Performance of carbon fibre reinforced polymer plate bonding system under various environmental conditions

The use of Carbon Fiber Reinforced Polymer (CFRP) as strengthening material for reinforced concrete and steel has been a focused of many researched around the world. Superior properties of the CFRP plate including lightweight, high tensile strength, and corrosion resistance make it a favorable material in strengthening of existing structures. The CFRP strengthening technique has been known to enhance the structural performance of the strengthened member. However, one of the main drawbacks is the long-term durability of the CFRP bonding system against various environmental conditions. This study evaluates the durability performance of the CFRP plate bonding system exposed to different environments. Experimental work was conducted in which the CFRP plate, adhesive coupons, and CFRP double lap shear samples were prepared and subjected to either continuous or wet-dry cycles in different exposures including plain water, salt water, acidic solution, and outdoor. The exposed samples were tested at different ages. The study found that the CFRP plate was quite durable and the change on the properties was negligible. However, the results indicated that exposure to different environments had affected the adhesive strength properties significantly with exposure to salt water was found to have the most degradation effect on the adhesive

A study on the application of solar cells sensitized with a blackberry-based natural dye for power generation

This research paper is aimed at evaluating the use of natural dyes from blackberry (Rubus glaucus) obtained naturally for their subsequent application in laboratory solar cells to place them in dye-sensitized solar cells (DSSC) for the generation of electrical energy. The problem of the study is the high demand generated by global warming. Natural dyes were used to sensitize six solar cells, which were tested for their ability to absorb ultraviolet and visible light using a spectrophotometer in the ultraviolet-visible range, a solar simulator, and a current-voltage tester. The voltmeter was used to show how much energy each solar cell emitted over eight to 18 hours of daylight, with a required absorbance of 400-500 nm using six solar cells that had been sensitized with natural dyes. To reduce the high demand generated by global warming, use natural dyes from plant species as a supplement to improve efficiency in capturing renewable energy (solar) and converting it into electrical energy. Blackberries are lyophilized and then macerated for one day at room temperature in a dark, cool place to maximize dye's absorption. With two electrodes, the photo and contra, and an electrolyte in between, a Gratzel-type DSSC can be built. Using the doctor blade technique, the titanium dioxide film is added to the fluorine-doped tin oxide (TiO2) in the photoelectrode. By immersion, a natural colourant is then applied. TiO2 glass with a platinum film deposited on it serves as the counterelectrode

Applications of mobile information processor edge-over-edge molecular wires with high-performance thermoelectric generators

If high-efficiency organic isotherm models for mobile processors can be found, a variety of energy harvesting devices, such as Peltier coolers composed of flexible and transparent thin-film materials, might be manufactured. The thermoelectric characteristics of three zinc porphyrins (ZnP) were studied. Theoretical analyses of electron transport across a potassium (Zn-Diphenyl porphyrin: Zn-DPP) molecular sandwiched between electrode surface with three distinct connections were investigated. The contribution of this research is to see what happens because once pyridine is added above the surface of the zinc-porphyrin skeleton, the "edge-over-edge"dimer created from stacked formed rings has a high electrical conductance, minimal exciton thermal conductance, and a large thermal diffusivity on the order of 300 V K1. At room temperature, these variables add up to a projected ZT 4 figure of merit, the greatest ZT for a single organic molecule ever seen. The stacked arrangement of the porphyrin rings causes low phonon thermal conductance, which delays phonon transport across the edge-over-edge molecule and increases the Seebeck coefficient, resulting in a higher ZT value

Modulus Effect on Local Load Distribution for FRP/Steel Bonded Joint

Rehabilitation of piping system has been a major concern in the oil and gas industries. Fibre reinforced polymers (FRPs) have been introduced as an alternative approach and increasingly used in repairing oil and gas pipeline. However, performance of pipeline repair system is decided by its load transfer ability and for FRPs, this led to the debonding issue which has been studied by many researchers. This paper describes a series of double strap shear tests under tensile load to investigate the bond performance between FRP sheets and steel plates. Adhesive failure at the steel-adhesive interface was observed to be the dominant failure mode for both glass fibre reinforced polymer (GFRP)-Steel and carbon fibre reinforced polymer (CFRP)-Steel DSJ due to its higher modulus ratio compare to FRP-adhesive interface. Strain distribution along the bond length shows that GFRP offer larger extension before debonding compared to CFRP. CFRP-Steel DSJ withstand higher ultimate load and possessed better load transfer ability compare to GFRP-Steel DSJ. The load spread throughout the CFRP-Steel DSJ bond length while only 50% of GFRP-Steel bond length were effective. The experimental result shows that the FRP type and bond area of a rehabilitated pipeline need to be taken into consideration during pipeline strengthening

Review on tin slag polymer concrete as green structural material for sustainable future

Ordinary Portland cement concrete (OPC) is widely utilized in construction industry as structural material, but it has environmental issue due to natural resources consumption and Carbon emission. Therefore, polymer concrete (PC) with tin slag (TS) waste are introduced to replace aggregate and cement in OPC. Previous research on potential to apply TSPC as structural material has provided compressive strength data which shows that it can compete with OPC. PC using polyester and 100% TS aggregate with resin-aggregate ratio 30:70 consist of fine (<1 mm) uniformly graded aggregate has achieved compressive strength 58.21 MPa. After that, in another study, gap graded performance of TSPC using raw (4 mm) and coarse (2 mm) TS aggregate introduced and result in compressive strength 37.71 MPa, highest compared to other variation. By applying external FRP strengthening with two layers of CFRP increase strength to 125.07 MPa and finally uniformly graded TSPC with three layers of CFRP wrapping increased strength to 156.88 MPa. This discovery has contributed to the beginning of active study in TSPC as green structural material for sustainable future

A review of properties and fabrication techniques of fiber reinforced polymer nanocomposites subjected to simulated accidental ballistic impact

Composite structure experience ballistic or high velocity impact loading during in-flight operations owing to hail, bird and debris strike. In thin laminates, such an impact entails damage resulting from complex interplay of projectile characteristics, composite material properties and environmental conditions. Delamination resistance and energy absorption are two parameters to characterize the ballistic performance of materials in research community. As out of plane properties are controlled by matrix, its microstructural modification is the primary method through which ballistic performance of composites are sought to be improved. High specific surface area nanoparticles are now being used, for matrix modification, to induce nano-scale toughness mechanisms. This paper starts with brief outline of these mechanisms followed by summarizing nanocomposite fabrication techniques and ballistic impact performance of nanocly, graphene, carbon nanotube and other miscellaneous nanoparticle reinforced composites. Finally, it highlights unexplored areas in polymer nanocomposite research with focus on ballistic performance

Potentiality of MWCNT on 3D-printed bio-inspired spherical-roof cubic core under quasi-static loading

Sandwich panel is increasingly used as lightweight energy absorbing components, which provides excellent crashworthiness performance with the three-dimensional periodic core. This paper investigates 3D-printed bio-inspired spherical-roof cubic cores with multi-walled carbon nanotubes (MWCNT) and foam-filled cores under quasi-static loading. The proposed bio-inspired spherical-roof cubic cores with 1.5 mm wall thickness were manufactured using the fused filament fabrication process, which used 70% polylactic acid (PLA) and 30% carbon fiber filament. Moreover, four groups of 3D-printed bio-inspired spherical-roof cubic cores were compared and analyzed on compressive properties and failure behavior. Experimental results were shown that foam-filled double bio-inspired spherical-roof cubic core with MWCNT was the maximum Fpeak with 1.92 kN, which provided a much more stable plateau load and better energy-absorbing characteristics. In addition, it is conducted that a double bio-inspired spherical-roof cubic core with four notches core is considered as the potential energy-absorbing core

A focused review of short electrospun nanofiber preparation techniques for composite reinforcement

Short nanofibers have been of interest in preparing 3D porous structures, aerosol filters, and nanocomposites. These materials require nanofiber retrieval and application in short form with simultaneous control over aspect ratio. Electrospinning, conventionally, offers minimal control over short nanofiber yield as nonwoven mat is the default configuration of collected sample. High surface area to volume ratio nanofiber, however, can offer new vistas in material design if standardization of short nanofiber preparation practices, offering control over aspect ratio, can be attained. It will provide novel insights into design of tissue engineering scaffolds, filtration membranes, and nanocomposite properties. This work summarizes reported efforts to prepare short nanofiber through mechanical, chemical, material, and operational variables. It aims to provide comparative glance at attempts to control aspect ratio along with pros and cons of the adopted techniques. Lastly, discussion shares generalized conclusions and insights gathered while reviewing material and operational variables adopted for short nanofiber preparation

Bond performances between CFRP plate and steel plate to concrete prism using structural adhesives

Repair and rehabilitation of existing structures is a necessity compared to impractical application by direct replacement of the structures. Repair using steel plates to concrete structures had been seen as the most popular method but these techniques had drawn many problems at sites. Recent application of repair and rehabilitation involved externally bonded reinforcement that causing interface performance as an interesting area to be studied. Performance of epoxied system in externally bonded plates needs to examine more to improve database in literature. This study is required to discover the behaviour of interfacial bond in epoxied based. Bonding of external plate to concrete surfaces using adhesive is a practical solution for upgrading the existing reinforced concrete structures. This paper focuses on the bonding performance of epoxy resin adhesives to CFRP-concrete and steel-concrete prisms. Concrete prisms size of 100 × 100 × 300 mm with roughened surface on both sides was prepared. Surface preparation of the concrete prisms was carefully made prior to bonding to CFRP plates and steel plates respectively. Two groups of specimens, namely CFRP Plate-Epoxy-Concrete Prism and Steel Plate-Epoxy-Concrete Prism, were prepared and tested by applying direct tensile loads until failure. The strain distribution along the bond length of the CFRP Plate-Epoxy-Concrete Prism was fairly linear but with further increase of loads, the local strain became non-uniform and non-linear. The strain distribution along the bond length for Steel Plate-Epoxy-Concrete Prism was almost linear, i.e. proportional to the applied load and uniform. The specimen did not failed at the bonding region but failed due to yielding of steel plates. Result from direct tensile test of the steel plates had drawn to conclusion that the strength of steel plates used for this study was not sufficient in term of strength. The test results showed that structural type of epoxide resin was suitable to be used as structural adhesive. The bonding strength was affected by the length of the bonding surface, modulus of elasticity of the materials and interfacial conditions. It is proven by the better performance from CFRP-prism samples with 283.2MPa local bond stress maximum differences if compared with the Steel-prism. Stress concentration was quite close at bond length of 15mm to 35mm. The stresses decreased gradually from bond length of 65mm to 155mm. The longer or wider the bonding surface, the stronger the bonding strength would be but had to be limited to effective bond length of 60 mm to 120 mm of bond length

Experimental study on tin slag polymer concrete strengthening under compression with metallic material confinement

Studies on the external strengthening of tin slag polymer concrete by fibre-reinforced plastic confinement have provided strength enhancement of tin slag polymer concrete up to 128% with carbon fibre-reinforced plastic confinement. However, the effect of metallic material confinement has yet to be studied. This article presents the experimental finding on tin slag polymer concrete strengthening through metallic material confinement under compressive loads. Machined mild steel metal tube has been employed to strengthen tin slag polymer concrete core in partial and fully confinement prior to compression testing. Through this study, compressive strength of tin slag polymer concrete short column has been enhanced with the metal tube confinement application from 59.19 MPa (unconfined) to 95.86 MPa (partial metal confinement) and 131.84 (full metal confinement) representing 61.95% and 122.74% of strength enhancement percentage. Material behaviour analysis through stress versus strain curves has revealed that the strain softening curve is modified by metal tube confinement before a fracture occurs on both partial and full metal confinement samples compared to the control sample (unconfined). In addition, the failure modes have indicated that the high ductility of metallic confinement material has effectively confined tin slag polymer concrete from sudden fracture where the metal tube in partial confinement indicates ductile expansion while the metal tube in full confinement has shown ductile crushing. In general, it was concluded that metallic material confinement on tin slag polymer concrete under compressive load has resulted in providing strength enhancement and modified the failure mode of tin slag polymer concrete. Finally, further research is recommended, especially by initiating numerical analysis to facilitate parametric studies on tin slag polymer concrete for structural material design