fibres and formation of microcracks. It is observed that the water uptake of samples increased with increasing weight fraction. The flexural strength and modulus of composites degraded by approximately 10% and 20% for epoxy and UPE composites respectively, due to water absorption. The results indicated that hemp fibre based composites could be used for many lightweight components in marine applications. [ABSTRACT FROM AUTHOR]

Abstract Introduction: In this research, the effect of different sources of magnesium oxide and the effect of CaO/MgO ratio, as the main oxides that activate the reactions during wall tile firing, on the path of transformations and the formation of useful phases such as Anorthite, Diopside, and Wollastonite, and the reduction of the destructive phase of Gehlenite and free quartz was studied. Methods: Three groups with 12% wt. of calcium carbonate - as the main source of CaO supply - and different weight percentages (5, 7 and 10%) from local soils supplying MgO in Iran (Zanjan talc, Boroujard talc and Abdol-Abad dolomite) were built. After forming with a press, the mixtures were sintered in a fully industrial process and in a fast firing furnace. By means of X-ray diffraction test and with the help of Rietveld refinement method which was carried out in Maud software, the weight percentage of the forming phases of the final microstructure was quantitatively calculated. Findings: In the samples containing talc, with the increase of the weight percentage of talc and the decrease of CaO/MgO ratio, the weight percentage of Anorthite and Gehlenite phase increased and the Diopside phase decreased. Also, the coefficient of thermal expansion and moisture expansion test decreased by decreasing the ratio of CaO/MgO. In samples containing dolomite, increasing the weight percentage of CaO oxide, despite the acceptable weight percentage of MgO oxide, led the tendency of the structure towards the formation of more calcium aluminosilicates such as Anorthite and Gehlenite. The extreme increase of Gehlenite phase (6% wt.) caused a large increase in thermal expansion coefficient (8.35 x 10-6 units/degree Celsius) and moisture expansion percentage (0.12%) in the sample with 10%wt. dolomite.

AbstractIntroduction:In this research, the effect of CaO/MgO ratio, as the main oxides that activate the reactions during wall tile firing, was studied on the path of transformations and the formation of useful phases such as Anorthite, Diopside, and Wollastonite, and the reduction of the destructive phase of Gehlenite and free quartz.Methods: In the first part of the research, in order to determine the optimal amount of calcium carbonate as the main source of CaO supply, samples with 0, 6, 12 and 15% by weight were made. According to the obtained results, the sample with 12% by weight of calcium carbonate due to having less free quartz, more growth of Anorthite and less Gehlenite phase; Also, suitable water absorption of wall tiles, low coefficient of thermal expansion, lower moisture expansion percentage and suitable firing shrinkage percentage were selected as the best samples. In the second part of the research, mixtures with 12% by weight of calcium carbonate and 5%, 7% and 10% by weight of local soils supplying MgO in Iran (Broujerd talc) were made.Findings: After forming with a press, the mixtures were sintered in a fully industrial process and in a rapid baking furnace. By means of X-ray diffraction test and with the help of Rietveld refinement method which was carried out in Maud software, the weight percentage of the forming phases of the final microstructure was quantitatively calculated. By increasing the weight percentage of talc and decreasing the ratio of CaO/MgO to less than 4, the weight percentage of Diopside phase increased up to 15% by weight. Decreasing the ratio of CaO/MgO to less than 3 caused the growth of Diopside phase to decrease

In this study we evaluated the potential use of hazelnut shell powder in the production of a composite material. Polystyrene was used as a polymer matrix. This work presents the results of modifying hazelnut powder particles to create a polystyrene shell on their surfaces. Modification of the filler increased its contact angle wetted with water from θ = 60.16 ± 1.03 ° to θ = 87.02 ± 1.10 ° . Composite materials containing from 10 to 50 wt.% of modified hazelnut shell powder were prepared and studied. As a result of the experiments, it was found that the composites have optimal physical, mechanical, and operational properties at the following ratio: polystyrene 60–80 wt.%, modified hazelnut shell powder 20–40 wt.%. If the introduction of polystyrene was more than 90 wt.%, the flexural strength and Vickers hardness were quite low at the load of 200 g, and accordingly, the durability of such materials was not satisfactory. These samples are characterized by small percentages of hazelnut shells; therefore, the resulting material will be of pale, unsaturated color. The upper limit of the working temperature range for the composite lies between 265.0–376.0 °C, depending on the percentage of the hazelnut shell powder filling. [ABSTRACT FROM AUTHOR]

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