Effect of CFRP plate length on flexural behavior of GFRP reinforced concrete beam strengthening

This research investigates the effect of CFRP plate length on flexural behaviour of GFRP strengthened reinforced concrete beam. CFRP plate was placed on the bottom of the beam to act as tension reinforcement. Ten beams were tested, largely divided into over designed and under designed reinforced beams. Each group had one steel reinforced concrete beam, one GFRP reinforced concrete beam and three GFRP reinforced concrete beam with different length of CFRP plate at the bottom of beam. Tested parameters included flexural strength, stress–strain relationship and deflection. Results indicated that all strengthened beams had improved structural performance where the maximum flexural strength increased by 102% and maximum deflection reduced by 35%. The CFRP plate can significantly improve the load-bearing capacity of strengthened GFRP concrete beams

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

Characterisation and effects of the Effective Micro-organics (EM) and Industrial Waste (IW) materials as a partial mixture in concrete

Researchers keep renewing and updating the concrete technology from day to day. There are a lot of added materials in concrete mixture. The main objective in this study is to investigate the admixture or filler that are economical, environment-friendly, sustainable, and easily obtained. This research focused on two type of material which is locally produced that is material based on Effective Microorganisms (EM) and Industrial Waste (IW) which are used as a partially in concrete mixture. The scope of study only focused on laboratory work to obtain the results. The result indicated in that the application of 10%, 20% and 30% of EM in concrete mixture, can be applied in concrete technology and improve the concrete properties while the application of IW in this study indicated the reduction in concrete properties as the content of IW increased and showed that it cannot replace the conventional material in concrete mixture as filler. This study recommend to extend the research especially concrete containing IW that heated in high degree of temperature (above 500 oC) because this study indicated it was improved the concrete properties on 500 oC. The outcome of the study has developed of new technology in achieving sustainability for affordable concrete structure

Flexural behavior of GFRP RC beam strengthened with carbon fiber reinforced polymer (CFRP) plate: cracking behavior

There has been much research conducted on the current performance of Fiber Reinforced Polymer (FRP) as reinforcement. It was due to FRP easier to maintain than steel during construction because of less weight. Laboratory works on the flexural behavior of concrete beams that with GFRP and CFRP use as a plate strengthening for the beam size 2800 x 200 x 250 millimeter. study of the pattern of cracking and failure modes of the beam will be compared between the ten types of beams consisting of steel reinforced beams , beam-reinforced GFRP and GFRP reinforced beams strengthened with CFRP with different lengths. Comparing between the beam bending performance was examined through the ultimate load, cracking and failure modes

A Review of Structural Performance of Oil Palm Empty Fruit Bunch Fiber in Polymer Composites

According to environmental concerns and financial problems, natural fibers have become interesting and fascinating nowadays to be used as an industrial material and structural material for rehabilitating of structures. Oil palm empty fruit bunch fiber (OPF) is a natural fiber which is found a lot in tropical areas. Scientists have used OPF fiber with many types of resins such as epoxy, polypropylene, polyester, and phenol formaldehyde. Therefore, this paper focused on the properties of OPF fiber and gathered mechanical properties of OPF composites (OPF as reinforcement of polymer) reported by other researchers in terms of tensile and flexural properties. Furthermore, the chemical surface modification methods to solve the interfacial bonding of fiber and polymer were mentioned. In addition, the results of hybrid composites of OPF were also discussed in this paper. Meanwhile, the results of composites were compared to pure resin properties and also the stress-strain diagram and internal strain energy of composites were considered. Besides, the effects of adding OPF to other composites to make a new hybrid composite were indicated. Finally, it is clear that the use of oil palm fiber composites for structural elements for bearing loads is not recommended but the usage of OPF composites for secondary structural elements may be recommended due to future researches

Characteristics of continuous unidirectional kenaf fiber reinforced epoxy composites

Kenaf fibers generally has some advantages such as eco-friendly, biodegradability, renewable nature and lighter than synthetic fibers. The aims of the study are to characterize and evaluate the physical and mechanical properties of continuous unidirectional kenaf fiber epoxy composites with various fiber volume fractions. The composites materials and sampling were prepared in the laboratory by using the hand lay-up method with a proper fabricating procedure and quality control. Samples were prepared based on ASTM: D3039-08 for tensile test and the scanning electron microscopy (SEM) was employed for microstructure analysis to observe the failure mechanisms in the fracture planes. A total of 40 samples were tested for the study. Results from the study showed that the rule of mixture (ROM) analytical model has a close agreement to predict the physical and tensile properties of unidirectional kenaf fiber reinforced epoxy composites. It was also observed that the tensile strength, tensile modulus, ultimate strain and Poisson's ratio of 40% fiber volume content of unidirectional kenaf fiber epoxy composite were 164. MPa, 18150. MPa, 0.9% and 0.32, respectively. Due to the test results, increasing the fiber volume fraction in the composite caused the increment in the tensile modulus and reduction in the ultimate tensile strain of composite

Tensile properties of kenaf fiber due to various conditions of chemical fiber surface modifications

Nowadays, due to environmental concerns and financial problems of synthetic fibers, natural fibers or bio-fibers are interesting to be used as reinforcement fibers in polymer composites for structural elements and construction materials. Chemical surface modification method is a well-known method to increase the interfacial bonding strength between fibers and polymer matrix. The alkaline treatment of kenaf fiber may affect not only the surface but also the texture of fiber resulting in the variation of the mechanical and physical properties. This study was conducted to find out the effects of different conditions of alkaline treatment in terms of the concentration of alkali solution and immersion time on the fiber properties. For this study, 360 fiber specimens were tested for 24 various conditions of initial treatment and alkaline surface modifications. Then, the results were analyzed and reported by using of three methods including regression method, averaging the data and system compliance method. Besides, the scanning electron microscopy was employed to observe the specimens’ appearance, fracture area and fibers’ diameter. Result from the study found that the average diameter of untreated kenaf fiber was 67.6 μm, the density was 1.2 g/cm3 and the tensile strength was 780 MPa. Moreover, the 5% alkali solution was the best for kenaf fiber treatment because of causing no tension on the fiber texture and structure as compared to 10% and 15% alkali solution

Durability performance of green concrete composites containing waste carpet fibers and palm oil fuel ash

Cleaner production is a pressing concern of the 21st century. Waste materials resulting from different industrial processes requires proper management to ensure a cleaner environment. The use of recycled materials in new green concrete production is very attractive due to the low-cost related to the waste materials in addition to saving required space for landfill purposes and the development as well as improvement in the concrete properties. This paper focuses on the durability properties of green concrete composite, which comprised of waste polypropylene (PP) carpet fiber and palm oil fuel ash (POFA). Properties studied include slump and VeBe time of fresh concrete as well as water absorption, sorptivity, chloride penetration, carbonation, and drying shrinkage of hardened concrete. Carpet fiber of 20 mm in length and six volume fractions of 0e1.25% were used with ordinary Portland cement (OPC). Another six concrete mixes were cast whereby OPC was replaced by 20% POFA. It was observed that the combination of PP carpet fiber and POFA decreased the slump values and increased the VeBe time of the fresh concrete mixes. In addition, water absorption, sorptivity, chloride penetration, and carbonation depth of the concrete composite for both OPC and POFA content mixtures were reduced with the addition of carpet fiber, with volume fractions of up to 0.75%. The positive interaction between carpet fibers and POFA subsequently led to the lower drying shrinkage of the concrete composite. The influences of POFA on the durability performance of concrete was observed to be more significant at longer curing periods. The findings of the study demonstrated that there is a promising future for the use of waste carpet fibers as a fibrous material in the production of a green and durable concrete. Green concrete also minimizes solid wastes, improves air quality, and leads to sustainable cement and concrete industry