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Short glass fibers are generally used in posterior dental restorations to enhance the mechanical properties and improve the material microstructure. Two resin-based composites (S0 and SF) were formulated and characterized to investigate the influence of zirconium in their characteristics and properties. The organic part of the investigated materials was the same (BisGMA, TEGDMA, and a photochemical polymerization system), and in the inorganic part, besides quart, glassA, and hydroxylapatite with Zn, sample S0 contained strontium glass with zirconium and sample SF contained fiber powder of chopped zirconium. The samples were characterized by the degree of conversion (DC), mechanical properties, water sorption (WS), scanning electron microscopy (SEM), atomic force microscopy (AFM) before and after the WS test, and antimicrobial properties. The results obtained were subjected to one-way ANOVA and Tukey's statistical tests. Both samples had a high DC. Regarding the mechanical properties, both samples were very similar, except DTS, which was higher for the composite without fibers. After 14 days, the WS value of the SF sample was lower than that of the S0 sample. Water caused significant changes in the topography of the SF sample, but thanks to its antimicrobial properties and the diffusion phenomenon, SF had a more pronounced antimicrobial effect. This study shows that the addition of appropriate amounts of Sr-Zr-glass powder gives the material in which it is added similar properties to material containing chopped zirconium glass fiber powder. According to the antimicrobial test results, resin composites containing experimental zirconia fillings can be considered in future in vitro clinical studies for posterior reconstructions with significantly improved mechanical properties. [ABSTRACT FROM AUTHOR]

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo 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.)

The aim of this article was to assess the behavior of polymer composites under low-velocity impact considering stress concentrators (two side holes at the point of impact) and determine the residual mechanical properties of these materials using FAI (Flexural After Impact). Analysis of residual properties ascertained the effects of damage and stress concentrators, assessing their individual influence in increasing the stress concentration factor (K). This analysis was conducted via tests that consider the separate effects of each case and a formulation that relates them. In addition, this paper also assessed the influence of void percentage on the impact and residual strength, developing two E-glass fiber fabric-based composites with different void percentage. The tests performed showed that impact damage increased the concentration factor of the material by 18%, but in samples tested with side holes, damage decreased residual strength by only 5%. [ABSTRACT FROM AUTHOR]

Under high temperatures, fiber-reinforced polymers are destroyed, releasing heat, smoke, and harmful volatile substances. Therefore, composite structural elements must have sufficient fire resistance to meet the requirements established by building codes and regulations. Fire resistance of composite materials can be improved by using mineral fillers as flame-retardant additives in resin compositions. This article analyzes the effect of fire-retardant additives on mechanical properties and fire behavior of pultruded composite profiles. Five resin mixtures based on vinyl ester epoxy and on brominated vinyl ester epoxy modified with alumina trihydrate and triphenyl phosphate were prepared for pultrusion of strip profiles of 150 mm × 3.5 mm. A series of tests have been conducted to determine mechanical properties (tensile, flexural, compression, and interlaminar shear) and fire behavior (ignitability, flammability, combustibility, toxicity, smoke generation, and flame spread) of composites. It was found that additives impair mechanical properties of materials, as they the take place of reinforcing fibers and reduce the volume fraction of reinforcing fibers. Profiles based on non-brominated vinyl ester epoxy have higher tensile, compressive, and flexural properties than those based on brominated vinyl ester epoxy by 7%, 30%, and 36%, respectively. Profiles based on non-brominated epoxy resin emit less smoke compared to those based on brominated epoxy resin. Brominated epoxy-based profiles have a flue gas temperature which is seven times lower compared to those based on the non-brominated epoxy. Mineral fillers retard the spread of flame over the composite material surface by as much as 4 times and reduce smoke generation by 30%. [ABSTRACT FROM AUTHOR]

Discontinuous fibre reinforced polymers are widely used in various industry sectors and often replace conventional materials, due to lower production costs and their lightweight structure. For improvement of the component design, detailed knowledge of the failure mechanisms are necessary. To better understand the defect formation and thus the micro-mechanics, the strain behaviour in single fibres was analysed by micro-mechanical simulations of Representative Volume Elements (RVE). Therefore, selected fibres - similar orientated as in the real structure - were chosen for detailed analysis. Additionally, the defect formation next to selected fibres was investigated by X-ray computed tomography (CT). Furthermore, the critical fibre length was estimated based on the protruding fibre length of the fracture surface. Overall the simulation results correspond to theory. However, the detailed local inspection of the experimental volume data showed a rather strong influence of neighbouring fibres. [ABSTRACT FROM AUTHOR]

The complete flax stem, which contains shives and technical fibres, has the potential to reduce the cost, energy consumption and environmental impacts of the composite production process if used directly as reinforcement in a polymer matrix. Earlier studies have utilised flax stem as reinforcement in non-bio-based and non-biodegradable matrices not completely exploiting the bio-sourced and biodegradable nature of flax. We investigated the potential of using flax stem as reinforcement in a polylactic acid (PLA) matrix to produce a lightweight, fully bio-based composite with improved mechanical properties. Furthermore, we developed a mathematical approach to predict the material stiffness of the full composite part produced by the injection moulding process, considering a three-phase micromechanical model, where the effects of local orientations are accounted. Injection moulded plates with a flax content of up to 20 V% were fabricated to study the effect of flax shives and full straw flax on the mechanical properties of the material. A 62% increase in longitudinal stiffness was obtained, resulting in a 10% higher specific stiffness, compared to a short glass fibre-reinforced reference composite. Moreover, the anisotropy ratio of the flax-reinforced composite was 21% lower, compared to the short glass fibre material. This lower anisotropy ratio is attributed to the presence of the flax shives. Considering the fibre orientation in the injection moulded plates predicted with Moldflow simulations, a high agreement between experimental and predicted stiffness data was obtained. The use of flax stems as polymer reinforcement provides an alternative to the use of short technical fibres that require intensive extraction and purification steps and are known to be cumbersome to feed to the compounder. [ABSTRACT FROM AUTHOR]

Long-fiber thermoplastic (LFT) materials compounded via the direct LFT (LFT-D) process are very versatile composites in which polymers and continuous reinforcement fiber can be combined in almost any way. Polycarbonate (PC) as an amorphous thermoplastic matrix system reinforced with glass fibers (GFs) is a promising addition regarding the current development needs, for example battery enclosures for electromobility. Two approaches to the processing and compression molding of PC GF LFT-D materials with various parameter combinations of screw speed and fiber rovings are presented. The resulting fiber lengths averaged around 0.5 mm for all settings. The tensile, bending, Charpy, and impact properties were characterized and discussed in detail. Special attention to the characteristic charge and flow area formed by compression molding of LFT-D materials, as well as sample orientation was given. The tensile modulus was 10 GPa, while the strength surpassed 125 MPa. The flexural modulus can reach up to 11 GPa, and the flexural strength reached up to 216 MPa. PC GF LFT-D is a viable addition to the LFT-D process, exhibiting good mechanical properties and stable processability. [ABSTRACT FROM AUTHOR]

In this paper, nanoparticles obtained by Sol-gel method have been incorporated as a filler in glass fiber/polyester composite in order to improve the mechanical properties of the resulting material. This work covered on the characterization and the study of the polymer matrix with 5 wt.%nano TiO 2 , 5 wt.%nano Al 2 O 3 , 5 wt.%nano SiO 2.The results obtained revealed that sol-gel powders with a spherical morphology have excellent thermal stability. Acoustic emission analysis was used to investigate the microscopic damage mechanisms and progression in glass fiber reinforced nanocomposites. Thus, acoustic emission from four modes of approval has been identified: matrix cracking, matrix/fiber decohesion, delamination and fiber breakage. This study shows the increase of mechanical performance and the decrease of damage modes of @Polyester. From the SEM images, the good dispersion of nanofillers, absence of agglomerates, the good affinity with the improving of the interface compatibility were presented. [ABSTRACT FROM AUTHOR]

Copyright of Al-Nahrain Journal for Engineering Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) 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.)

Epoxy composites with glass fiber reinforcement can be found in the automotive and aerospace industries. In this study, the properties of the epoxy matrix were enhanced by processing composites filled with ceramic particles of silicon carbide (SiC). At first, SiC-filled E-glass fiber-reinforced epoxy composites/sandwich structures were processed using the hand layup technique. Next, processed composites were characterized using a tensile tester and an Izod impact tester to determine the best mixing ratio of ceramic-embedded epoxy composites. The highest mechanical properties were obtained according to ASTM D638 and D256 standards. Next, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), analysis of differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) were carried out respectively to find out the presence of functional groups, surface morphology, crystallographic structure, glass transition temperature (Tg) and thermal/material stability of processed composites. In the end, the study elaborates that the mechanical properties of epoxy matrix composites were improved by the addition of SiC ceramic fillers, and among processed composites, 10% SiCE composite carried the highest properties, including the Tg value of 62.8 °C, 69.87 MPa for tensile strength and 57.12 kJ m−1 for impact strength. [ABSTRACT FROM AUTHOR]

Fiber-reinforced polymer (FRP) composite materials are very versatile in use because of their high specific stiffness and high specific strength characteristics. The main limitation of this material is its brittle nature (mainly due to the low stiffness and low fracture toughness of resin) that leads to reduced properties that are matrix dominated, including impact strength, compressive strength, in-plane shear, fracture toughness, and interlaminar strength. One method of overcoming these limitations is using nanoparticles as fillers in an FRP composite. Thereby, this present paper is focused on studying the effect of nanofillers added to glass/epoxy composite materials on mechanical behavior. Multiwall carbon nanotubes (MWCNTs), nano-silica (NS), and nano-iron oxide (NFe) are the nanofillers selected, as they can react with the resin system in the present-case epoxy to contribute a significant improvement to the polymer cross-linking web. Glass/epoxy composites are made with four layers of unidirectional E-glass fiber modified by nanoparticles with four different weight percentages (0.1%, 0.2%, 0.5%, and 1.0%). For reference, a sample without nanoparticles was made. The mechanical characterizations of these samples were completed under tensile, compressive, flexural, and impact loading. To understand the failure mechanism, an SEM analysis was also completed on the fractured surface. [ABSTRACT FROM AUTHOR]

Thermoplastics and fiber-reinforced thermoplastics represent great deals in nowadays industries and applications where some of these applications are projected to wet environment. The present study investigates the effect of water moisture on the bearing strength (BS) of Polypropylene (PP) and glass fiber (GF) reinforced Polypropylene (GFRPP) composites. PP and GFRPP are produced by injection molding using different GF weight fractions (wt%), 10, 20, and 30 wt%, and two different initial fiber lengths 12 and 24 mm. A burnout test indicated that produced specimens with 12 mm long fibers have higher final fiber lengths than those made of 24 mm long fibers. More water was absorbed for higher GF weight fractions. The results of the dry bearing test showed higher bearing strengths for specimens with higher GF wt% and longer fibers. The same observation was obtained from wet tests, while, wet-tested specimens of all compositions have higher strengths than their dry counterparts. Strain-at-break seemed to be significantly reduced by water absorption for all specimens. Specimens tested in wet conditions have different fracture morphology than dry ones due to the change in the mechanical behavior of the materials after water immersion. [ABSTRACT FROM AUTHOR]

Accordingly with the principles of the circular economy, mixed plastic wastes can be recycled also by thermoforming, getting new non-oriented fibers composite materials. This study highlights the mechanical behavior of new composite material plates containing recycled glass fibers as reinforcing element and ABS-PMMA mixture as matrix, as well as an efficient way to convert a manufacturing process wastes in a product. The mechanical behavior of new composite material plates was evidenced by tensile, flexural and compression tests. In addition a surface morphology analysis was performed. [ABSTRACT FROM AUTHOR]

Increasing demand for energy-efficient means of transport has steadily intensified the trend towards lightweight components. Thermoplastic glass fiber composites (organo sheets) play a major role in the production of functional automotive components. Organo sheets are cut, shaped and functionalized by injection molding to produce hybrid components, such as those used in car door modules. The cutting process produces a considerable amount of production waste, which has thus far been thermally recycled. This study develops a closed mechanical recycling process and analyzes the different steps of the process. The offcuts were shredded using two shredding methods and implemented directly in the injection-molding process. Using tensile tests and impact bending tests, the material properties of the recycled materials were compared with the virgin material. In addition, fiber length degradation via the injection-molding process and the influence of the waterjet-cutting process on the mechanical properties are investigated. Recycled offcuts are both comparable to new material in terms of mechanical properties and usability, and are also economically and ecologically advantageous. Recycling polypropylene waste with glass fiber reinforcement in a closed loop is an effective way to reduce industrial waste in a sustainable and economical production process. [ABSTRACT FROM AUTHOR]

Long Fiber Reinforced Thermoplastic (LFT) is a lightweight, high-strength, and easy-to-recycle new vehicle composite material, and has good mechanical properties, heat resistance, and weather resistance, which has found increasing application in automobile industry. It is of importance to understand the relationship between micro phase, macro-mechanical properties and the structural performance of automobile components. This article evaluates the performance of LFT from the level of material to automobile components. The mechanical properties of LFT were numerically and theoretically predicted to provide instruction for the next material choice. Two typical structural components, namely, car seat frame and bumper beam, were selected to evaluate the performance of LGF/PP compared with other competing materials in terms of mechanical properties and cost. In the case of the same volume, the seat frame of 40% LECT/PP composite material is lighter and cheaper, which is conducive to energy saving and emission reduction. It was shown that the 40% LECT/PA66 car bumper beam had a higher energy absorption ratio, lighter weight, higher specific energy absorption, and advantageous material cost. LFT is a promising candidate for existing automobile components with its performance fulfilling the requirements. [ABSTRACT FROM AUTHOR]

In this study, crushing and energy absorption behavior of carbon nanotube (CNT) reinforced glass fiber/epoxy (GFRP) and carbon fiber/epoxy (CFRP) composite tubular structures has been investigated. The study consists of two main parts. First part deals with the experimental studies. At this stage, functionalized multi-walled CNT added (at weight percentages of 0.1; 0.2; 0.3; 0.5; 1; 2%) and additive free GFRP composite plates were produced using hand lay-up method and tension, compression and shear tests were carried out to determine mechanical properties of the composite materials. As a result of these investigations, 0.5% CNT addition is determined to be most suitable rate for the composite in terms of tension, compression, and shear strength. The second part deals with the numerical studies. At this stage, quasistatic crushing and energy absorption characteristics of circular and square cross-section GFRP and CFRP tubes were investigated numerically using the determined mechanical properties in a commercial finite element based software (ABAQUS). The mechanical properties of CFRP tubes were taken from the existing literature. As a result of numerical studies, the specific energy absorption capacity of circular CFRP tubes was found to be most efficient compared to the other tubes. [ABSTRACT FROM AUTHOR]

After primary uses of the plastic product, most developing countries like Ethiopia are facing a shortage of postconsumer disposal waste sites and it became a very serious problem on environmental pollution due to its nonbiodegradable nature. For this reason, regenerating and using the waste product as resources and reducing environmental pollutions are a great opportunity. This research is aimed at the manufacturing of composite materials from waste poly(ethylene terephthalate) (PET) bottles reinforced with glass fibers and filled with waste glass powder for floor tile applications. The tile composites were prepared by the melt-mixing method followed by compression molding. The effect of filler, fiber, and PET matrix loading on the composite was investigated using their tensile, compression, and flexural strength tests. The sample was characterized using a universal testing machine. PerkinElmer FTIR instrument was also used. For this, eleven samples prepared by varying the glass fiber weight % from 0 to 10, PET matrix weight % from 70 to 85, and glass powder filler weight % from 5 to 20. The measurement results of the composite were maximum tensile strength (81.625 MPa) and flexural strength (1067.59 MPa) recorded at 10%weight of glass fiber, 85% weight of PET matrix, and 5%weight of window glass filler. The maximum compressive strength is 1876.14 MPa at 10% weight glass fiber, 70 wt% PET matrix, and 20 wt% window glass filler. Based on this, the tensile strength and flexural strength increased with increased weight % of glass fiber and decreased with increased window glass filler. The FTIR spectrum shows some of the groups that have been removed from the recycled PET; this explains the brittleness of the recycled PET as compared to the waste bottle PET. The microstructure was uniformly distributed, and the material became opaque, probably because the decrease in chain length improves chain packing, increasing the crystallinity degree and crystal size. [ABSTRACT FROM AUTHOR]

Sulfate-rich dispersive soils are worldwide responsible for damaging earthworks, such as roadway roadbeds and embankments. One of the causes for such behavior is the high amount of exchangeable sodium ions adsorbed on their clay particles vastly increasing erosion susceptibility, being responsible for problems as piping, ravines, and water turbidity. In order to reduce the erodibility, it is usual to treat such soils with calcium-based stabilizers. However, in the presence of sulfates, when combined with calcium-based stabilizers in the soil, reactions take place between stabilizers and sulfates to form expansive minerals. Namely, these minerals are known as ettringite and thaumasite and are responsible for excessive volumetric swell. In this context, the present research aims to develop alternative soil stabilizers (industrial byproducts plus artificial pozzolans) and reinforcements (fiberglass) to solve problems associated with sulfate-rich dispersive soils. Thus, a binder composed of carbide lime and ground glass was used. In addition, fiberglass was applied to look for enhanced mechanical properties of the materials. To assess the efficiency of the proposed stabilization and reinforcement, unconfined compressive and splitting tensile strength, ultrasonic pulse velocity, wet and dry durability, and fatigue life tests were carried out. Soil–ground glass–carbide lime-fiberglass blends were molded at different porosities, carbide lime, ground glass, and fiberglass contents. Results show that unconfined compressive and split tensile strength and initial shear modulus are highly dependent on changes in porosity and lime content. Durability, expressed as the accumulated loss of mass, could be assessed through the adjusted porosity/lime index (η/Liv). Fiberglass inclusion resulted in higher tensile strength. The fatigue life was correlated to the η/Liv index through a negative exponent. The greater the carbide lime level, the smaller was the fatigue life for all treated specimens. An increase in porosity results in fewer contacts between particles, whereas an increase in carbide lime content enhanced the specimen's rigidity. [ABSTRACT FROM AUTHOR]

As a new and innovative processing method for fabrication for fiber-reinforced thermoplastic composites (CFRTs), the feasibility of ultrasonic welding technology was proven in several studies. This method offers potential for the direct manufacturing of CFRT-metal structures via embedded pin structures. Despite the previous studies, a deeper understanding of the process of energy input and whether fibers work as energy directors and consequently can, in combination with chosen processing parameters, influence the consolidation quality of the CFRTs, is still unknown. Consequently, the aim of this work is to establish a deeper process understanding of the ultrasonic direct impregnation of fiber-reinforced thermoplastics with an emphasis on the fiber's function as energy directors. Based on the generated insights, a better assessment of the feasibility of direct, hybrid part manufacturing is possible. The produced samples were primarily evaluated by optical and mechanical test methods. It is demonstrated that with higher welding time and amplitude, a better consolidation quality can be achieved and that independent of the process parameters chosen in this study, no significant fiber breakage occurs. This is interpreted as a sign of a gentle impregnation process. Furthermore, based on the examination of single roving and 5-layer set-ups, it is shown that the glass fibers function as energy directors and can influence the transformation of sonic energy into thermal energy. In comparison to industrially available CFRT material, the mechanical properties are weaker, but materials and processes offer potential for significant improvement. Based on these findings, proposals for a direct impregnation and joining process are made. [ABSTRACT FROM AUTHOR]

Copyright of Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji is the property of Gazi University 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 this study, the effect of functionalized nanoclay (with silane and amine groups) on the mechanical properties and impact behavior of glass fiber / Kevlar-epoxy hybrid composites was experimentally investigated. Nanoclay functionalized at three different concentrations (0%, 1%, and 3%) was mixed into the epoxy resin. Composite samples with layer 12 have been manufactured by handlayup method. The mechanical properties and impact behaviors under 30J were examined on the prepared composites. The comparisons between the nanoclay and non-nanoclay samples were carried out by using contact force, deflection, impact energy, velocity and time data of the impact tests. Mechanical strength and impact properties of 1% nanoclay added hybrid composites how better performance than that of 0% and 3% nanoclay added hybrid composites. As a result of the good dispersion of clay in the matrix-fiber interface in samples with 1% nanoclay addition, the impact values are reduced by 10% and load bearing capacity is increased to 22%. Futhermore, among bare and 3% nanoclay added hybrid composites, the highest hardness value of 23.60 HV obtained from 1% nanoclay added hybrid composite structures. [ABSTRACT FROM AUTHOR]

Shape memory polymers (SMPs) are a new class of materials in which their shapes can be changed over time. Despite their lightness and ease of fabrication, SMPs have very low recovery forces and are therefore inefficient when high loads are applied. To improve the mechanical properties of polymeric materials, glass fiber (GF) is commonly used as a reinforcement. The purpose of this study was to demonstrate a four-dimensional (4D) printing process using material extrusion additive manufacturing on both polylactic acid (PLA) and thermoplastic polyurethane (TPU). The goal was to improve the recovery forces in SMPs. GF roving was fed continuously into the nozzle of a three-dimensional (3D) printer to fabricate composite specimens. Also, multi-layer PLA/TPU specimens were printed. There was a measurement of shape fixity, shape recovery, and force recovery ratios. A multi-objective function analysis was performed to determine the optimum material based on recovery force priority in this study. In terms of recovery force, GF showed a superior effect. For composite specimens, shape fixity and recovery ratios decreased and increased, respectively. According to the result of optimization, PLA with 6.62 % GF proved to be the best material. PLA's recovery force has been improved by annealing heat treatment. Furthermore, cyclic experiments up to three cycles were conducted to evaluate the performance of the optimum material. [ABSTRACT FROM AUTHOR]

Many properties of materials exhibit a heavy dependency on the domain/grain size due to the change in interface density. Here, we show that in bulk Ni2Mn1+xGa1−x alloys (0.4 < x < 0.7), the exchange bias (EB) effect appears in the reentrant spin glass region and the magnitude of exchange bias (HEB) depends on the size of the ferromagnetic (FM) cluster in the antiferromagnetic (AFM) matrix. It was found that HEB first increases and then deceases as the size of the FM cluster decreases, which shows a non-monotonical relationship with the FM cluster size, and the relationship is similar to the grain size dependence of material properties such as the mechanical strength of metals and dielectric permittivity of ferroelectric ceramics. Further phase field simulation results repeat this phenomenon and illustrate that the change in EB can be attributed to the change in density of the FM/AFM interface, which provides a regulatable extra bias field through the Dzyaloshinskii–Moriya interaction. This work provides a method to tune HEB in bulk materials and reveals the mechanism of the dependency of EB on the FM cluster size, which could guide the design of bulk exchange-bias materials. [ABSTRACT FROM AUTHOR]

High-performance composites based on basalt fibers are becoming increasingly available. However, in comparison to traditional composites containing glass or carbon fibers, their mechanical properties are currently less well known. In particular, this is the case for laminates consisting of unidirectional plies of continuous basalt fibers in an epoxy polymer matrix. Here, we report a full quasi-static characterization of the properties of such a material. To this end, we investigate tension, compression, and shear specimens, cut from quality autoclave-cured basalt composites. Our findings indicate that, in terms of strength and stiffness, unidirectional basalt fiber composites are comparable to, or better than epoxy composites made from E-glass fibers. At the same time, basalt fiber composites combine low manufacturing costs with good recycling properties and are therefore well suited to a number of engineering applications. [ABSTRACT FROM AUTHOR]

In this research, three kinds of carbon fiber (CF) with lengths of 1, 3, and 25 mm were prepared for processing composite. The effect of submicron glass fiber addition (sGF) on mechanical properties of composites with different CF lengths was investigated and compared throughout static tests (i.e., bending, tensile, and impact), as well as the tension-tension fatigue test. The strengths of composites increased with the increase of CF length. However, there was a significant improvement when the fiber length changed from 1 to 3 mm. The mechanical performance of 3 and 25 mm was almost the same when having an equal volume fraction, except for the impact resistance. Comparing the static strengths when varying the sGF content, an improvement of bending strength was confirmed when sGF was added into 1mmcomposite due to toughened matrix. However, when longer fiber was used and fiber concentration was high, mechanical properties of composite were almost dependent on the CF. Therefore, the modification effect of matrix due to sGF addition disappeared. In contrast to the static strengths, the fatigue durability of composites increased proportionally to the content of glass fiber in the matrix, regardless to CF length. [ABSTRACT FROM AUTHOR]

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design 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.)

This paper presents an experimental study on the development of biocomposite material by using sawdust (SD) and rice husk (RH). The use of composite in the present production has increased dramatically since the 1970's. Traditional material like aluminum, steel, iron and copper etc. may be easily replaced by using this classical biocomposites. The tensile test, hardness and tear resistance test were conducted in a Universal testing machine as per ASTM D638, ASTM D2240 and ASTM D1004 standard, respectively. Although commercial industries have increasingly been concerned with the low cost, light weight and eco-friendly material, the biocomposite material has also a great potential for reduced production cost and low maintenance which have proven to be a main factor in a push towards recycled biocomposites. In this paper we have fabricated a biocomposite model from materials like sawdust, rice husk. The main reason to use biocomposites is that they are more economical and have high strength to weight ratio compared to glass fibers. Hence fabricated material can be used for various applications. [ABSTRACT FROM AUTHOR]

Abstract Glass fibre/epoxy composites are widely used in construction, aerospace, automotive and wind turbine industries. During the manufacturing of glass fibres, they are surface-treated with an aqueous polymeric solution in a process called as sizing. This aqueous sizing composition protects the fibers, eases its handling and facilitates the interaction of fibres and matrix at the interface which affects the mechanical properties of the composites. The present study looks at the effect of a phenomenon called as 'sizing migration' on the strength, stiffness and failure mechanisms under tensile, compressive and inter-laminar shear loads in unidirectional glass fiber/epoxy composites. A detailed study has been performed to elucidate how sizing morphology underlying these glass fibers impact the stress-strain behaviour of the composite. Unidirectional glass fiber/epoxy composites were manufactured using vacuum assisted resin infusion molding process which exhibited a fiber volume fraction of ∼58 ± 2%. From the analysis of the relevant mechanical parameters, an intrinsic correlation between the strength and the sizing migration phenomenon has been deduced and explained on the basis of stress-strain curves under different loading conditions. The present study can help in defining the acceptance and rejection criteria in unidirectional fabrics with sizing migration issues. [ABSTRACT FROM AUTHOR]

Abstract This study investigated the usability of hybrid sandwich structures as facade panels. The explored sandwich structure was made of mineral-glass fibre reinforced polymer (GFRP) skins and a GFRP truss core, fabricated by means of a novel manufacturing method. The compressive and shear specific strengths of the panels were assessed and compared with a few common lightweight structures to verify that the manufactured truss core had comparable values. Three-point bending tests indicated that the polyurethane foam used (required for the manufacturing process) had negligible mechanical contribution. Full-scale panels were tested under a distributed load. The tests were simulated using the three-dimensional finite element method to predict the pressure at which mineral cracks appeared in order to avoid their occurrence in the design phase. The simulation results exhibited good agreement with experimental data, and the model was validated in terms of deflection and strain responses. The occurrence of cracks and their propagation were numerically reproduced using the concrete-damage plasticity model. The link between the connector and crack positions in the mineral skin was highlighted in this study. [ABSTRACT FROM AUTHOR]

Abstract Nonlinear creep behavior of one commercial short glass fiber reinforced polypropylene was investigated using tensile creep tests and stiffness degradation measurements. The impact of thermal aging and following quenching was evaluated on the latter mechanical property. Experimental results were modeled applying nonlinear viscoelastic model used by Pupure et al. (2013) and developed by Lou and Schapery [1,2]. Results showed that this model can describe nonlinear behavior of short glass fiber reinforced polymer composites, where microdamage is given by debonding of fiber-matrix interfaces already at low strains, where cracks propagate and lead to tensile creep fracture. [ABSTRACT FROM AUTHOR]

Abstract The effects on the thermal and mechanical properties of a glass fiber/polyurethane composite for automotive applications exposed to an accelerated aging environment by use of elevated temperatures were assessed in this study. Changes within the material are evaluated in terms of mass variation, and by Dynamic-Mechanical Analysis (DMA), Three-Point Bending (3 PB) tests, and Light Microscopy. Water induces a reversible decrease in glass transition temperature (Tg) due to plasticization of the matrix, while the silicone-based brake fluid (DOT5) slightly improves the mechanical and thermal properties. Significant changes in the material are found when exposed to the glycol-based brake fluid (DOT4) and gasoline, in terms of chemical alterations and delamination. However, the combination of liquids immersion and high temperatures has the most significant impact. The concept of accelerated aging cannot be applied in DOT4 and gasoline since structural changes occur, while in water the prediction made using 'short-term' tests deviates from long-term experimental results. Highlights • Accelerated aging is a good method for rapid identification of the main degradation mechanisms affecting polymer composite. • Structural changes occur in the fiber reinforced polyurethane after exposure to glycol-based brake fluid at 70 °C. • Mechanical properties of composite when exposed to water decrease by water absorption through matrix/fiber interface. • Temperature is the governing factor affecting the mechanical performance. • Increased temperature activates the diffusion of liquids in the composite, thus accelerating its deterioration. [ABSTRACT FROM AUTHOR]

Unveiling the fundamental thermal‐oxidative aging mechanism and thermal degradation kinetics of the poly(decamethyleneterephthalamide) (PA10T)/ glass fiber (GF) composites under different aging temperatures (160°C, 200°C, and 240°C) for 0–50 days will facilitate the understanding of the interaction between matrix PA10T and GF. The results revealed that the decrease of mechanical properties referring to tensile strength, flexural strength and notched impact strength, and the occurrence of debonding phenomenon between PA10T matrix and GF were increasingly obvious after longer aging time at higher aging temperature. At the same time, the decline of crystalline was mainly ascribed to the thermal‐oxidative aging effect, which triggered the deterioration of mechanical properties of PA10T/GF composites. Accordingly, the enhancement of rigidity were probably attributed to the higher temperature aging effect with the aging time prolonging in PA10T/GF composites, while the interfacial debonding between GF and resin matrix obviously occurred with the increase of aging time. In a word, it is believed that investigating the fundamental thermal‐oxidative aging of PA10T/GF composites would be beneficial to optimize and control the service life and applications of materials. POLYM. ENG. SCI., 59:643–656, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Abstract Estimation of the remaining useful life (RUL) based on the elastic strain energy density using the non-contacting and full-field capabilities of Thermoelastic Stress Analysis (TSA) was applied to E-glass fiber-reinforced polymers (GFRPs) subjected to high-cycle fatigue loading conditions. A quantitative prediction was successfully attained during the material's intermediate and final fatigue life phases. The initial state of the specimen was used as the reference data for defining a damage parameter that enabled the detection of visually imperceptible subsurface cracks. [ABSTRACT FROM AUTHOR]

Highlights • This paper deals with the mechanical response of glued in rods. • It takes into account the diameter of rods, the material of rods and the direction of the grain of the timber. • It gives an overview and presents known design models and technical approvals comparing the different approaches. • Comparison between the experimental results and the main equations of the literature review. • The authors propose one equation for the case where the bars are parallel to the timbers' grain. • In addition, another one for the case where the bars are perpendicular to the timbers' grain. Abstract We address the mechanical response of glued in rods, taking into account parameters such as rod diameter, the material properties of the rods (carbon or glass fibre-reinforced polymer), and the grain orientation of the timber (rods parallel and perpendicular to the timber grain). All the experimental setups employ pull-out tests, where rods are glued in only on one side of the specimen, and these tests are assessed at the premises of the Laboratory for Composite Materials and Composite Structures at the University Claude Bernard Lyon I. In addition, we give an overview and present known design models, technical approvals and regulations, national standards, and guidance papers, comparing the different approaches among them and with the experimental results. Good agreement was shown and further useful results were observed. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study is to compare two different standardized testing procedures, tensile testing and Mode-I double cantilever beam (DCB) testing, to evaluate a possible correlation between the dominant failure in glass fibre-reinforced plastics and their according acoustic emissions (AE). AE is processed by using a burst collection of all recorded transient signals and is further analysed with the k-means clustering algorithm. To generate damage related AE, a series of experiments for tensile testing and Mode-I DCB testing is performed on 16-layer glass fibre/epoxy specimens with a cross-ply lay-up for tensile and an unidirectional lay-up for Mode-I DCB testing. Three sensors at tensile testing and one sensor at Mode-I DCB testing gather AE data. The results of clustered burst signals show a good accordance between both testing procedures, with a similar weighted peak frequency (WPF) range in each classified cluster. In total, three different clusters are determined. An assignment of these three clusters to the three dominant damage mechanisms, visually observed by microscopy, is suggested. [ABSTRACT FROM AUTHOR]

A large quantity of resources consumed by the construction industry and the resultant pollution has inspired the need to study eco-friendly materials, such as kenaf fibers, that can be used for construction applications. Kenaf fibers were used to reinforce cement by fabricating fiber reinforced cement composites that exhibited outstanding mechanical and thermo-physical properties. A considerable interest has arisen in investigating the use of natural fiber to replace synthetic fiber for different composite products to alleviate the environmental impact from the traditional construction materials. In order to evaluate the environmental performances of glass fiber reinforced cement wall panels and kenaf fiber reinforced cement wall panels, this study conducted a comparative life cycle assessment (LCA) on the fiber reinforced cement wall panels between kenaf fiber and traditional glass fiber. The structural function and thermal insulation function of the wall panels were considered as two separate functional units. The LCA results showed that the environmental impact could be significantly reduced using kenaf fiber to replace glass fiber as reinforcement in the cement wall panels in regards to both structural and insulation functions. The major contribution to the environmental impact for the fiber reinforced wall panels was from cement and the production of the cement raw materials. Kenaf fiber significantly reduced environmental impact, which can be a viable eco-friendly material to replace glass fiber for the construction industry. [ABSTRACT FROM AUTHOR]

Abstract Nano/micro glass fibril (nGF) was used as a reinforcement material for the modification of epoxy resin with different contents, in which the amino group was introduced initially to the nGF surface via a silane treatment reaction. Composite samples based on untreated nGF filled epoxy were also fabricated for comparison. The effects of these fillers on the characteristics of cured epoxy resin, such as compatibility, curing degree, fracture toughness, mechanical, morphological, and thermal properties, were examined. The addition of amine-functionalized nGF (nGF-NH 2) to the epoxy resin resulted in improvements in their fracture toughness, and mechanical and thermal properties. The fracture toughness, tensile strength, and flexural strength of the epoxy resin in the presence of 0.2 phr nGF-NH 2 were improved by 50.79%, 32.67%, and 28.88%, respectively, compared to the virgin epoxy resin. Scanning electron microscopy revealed a relatively rough surface with shear deformation and tortuous cracks, thereby inducing higher fracture toughness in the nGF NH 2 modified epoxy system. Thermal stability improvement of the epoxy with nGF-NH 2 was also confirmed by thermogravimetric analysis. Highlights • Amine-functionalized nano/micro glass fibrils (nGF-NH 2) were fabricated via a silane treatment reaction. • nGF-NH 2 was introduced into epoxy resin to improve mechanical properties and fracture toughness. • With a 0.2 wt% nGF-NH 2 content, flexural strength, tensile strength, tensile modulus and fracture toughness were improved. • Fracture surface of modified epoxy resin became rougher and tougher than that of pristine epoxy resin. [ABSTRACT FROM AUTHOR]

Self compacting mortars (SCMs) plate specimens with dimension of (500×500×40) mm were cast with three-dimension (3D) textile glass fiber having three diverse thicknesses 6, 10, and 15mm to measure their punching strength. Plates with one and two layers of chicken wires, as well as micro steel fiber of 0.75 % volume fraction were tested under punching for comparison. Punching shear tests have been carried out by applying concentrated load with steel cylinder of 50mm diameter and 10 mm height. The mechanical behavior of SCMs plate was discussed in terms of observed behavior, ultimate load, load - deflection curves, and crack pattern. The results indicated an enhancement in the ultimate load at (28 and 90) day ages by about (7.82% and 24%), respectively. The maximum ultimate load was increased by about (58.4 and 54.1) % for plates reinforced by micro steel fiber at 28 and 90 days, respectively as compared with reference. The maximum deflection at the center of the Self-compact mortars plates for all tested plates was improved. [ABSTRACT FROM AUTHOR]

High performance polypropylene/glass fiber (PP/GF) composites were prepared by introducing different percentage of maleic anhydride- g -polypropylene (MPP) and epoxy resin (EP) in the matrix. The coupling effect of MPP and EP on the mechanical properties of the hybrid composites were highlighted and the complicated reinforcing mechanism were discussed in detail. Even though the addition of MPP could apparently improve the performance of composites, as the EP coupled especially at higher MPP and EP content, both the tensile and impact strength get further enhancement. For the sample with 10 wt% MPP and 10 wt% EP (10MPP/10EP), the tensile and impact strength show significant enhancement by 136% and 171%, respectively, compared to the control PP/GF composite. It is demonstrated that the good compatibility among each constituent as well as the reaction between EP and MPP, which could efficiently facilitate the network formation, contribute to the high performance of the composites. The finer EP particles caused by the enhanced compatibility as nucleating agent could promote the crystallization, but the crystallinity of the composites does not change so much. A schematic mechanism of the interfacial structure on both molecular and microscopic levels is depicted, where the reaction between MPP and EP are considered as a dominated factor to influence the above-mentioned network formation. This local network structure causes the composites as an integrate showing excellent mechanical performance. [ABSTRACT FROM AUTHOR]

This paper presents an optimised material extrusion (MEX) 3D printing method with feedstock produced from glass fibre reinforced polypropylene (GFRPP) composite waste and investigates the effect of glass fibre weight fraction (0%, 15%, 30%, 40%) on the printability and mechanical properties of filaments and printed specimens. GFRPP feedstock filaments were fabricated by optimising the filament extrusion process parameters. The highest ultimate tensile strength (112 MPa) was obtained in a filament with 40% fibre weight content. In addition, repeated recycling of filament was shown to reduce the fibre aspect ratio and enhance the filament quality. It was shown that the increase in glass fibre content from 0% to 40% improved the ultimate tensile strength of MEX 3D printed specimens from 14.7 MPa to 23.4 MPa as well as the flexural strength of MEX 3D printed samples from 11.68 MPa to 66.55 MPa. The increase in fibre weight content from 30% to 40% had a minimal effect (+1%) on the ultimate tensile strength of the printed samples. In addition, the 40% filaments exhibited a more brittle behaviour, rendering them less suitable for MEX 3D printing than 30% GFRPP. The results showed that waste industrial GFRPP material can be effectively enhanced and converted to short fibre reinforced material extrusion filament feedstock for the printing of components as a circular economy demonstrator. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, the effect of salt-fog exposition on the mechanical behavior of sandwich panels having cork agglomerate core was investigated. In particular, the aim of this research work is to assess the shield function of unidirectional basalt and E-glass reinforced polymer on the aging and failure mechanism of the core when such class of material are destined to operate in hostile environments (e.g., marine environment). To do this, the manufactured sandwich panels were exposed up to 60 days to salt-fog environment, according to ASTM B 117 standard. Unaged and aged specimens were analyzed through three point bending tests after aging time of 10, 25 and 60 days. Digital Image Correlation (DIC) was carried out to perform a strain field analysis of the longitudinal cross-sections. The differences in the mechanical behavior of the synergistic cooperation of the cork core with basalt and glass fiber were highlighted thorough this technique. Moreover, the failure mechanisms related to each combinations for different aging times were described. The experimental results showed that, the intrinsic conditions of the composites (e.g., presence of defects, poor fiber-matrix adhesion), that are strictly linked to the fiber-matrix compatibility and to the impregnation quality, may induce to differences in the local mechanical behavior of the sandwich panels and to a faster aging process of the cork core in the case of basalt fiber skinned sandwich, especially in the first phases of the exposition. [ABSTRACT FROM AUTHOR]

This paper aims to present a methodology to predict the anisotropic and non-linear behaviour of glass fibre reinforced plastics using finite element methods. A material model is implemented in order to remedy the need of multiple material definitions, and to control the local plastic behaviour as a function of the fibre orientation. Injection moulding simulations traditionally provide second order orientation tensors, which are considered together with a homogenization scheme to compute local material properties. However, in the present study, fourth order tensors are used in combination with traditional methods to provide more accurate material properties. The elastic and plastic response of the material model is optimized to fit experimental test data, until simulations and experiments overlap. The proposed material model can support design engineers in making more informed decisions, allowing them to create smarter products without the need of excessive safety factors, leading to reduced component weight and environmental impact. [ABSTRACT FROM AUTHOR]

The objective of this study was to produce the hybrid carbon/fiberglass composite laminates, to characterize their mechanical properties under room temperature and to evaluate the effect of nanoclay addition into epoxy matrix on the mechanical properties of the hybrid composites. During fabrication of fiber reinforced polymer composites, the organo modified nanoclay (0%, 0.5%, 0.75%, and 1.25% of nanoclay reinforcement by weight) was mixed with epoxy system using an ultrasonic mixer. The produced matrix was then applied onto fibers by using hand layup method. Mechanical tests were performed to investigate the effect of nanoclay content on tensile and flexural properties of the fabricated hybrid carbon/fiberglass composites. The tensile and three point bending tests were performed according to ASTM D3039 and ASTM D7264, respectively, to measure the highest tensile strength, modulus of elasticity and bending modulus of the hybrid laminates. Experimental results show that the tensile and flexural performance of hybrid carbon/fiberglass composites was changed with the nanoclay content. [ABSTRACT FROM AUTHOR]

Fiber Reinforced Polymers (FRP) material are proposed and implemented for civil engineering applications for both retrofitting of existing structures and building of new facilities. In new construction realizations, FRP elements are frequently manufactured using pultrusion that represents a high rate manufacturing method, however characterized by a prevalent longitudinal fiber orientation with consequently weakness along the directions different than the longitudinal one. The intrinsic orthotropy, the presence of defects due to the manufacturing processes and the brittle failure mechanisms are peculiarities that decelerate their wide applications, so that are an open issue to be solved. In this regard, the present work experimentally investigates the local behavior of a commercial Pultruded I-shaped Glass FRP (PGFRP) element, in order to: 1) evaluate the mechanical properties of the material according to different fiber orientations, 2) check the validity of the Tsai Hill Criterion and 3) investigate the capacity of the web-flange (WF) junction, that is a recognized weak point, through a novel and simple experimental test. [ABSTRACT FROM AUTHOR]

For short fiber reinforced plastic parts the local fiber orientation has a strong influence on the mechanical properties. To enable multiscale computations using surrogate models we advocate a two-step identification strategy. Firstly, for a number of sample orientations an effective model is derived by numerical methods available in the literature. Secondly, to cover a general orientation state, these effective models are interpolated. In this article we develop a novel and effective strategy to carry out this interpolation. Firstly, taking into account symmetry arguments, we reduce the fiber orientation phase space to a triangle in R2. For an associated triangulation of this triangle we furnish each node with an surrogate model. Then, we use linear interpolation on the fiber orientation triangle to equip each fiber orientation state with an effective stress. The proposed approach is quite general, and works for any physically nonlinear constitutive law on the micro-scale, as long as surrogate models for single fiber orientation states can be extracted. To demonstrate the capabilities of our scheme we study the viscoelastic creep behavior of short glass fiber reinforced PA66, and use Schapery’s collocation method together with FFT-based computational homogenization to derive single orientation state effective models. We discuss the efficient implementation of our method, and present results of a component scale computation on a benchmark component by using ABAQUS ®. [ABSTRACT FROM AUTHOR]

This study has been carried out to show the use of natural fibres as the potential substitute of synthetic fibres in tribo-composites. The abrasive wear behaviour and mechanical properties of waste sisal/glass, sisal/carbon hybrid fibre reinforced polypropylene (PP) composites were analysed in this study. Results showed that increasing the sisal fibre weight content in the composites increases the coefficient of friction. The abrasion volume of sisal/glass hybrid composites showed significantly lower than those of sisal/carbon hybrid composite for the same hybrid ratios. This means that addition of sisal fibres on waste carbon and glass fibre reinforced PP composites decreased the potential of tribological performance. Although adding of sisal fibres as a natural substitute fibre source to waste short carbon fibre composites lead to inferior properties, an addition of sisal fibres to waste glass composites shows lower densities, comparable mechanical and abrasion volumes than that of waste glass fibre composites. This shows that sisal fibres can be used in place of glass fibres. The scanning electron micrographs of the fracture surfaces show that the wetting interaction of sisal and glass fibre with PP matrix is better than those of the sisal carbon hybrid composites. Furthermore, the worn surfaces of the sisal and its hybrid composites show vertical cracks, loose fragments, micro ploughing and transfer layers. [ABSTRACT FROM AUTHOR]

3D woven glass fibers sandwich panels have become the focus of interest due to their inherent light weight and, thus, their remarkable stiffness. However, a question is that whether their hollow galleries could be filled with still light materials which even at the same time contribute to their mechanical performance. This work examines the effect of porous polymer nanocomposites filling galleries of such panels on mechanical response of newly formed hybrid composites. To achieve this, the nanocomposites of natural nano-structured zeolite/polyurethane foams were fabricated and injected within 3D woven glass fibers sandwich panels. Mechanical characterization techniques including the flatwise compression, edgewise compression, three-point bending and drop weight impact were carried out to understand the effect of addition of the reinforced foam on the mechanical response of the specimens. It is shown that the polyurethane foam reinforced with natural nano-structured zeolite particles significantly improves the flexural strength, ultimate load and energy absorption of the filled composite sandwich panels. It is also demonstrated that the damage and local wrinkling failure compared with other typical sandwich panels do not occur due to the presence of the glass fiber yarns vertically located between panel sheets. These type of composites provide high specific strength results from high-performance and low-density structure. [ABSTRACT FROM AUTHOR]

This study investigates the impact behavior of fiber-metal laminates (FMLs) (Carbon FMLs and Glass FMLs), which were fabricated by using high-stiffness steel, carbon prepreg, and glass prepreg through autoclave molding. The mechanical behavior of the FMLs was evaluated by performing tensile, compressive, in-plane shear, and low-velocity impact tests. Drop-weight impact tests were conducted to induce cracking of the FMLs, and the crack initiation along with crack propagation behavior of the different laminate sequences ([0/0], [0/90], [0/90/0], [90/0/90] and [0/90/90/0]) were also studied. The results show that the fabricated FMLs have higher strength and stiffness than conventional FMLs. Their impact strengths increased, and weights decreased simultaneously. The absorption energy was proportional to the crack length that was induced by the low-velocity impact. Moreover, it was found that the fiber orientation mainly affected the direction of crack propagation in the FMLs. This investigation facilitates the design of high-stiffness and lightweight FMLs for automotive parts. [ABSTRACT FROM AUTHOR]

Polyetheretherketone (PEEK) and two types of short-fiber (carbon fiber and glass fiber) reinforced PEEK were investigated under uniaxial tensile tests of various strain rates. The strain rate varies in the range between 10 −3 and 10 3 s −1 . The paper aims to show the rate dependency of mechanical properties of short-fiber reinforced PEEK, and the relationship between its failure behavior with strain rate and fiber type. High-speed camera system and digital image correlation technique were employed to measure the evolution of strain distributions. Scanning electron microscopy (SEM) was introduced to examine and analyze the failure mechanisms. The results indicated that the ultimate stresses of PEEK and PEEK composites presented little sensitivity against strain rates, while the failure strain of pure PEEK decreased and the failure strain of PEEK composites increased apparently with the increase of strain rate. Also, carbon fiber reinforced and glass fiber reinforced specimens showed differences in sensitivity to strain rate and failure mechanisms, the latter of which is further confirmed by in -situ SEM tensile tests. [ABSTRACT FROM AUTHOR]

Corrosion attack due to chloride ions is a major problem found in steel reinforced concrete structures when subjected to marine environment. Glass fiber reinforced polymer (GFRP) has become an alternative reinforcement in marine concrete structures due to its excellent corrosion resistance, making it possible to combine with concrete composed of seawater and sea sand. However, the knowledge on the short-term and long-term properties of GFRP reinforced concrete columns is still limited. In order to facilitate the practical application of GFRP reinforced concrete in marine environment, the effect of chloride ions on the structural behaviors of GFRP reinforced concrete columns is investigated here. Numerous specimens consisting of GFRP reinforced concrete columns and steel reinforced concrete columns with different chloride concentrations were fabricated, conditioned and tested. The test results show that GFRP reinforced concrete columns cast with saturated water suffer a deterioration of 27.9% in load carrying capacity, but possess an enhancement of 104% in ductility when compared to those of specimens cast with distilled water. Meanwhile, it is observed that the GFRP reinforced concrete column possess a ductile failure mode, which indicates that the GFRP spirals can provide an effective confinement to the concrete core even in high chloride environment for a prolonged time. Such findings provide solid evidence to the feasibility and application of GFRP reinforced concrete in the offshore structures or artificial islands with great environmental and economic benefits. [ABSTRACT FROM AUTHOR]