Carbon Reinforcement Research Articles

Development and Mechanical Characterization of Rice Bran Carbon Reinforced Polypropylene Composites

Development and Mechanical Characterization of Rice Bran Carbon Reinforced Polypropylene Composites

Fibre-Reinforced Geopolymers (FRGPs) as Inorganic Composites for Flexural Strengthening of Brick Masonry

ABSTRACT This study presents an assessment of externally bonded Fibre-Reinforced GeoPolymers (FRGPs) as strengthening material for masonry structures. Geopolymer matrices can also potentially fulfil the requirements of restoration criteria for historical buildings, with heat-resistant performances generally better than Fibre-Reinforced Polymers (FRPs). Four FRGPs, embedding either unidirectional steel or bidirectional carbon, basalt or glass mesh as reinforcement, were tested by means of local shear and bending tests on fired clay brick specimens, either alone or coupled with hydraulic lime mortar. In addition, the behaviour of each reinforcement exposed to alkaline environments was investigated through tensile tests on coupons. Results confirmed the interesting potential of FRGPs for strengthening masonry elements, highlighting a good performance of steel and carbon reinforcements.

Material‐minimised construction with extruded textile reinforced concrete

AbstractThe use of textile reinforced concrete (TRC) is particularly suitable for producing sustainable, material‐minimised components, as it allows for a significant reduction in the amount of concrete cover required compared to steel reinforced concrete (SRC). Instead of steel, fibres made of glass, aramid or carbon are used as reinforcement, which are processed from rovings into textiles with a polymer or mineral impregnation. Among these, carbon reinforcements have the highest tensile strength and alkali resistance, making them the most durable in concrete and requiring less maintenance over time. An innovative approach is the production of TRC structures by means of extrusion, in which the stiff, fresh concrete is continuously pressed through a shaping mouthpiece, giving the product its final shape. Within the scope of the CRC/Transregio 280, a new mouthpiece was developed that enables the horizontal introduction of stiff, impregnated textiles. The carbon TRC produced in this process showed a textile stress of up to 4,000 MPa. Additionally, solutions are presented that allow the characterization of stiff, fresh concrete and technical limits for shaping fresh, extruded TRC elements. The potential of this new production method is illustrated through the example of a compound component made of extruded TRC elements.

Dowel action of textile CFRP shear reinforcement in carbon reinforced concrete

Composite structures with textile CFRP (carbon fibre reinforced polymer) reinforcement are characterised by high compressive and tensile strength and have great potential for use in thin-walled structures such as shell structures or girder webs. However, the stress transfer mechanisms activated along cracks of carbon reinforced concrete (CRC) membranes have not been sufficiently investigated yet. Especially the potential of CFRP yarns to transfer shear across sliding crack surfaces has not been thoroughly understood.For steel reinforced concrete elements, dowel action has been studied for several decades and numerous constitutive laws for the shear contribution of dowel action have been developed. In contrast, the sensitivity to transverse pressure of CFRP reinforcement is expected to have a significant influence on the activation of dowel action in cracked CRC. Neither the damage and fracture of impregnated textiles due to transverse compression nor the shear-induced delamination of reinforcement in the vicinity of cracks have been investigated in detail. Therefore, suitable constitutive laws to describe the dowel effect of CFRP reinforcement are not available.This paper presents dowel tests with textile CFRP shear reinforcement and highlights the phenomenology of dowel behaviour in carbon reinforced concrete as well as the main factors influencing the dowel behaviour.

Digital Prefabrication of Lightweight Building Elements for Circular Economy: Material-Minimised Ribbed Floor Slabs Made of Extruded Carbon Reinforced Concrete (ExCRC)

Digital Prefabrication of Lightweight Building Elements for Circular Economy: Material-Minimised Ribbed Floor Slabs Made of Extruded Carbon Reinforced Concrete (ExCRC)

Construction of polydopamine functionalized porous carbon network structure in polymer composites for excellent mechanical and electromagnetic interference shielding properties

Structural and functional integrated lightweight polymer-based composites with excellent mechanical and electromagnetic interference (EMI) shielding properties are urgently demanded in the field of advanced aerospace field. Effective design to construct the interfacial porous microstructures is crucial yet remains highly challenging for maximum EMI shielding effectiveness (SE) while improving the strength of composites. Herein, novel interfacial continuous network structures are constructed based on the in-suit synthesis of porous carbon network on the carbon fibers and chemical functionalized with polydopamine (PDA) to achieve simultaneous improvement of mechanical properties and EMI SE. Results indicate that the construction of active porous carbon networks significantly improves the surface activity and wettability of carbon fibers, which is conducive to enhancing the interfacial strength of the composites. Owing to the synergistic effect of physical enhancement for porous carbon and chemical reinforcement for PDA, the bending strength of the modified composite reaches 138.9 MPa, and the wear rate decreases by 82.9 %, demonstrating excellent mechanical properties. It is worth noting that the EMI SE reaches more than 62 dB in the X-band when the thickness of the modified composite is only 0.4 mm, showing excellent EMI shielding performance. Most importantly, this study provides solid basic knowledge of the interfacial structure design of composites, which is favorable for obtaining expected mechanical and EMI shielding performances and offers strong potential for applications in structural components of the aerospace and electronic equipment field.

Comprehensive analysis of 3D printed PA6.6 and fiber‐reinforced variants: Revealing mechanical properties and adhesive wear behavior

AbstractWhile 3‐dimensional (3D) printing technology is advancing rapidly, commonly used filament materials are struggling to meet growing expectations. Polyamide (PA) is a material with high potential to replace commonly used low‐performance filament materials, thanks to its cost‐effectiveness and optimal material properties compared to advanced engineering materials. To explore this potential, the thermal, thermomechanical, and mechanical properties (at different temperatures), as well as the wear characteristics, of PA, short carbon fiber reinforced‐PA (SCFR‐PA), and short glass fiber reinforced‐PA (SGFR‐PA) filaments were comparatively examined in this study. Differential scanning calorimeter analysis (DSC), Dynamic Mechanical Thermal Analysis (DMA), uniaxial tensile tests, and Shore D hardness tests were conducted on the 3D printed specimens. The yield strength decreased by 48% and 73%, respectively, for neat PA as compared to room temperature when tested at 40 °C and 60 °C, while for SCFR‐PA, it decreased by 40% and 60%, and for SGFR‐PA, it decreased by 33% and 48%, respectively. The findings obtained from wear tests conducted on both bottom and top surfaces have demonstrated that glass reinforcement yields better results than carbon reinforcement. The experimental findings have been compared with SEM images, revealing their consistency.Highlights This study focuses on the performance evaluation of 3D printed PA and its composites. The mechanical properties of the materials at different temperatures were compared. Adhesive wear behavior is not directly related to fiber type, wear surface or hardness. Morphological analysis was conducted to elucidate the influence of fiber type on mechanical properties and wear behavior.

The Cracking and Tensile-Load-Bearing Behaviour of Concrete Reinforced with Sanded Carbon Grids

This article presents the cracking and load-bearing behaviour of carbon-reinforced prismatic concrete tensile specimens. Grids with different geometries and impregnations were used as carbon reinforcement. In addition, the roving surfaces were partially coated with a fine sand to improve the bond between concrete and reinforcement. The article shows the influence of the different parameters on the developing cracks with respect to their width and spacing from each other. The material properties and tensile strengths of carbon concrete are also presented. These can be used for calculations. A fine-grained, commercially available shotcrete was used for the investigations. Based on the tests and results described in this article, an influence of the sanded carbon grids on the crack properties (crack widths, crack spacing) could be shown in comparison to unsanded carbon grids.

Systematic Mix Design Study on Geopolymers—Prediction of Compressive Strength

Due to the demand for decarbonization of the construction sector, research on alkali-activated binders and material-minimized carbon-reinforced structures has gained momentum in recent years. Most of the research into alkali-activated binders is focused on developing market-ready alternatives, mainly using a trial-and-error approach. In this study, an attempt is made to identify and quantify the factors influencing compressive strength development. Due to their worldwide availability, investigations are being carried out into binders based on calcined clays and natural pozzolans. The goal is to develop a method to produce tailor-made AAB for continuous manufacturing methods to combine carbon reinforcement and alkali-activated materials. For this purpose, an experimental matrix with 20 variation parameters was set up, in which the activator solution and the precursor composition varied. The design of the experiments was used to minimize the number of experiments. It was shown that no single factor is responsible for the development of compressive strength but instead involves several interacting factors. It was possible to find empirical formulas for predicting the compressive strength after 2, 7, and 28 days.

Synergistic Effect of Carbon-Based Reinforcements on the Mechanical Properties of Cement-Based Composites

Carbon reinforcements are used to improve the mechanical properties of cement, allowing the preparation of a strengthened and toughened composite. Functionalization through a reaction with acid is necessary to guarantee both a good dispersion in water and a strong interaction with cement. Different functionalized reinforcements improve the mechanical properties of the composites in comparison with pristine cement. The use of a combination of carbon fibers, carbon nanotubes, and graphene nanoplatelets were analyzed in order to verify their synergistic effect. The use of functionalized carbon nanotubes and carbon fibers demonstrates an improvement of 71% in flexural strength and 540% in fracture energy.

Modular Construction of Topological Interlocking Blocks—An Algebraic Approach for Resource-Efficient Carbon-Reinforced Concrete Structures

An algebraic approach to the design of resource-efficient carbon-reinforced concrete structures is presented. Interdisciplinary research in the fields of mathematics and algebra on the one hand and civil engineering and concrete structures on the other can lead to fruitful interactions and can contribute to the development of resource-efficient and sustainable concrete structures. Textile-reinforced concrete (TRC) using non-crimp fabric carbon reinforcement enables very thin and lightweight constructions and thus requires new construction strategies and new manufacturing methods. Algebraic methods applied to topological interlocking contribute to modular, reusable, and hence resource-efficient TRC structures. A modular approach to construct new interlocking blocks by combining different Platonic and Archimedean solids is presented. In particular, the design of blocks that can be decomposed into various n-prisms is the focus of this paper. It is demonstrated that the resulting blocks are highly versatile and offer numerous possibilities for the creation of interlocking assemblies, and a rigorous proof of the interlocking property is outlined.

Analysis of Thin Carbon Reinforced Concrete Structures through Microtomography and Machine Learning

This study focuses on the development of novel evaluation methods for the analysis of thin carbon reinforced concrete (CRC) structures. CRC allows for the exploration of slender components and innovative construction techniques due to its high tensile strength. In this contribution, the authors have extended the analysis of CRC shells from existing research. The internal structure of CRC specimens was explored using microtomography. The rovings within the samples were segmented from the three-dimensional tomographic reconstructions using a 3D convolutional neural network with enhanced 3D data augmentation strategies and further analyzed using image-based techniques. The main contribution is the evaluation of the manufacturing precision and the simulation of the structural behavior by measuring the carbon grid positions inside the concrete. From the segmentations, surface point clouds were generated and then integrated into a multiscale framework using a parameterized representative volume element that captures the characteristic properties of the textile reinforcement. The procedure is presented using an example covering all necessary design steps from computed tomography to multiscale analysis. The framework is able to effectively evaluate novel construction methods and analyze the linear-elastic behavior of CRC shells.

Embroidered Carbon Reinforcement for Concrete

This research focuses on the manufacturing process and mechanical properties of textile reinforcements fabricated using embroidery technology. The study investigates both 2D and 3D reinforcement products and compares the advantages and possibilities of embroidery technology with other manufacturing methods. A series of tests using carbon reinforcement is conducted, and the results are presented and evaluated comprehensively. The uniaxial tensile tests reveal the characteristic behavior of carbon-reinforced concrete (CRC). Furthermore, the bonding behavior between the concrete matrix and embroidered carbon reinforcement is analyzed utilizing asymmetric pull-out tests, demonstrating that the embroidered reinforcements provide a sufficient bond. In addition to conventional 2D reinforcements, 3D reinforcements were also investigated, which can be efficiently manufactured using the TFP (tailored fiber placement) technology. Through the implementation of stirrup rovings, shear failure loads can be increased significantly. The results suggest that the mechanical properties of the reinforcement are influenced by the manufacturing process, which is particularly evident in the variation between longitudinal and transverse directions. The research highlights the potential benefits of using embroidery technology for textile reinforcement and indicates areas for further research and optimization in the manufacturing process. A pilot project that utilizes the embroidered reinforcement is currently under construction.

Characterization of Hybrid FRP Composite Produced from Recycled PET and CFRP.

In recent years, carbon fiber has experienced a significant surge in popularity attributed to its exceptional properties, including its high-temperature resistance, mechanical strength, and cost-effectiveness. Many industries have been attracted to the prevalent use of carbon-fiber-reinforced polymers or plastics (CFRP). However, the increasing demand for carbon fiber has created a waste recycling problem that needs to be addressed. This research aimed to develop a recycled composite using PET waste as a solution to the growing demand for both materials. The recycled carbon fibers were processed chemically and mechanically to generate power for this process. Various samples were tested with different proportions of CF (10%, 20%, 30%, and 40%) to analyze their mechanical properties. The recycled composites are examined under tensile test conditions to further explore the waste carbon reinforcement's effect on polymers' characteristics. Scanning electron microscopy was also utilized for mechanical morphology evaluations. After analyzing the data, it was found that samples containing 20% CF had the highest elastic modulus value among all the mixes. This is attributed to the reinforcing effect of the fibers. The Elasticity Modulus of the filaments increased with the concentration of CF, reaching its peak at 20% before decreasing. This trend is also apparent in the visual representations. When compared to recycling, the Elasticity Modulus value of 20% CF filament increased by 97.5%. The precise value for CF with a 20% filament is 4719.3 MPa. Moreover, the composite samples were analyzed using SEM to characterize them, and it was discovered that the incorporation of 20% CF/PET filler produced the composition with the highest strength.

The Recycling of Carbon Components and the Reuse of Carbon Fibers for Concrete Reinforcements

Carbon fiber reinforced plastics are increasingly used in all areas of industry. With the increasing number of components and semi-finished products, more and more new carbon fibers will be produced. This also generates a greater number of end-of-life components. These end-of-life components can currently only be fed back, to a limited extent, for reuse, thus leading to a non-optimal, closed-material cycle of the carbon fiber. This article provides an overview of the recycling of carbon components, their further processing and their reuse in reinforcement elements made of carbon fibers. In addition, first results from recycled single fibers and yarn tensile tests from recycled carbon fibers (rCF) are presented. By demonstrating the reuse of carbon fibers in the construction sector, there is the potential to effectively close the carbon cycle. The utilization of carbon reinforcements also enables the reduction of concrete consumption, as the minimum concrete cover required to protect the reinforcement from corrosion is no longer needed.

Microstructure, properties and synergetic effect of graphene oxide-functionalized carbon nanotubes hybrid reinforced copper matrix composites prepared by DC electrodeposition

As the prospective carbon materials, graphene oxide (GO) and carbon nanotubes (CNTs) have attracted extensive attention in the fabrication of copper matrix composites (CMCs), but how their orientation and synergetic effect in Cu matrix affects the properties of composites has not been explored systematically. Herein, an efficient route to fabricate CMCs with GO-CNTs hybrid reinforcement had been reported, as well as the influence of different carbon reinforcement and different current densities on the texture orientation, microstructure and the comprehensive performance were investigated. From ultraviolet–visible results, it was found that one-dimensional CNTs bridge adjacent two-dimensional GO through π-π bonding to form an interconnected network structure. By adding GO-CNTs hybrid reinforcement to pure Cu sulfate, the preferred crystalline orientation of the GO-CNTs/Cu had been changed and a preferred orientation of (111) crystal plane was formed. Meanwhile, the EBSD results revealed that the GO-CNTs hybrid reinforcement had significant grain refinement effect and the average grain size of GO-CNTs/Cu composite reduced to 112 nm. According to TEM images, the lattice stripes between GO and CNTs indicate the formation of C–C covalent bonding. Owing to the synergistic effect and the C–C covalent bonding between GO and CNTs, the highest thermal conductivity reached to 527 W m−1 K−1, while, the highest hardness was up to 226.8 HV0.1, the friction coefficient reduced to 0.62and excellent corrosion resistance of the GO-CNTs/Cu composite were also achieved. This study suggested that the promising fabrication of high-oriented GO-CNTs/Cu composite may have the potential to obtain excellent performance.

Flexible-rigid scalable structures for trans-scale interface reinforcement of carbon fiber/phenolic composites: Effect on properties

Light-weight and high-modulus carbon fiber/phenolic composites, were in large demand of heavy-loading engineering, vehicles and aerospace fields. However, the limitation in the weak interface would cause serious stress concentration and structural failure of materials. Herein, aramid nanofiber (ANF) and cellulose nanofiber (CNF) as flexible units, and zeolitic imidazolate frameworks-8 (ZIF-8) as a rigid unit, were employed to establish a trans-scale reinforced structure on the interphase for balancing the modulus of fibers/resin and improving interfacial properties of the composites. This flexible-rigid (ANF/CNF-ZIF-8) scalable structure, contributed to the integration of various components and forming effective bonds between fibers and the matrix, further promoting mechanical and tribological performances of the composites. Due to the trans-scale interface enhancement of this unique flexible-rigid structure, the flexural strength of 30%ANF-ZIF-8-composite (S1-3) and 30%CNF-ZIF-8-composite (S2-3) improved by 77.68% and 88.46%, respectively. Meanwhile, the elastic modulus of S1-3 and S2-3 reached 5.41 and 5.40 GPa, indicating a significant ascent of 137.28% and 136.84%, respectively. This work provides a promising and effective strategy of constructing a flexible-rigid scalable interfacial structure and opens an avenue toward the large-scale fabrication of new-generation advanced materials.

Measurement and modelling of dynamic fluid saturation in carbon reinforcements

We propose a methodology to monitor the progressive saturation of a non-translucent unidirectional carbon fabric stack through its thickness by means of X-ray radiography and extract the dynamic saturation curves using image analysis. Four constant flow rate injections with increasing flow speed were carried out. These were simulated by a numerical two-phase flow model for both capillary and viscous leading flow conditions. The hydraulic functions describing pressure and relative permeability versus saturation were determined by fitting the saturation curves using a heuristic optimization routine. As the fluid velocity increases and the flow regime at the flow front shifts from capillary to hydrodynamically driven, the resulting capillary pressure curves for a given saturation level are shifted to higher values, from negative to positive. These as well as the capillary pressure calculated from the pressure drop within the unsaturated region of the fabric correlate well with a corresponding change in the averaged dynamic contact angle.

Social Life Cycle Assessment in the Construction Industry: Systematic Literature Review and Identification of Relevant Social Indicators for Carbon Reinforced Concrete

AbstractThis article deals with the application of social life cycle assessment (S-LCA) in the construction sector and explicitly focuses on carbon reinforced concrete (CRC). The publication consists of two parts: (1) a scientific literature review on the current implementation of S-LCA in the construction sector, and (2) the definition of the relevant social hotspots for the cradle-to-gate production of CRC. The literature review was conducted to provide a general overview and compare S-LCA studies in the construction sector; second, countries that provide the relevant input materials needed for CRC were identified. Analysis within the Social Hotspot Database (SHDB) helped determine the relative importance of the CRC supply country for each social category and subcategory. By developing a metric in the form of scores for each risk information, the potential risks indicated by the SHDB were measured. The results show that the focus of the indicators to be highlighted and further used in the indicator catalog is particularly in the area of labor rights and decent work in the health and safety subcategory. Missing data within the SHDB may result in a defined high average score and lead to a lower level of information. In the future, the identified 36 social indicators for CRC should be revised again in cooperation with the manufacturing industry. This study aims to further raise awareness in the construction sector of life-cycle-based sustainability that goes beyond the environmental aspects, and it is the first social hotspot screening using the SHDB for CRC.

Preface

This issue of the Journal of Physics: Conference Series contains the proceedings of the 2022 2nd International Conference on Mechatronics Technology and Aerospace Engineering (ICMTAE 2022). The conference took place in Nanchang, China during November 4th-6th, 2022 (virtual conference), with the attendance of about 100 prominent delegates in related areas all around the world.The conference aims at creating an international academic forum where current research results and technical advances can be exchanged and the development of mechatronics technology and aerospace engineering can be promoted. For this reason, scholars, specialists and researchers in related fields have come together at the conference to present their research activities, share their professional experiences, exchange new ideas, and discuss the key challenges and research directions facing the development of these fields.To make this conference on schedule, we have a three-part plenary conference including a keynote speech part delivered by four speakers from different countries. Among them, Assoc. Prof. Jiuming Xie from Tianjin Sino-German Universities of Applied Sciences-Mechanical Engineering College, China performed a keynote speech on the Preparation and Mechanical Properties of Aluminum Alloy 5A02/CFRTP Laminates. She took the Aluminum Alloy 5A02 /CFRTP (Carbon Fiber Reinforced Thermo-Plastic) laminates as the subject to conduct her research. Aluminum alloy was anodized, compression molding and 3D printing were adopted to prepare Carbon Reinforced Aluminum Laminates (CARALL) with two different structures: the solid core structure and the honeycomb structure, and the prepared specimens were then tested for mechanical properties via tensile test and three-point bending test, and compared with the performance of the conventional aluminum alloy. We are very optimistic that all participants will acquire new ideas and knowledge from this conference to enhance the capability toward mechatronics technology and aerospace engineering.We have received tremendous paper submissions from all over China and abroad. Through a rigorous peer-review process, all submissions were performed double blind review to check their quality of content, level of innovation, significance, originality and legibility. Based on the expertise review comments, some excellent papers were accepted and the corresponding authors were invited to submit their papers for final publication. The accepted papers included topics on: Materials Surface Physics, Combustion and Energy Conversion, Advanced Fluid Mechanics, Satellite and Geophysics, Aerospace Structures, etc.We would like to thank the Conference General Chairs and the Technical Program Committees for their hard work that lead to the organization of this event, to our colleagues who contributed to its realization, to the members of the Journal of Physics: Conference Series for their patience while waiting for the final versions of the papers and to every author who has contributed with an article to these proceedings. We firmly believe that all the attendees have had fruitful discussions and gained valuable knowledge, and will enjoy the opportunity for future collaborations.The Committee of ICMTAE 2022List of Committee member is available in this Pdf.