Search results for: laminated composite materials

Authors: Ziyad Abunada, Abir Al-tabbaa

Abstract:

The current work is investigating the effectiveness of combined mixed materials mainly modified bentonites and organoclay in treating contaminated groundwater. Sodium bentonite was manufactured with a quaternary amine surfactant, dimethyl ammonium chloride to produce organoclay (OC). Inorgano-organo bentonite (IOB) was produced by intercalating alkylbenzyd-methyl-ammonium chloride surfactant into sodium bentonite and pillared with chlorohydrol pillaring agent. The materials efficiency was tested for both TEX compounds from model-contaminated water and a mixture of organic contaminants found in groundwater samples collected from a contaminated site in the United Kingdom. The sorption data was fitted well to both Langmuir and Freundlich adsorption models reflecting the double sorption model where the correlation coefficient was greater than 0.89 for all materials. The mixed materials showed higher sorptive capacity than individual material with a preference order of X> E> T and a maximum sorptive capacity of 21.8 mg/g was reported for IOB-OC materials for o-xylene. The mixed materials showed at least two times higher affinity towards a mixture of organic contaminants in groundwater samples. Other experimental parameters such as pH and contact time were also investigated. The pseudo-second-order rate equation was able to provide the best description of adsorption kinetics.

Keywords: modified bentobite, groundwater, adsorption, contaminats

Procedia PDF Downloads 221

Authors: Shirly May Balais

Abstract:

This study aims to evaluate the effects of vocabulary instruction in improving the students’ learning in science. The teacher-researcher utilized the vocabulary instructional materials in enriching the science vocabulary of grade four learners. The students were also given an achievement test to determine the effects of vocabulary instructional materials. The assessment indicated that students had shown improvement in comprehension and science literacy. This also helps the students to grasp, understand, and communicate appropriate science concepts and the integration of imagery makes learning science fun. In this research, descriptive qualitative methods and observation interviews were used to describe the effects of using vocabulary instructional materials in improving the science vocabulary of grade four learners. The students’ perceptions were studied, analyzed, and interpreted qualitatively.

Keywords: instruction, learning, science, vocabulary

Procedia PDF Downloads 196

Authors: Muhammad Awais Kiani

Abstract:

The field of electronics engineering plays a vital role in the marketing of smart materials. Smart materials are innovative, adaptive materials that can respond to external stimuli, such as temperature, light, or pressure, in order to enhance performance or functionality. As the demand for smart materials continues to grow, it is crucial to understand how electronics engineering can contribute to their marketing strategies. This abstract presents an overview of the role of electronics engineering in the marketing of smart materials. It explores the various ways in which electronics engineering enables the development and integration of smart features within materials, enhancing their marketability. Firstly, electronics engineering facilitates the design and development of sensing and actuating systems for smart materials. These systems enable the detection and response to external stimuli, providing valuable data and feedback to users. By integrating sensors and actuators into materials, their functionality and performance can be significantly enhanced, making them more appealing to potential customers. Secondly, electronics engineering enables the creation of smart materials with wireless communication capabilities. By incorporating wireless technologies such as Bluetooth or Wi-Fi, smart materials can seamlessly interact with other devices, providing real-time data and enabling remote control and monitoring. This connectivity enhances the marketability of smart materials by offering convenience, efficiency, and improved user experience. Furthermore, electronics engineering plays a crucial role in power management for smart materials. Implementing energy-efficient systems and power harvesting techniques ensures that smart materials can operate autonomously for extended periods. This aspect not only increases their market appeal but also reduces the need for constant maintenance or battery replacements, thus enhancing customer satisfaction. Lastly, electronics engineering contributes to the marketing of smart materials through innovative user interfaces and intuitive control mechanisms. By designing user-friendly interfaces and integrating advanced control systems, smart materials become more accessible to a broader range of users. Clear and intuitive controls enhance the user experience and encourage wider adoption of smart materials in various industries. In conclusion, electronics engineering significantly influences the marketing of smart materials by enabling the design of sensing and actuating systems, wireless connectivity, efficient power management, and user-friendly interfaces. The integration of electronics engineering principles enhances the functionality, performance, and marketability of smart materials, making them more adaptable to the growing demand for innovative and connected materials in diverse industries.

Keywords: electronics engineering, smart materials, marketing, power management

Procedia PDF Downloads 57

Authors: Joseph Fitoussi, Mohammadali Shirinbayan, Abbas Tcharkhtchi

Abstract:

Due to material flow during processing, short fiber reinforced composites structures obtained by injection or compression molding generally present strong spatial microstructure variation. On the other hand, quasi-static, dynamic, and fatigue behavior of these materials are highly dependent on microstructure parameters such as fiber orientation distribution. Indeed, because of complex damage mechanisms, SFRC structures design is a key challenge for safety and reliability. In this paper, we propose a micromechanical model allowing prediction of damage behavior of real structures as a function of microstructure spatial distribution. To this aim, a statistical damage criterion including strain rate and fatigue effect at the local scale is introduced into a Mori and Tanaka model. A critical local damage state is identified, allowing fatigue life prediction. Moreover, the multi-scale model is coupled with an experimental intrinsic link between damage under monotonic loading and fatigue life in order to build an abacus giving Tsai-Wu failure criterion parameters as a function of microstructure and targeted fatigue life. On the other hand, the micromechanical damage model gives access to the evolution of the anisotropic stiffness tensor of SFRC submitted to complex thermomechanical loading, including quasi-static, dynamic, and cyclic loading with temperature and amplitude variations. Then, the latter is used to fill out microstructure dependent material cards in finite element analysis for design optimization in the case of complex loading history. The proposed methodology is illustrated in the case of a real automotive component made of sheet molding compound (PSA 3008 tailgate). The obtained results emphasize how the proposed micromechanical methodology opens a new path for the automotive industry to lighten vehicle bodies and thereby save energy and reduce gas emission.

Keywords: short fiber reinforced composite, structural design, damage, micromechanical modelling, fatigue, strain rate effect

Procedia PDF Downloads 107

Authors: Shaher Bano, Samia Fida, Asif Israr

Abstract:

The synergistic effect of properties of metals and fibers reinforced laminates has diverted attention of the world towards use of robust composite materials known as fiber-metal laminates in many high performance applications. In this study, modification of an adhesively bonded joint as a single lap joint of carbon fibers based CARALL FML has done to increase interlaminar shear strength of the joint. The effect of different configurations of joint designs such as spews, stepped and modification in adhesive by addition of nano-fillers was studied. Both experimental and simulation results showed that modified joint design have superior properties as maximum force experienced stepped joint was 1.5 times more than the simple lap joint. Addition of carbon nano-tubes as nano-fillers in the adhesive joint increased the maximum force due to crack deflection mechanism.

Keywords: adhesive joint, Carbon Reinforced Aluminium Laminate (CARALL), fiber metal laminates, spews

Procedia PDF Downloads 235

Authors: Lidan Wang, Shuyuan Zhao, Jianxin He

Abstract:

In this paper, graphene-doped copper indium disulfide (rGO+CuInS2) composite nanofibers were fabricated via electrospinning, in situ synthesis, and carbonization, using polyvinyl pyrrolidone (PVP), copper dichloride (CuCl2), indium trichloride (InCl3), thiourea (C2H5NS) and graphene oxide nanosheets (Go) as the precursor solution for electrospinning. The average diameter of rGO+CuInS2 nanofibers were about 100 nm, and graphene nanosheets anchored with chalcopyrite CuInS2 nanocrystals 8-15 nm in diameter were overlapped and embedded, aligning along the fiber axial direction. The DSSC with a rGO+CuInS2 counter electrode exhibits a power conversion efficiency of 5.93%; better than the corresponding values for a DSSC with a CuInS2 counter electrode, and comparable to that of a reference DSSC with a Pt counter electrode. The excellent photoelectric performance of the rGO+CuInS2 counter electrode was attributed to its high specific surface area, which facilitated permeation of the liquid electrolytes, promoted electron and ion transfer and provided numerous catalytically active sites for the oxidation reaction of the electrolytic (I- /I3-).

Keywords: dye-sensitized solar cells, counter electrode, electrospinning, graphene

Procedia PDF Downloads 456

Authors: M. K. Deore

Abstract:

The thick films of undoped and Al2O3 doped- ZnO were prepared by screen printing technique. AR grade (99.9 % pure) Zinc Oxide powder were mixed mechanochemically in acetone medium with Aluminium Chloride (AlCl2) material in various weight percentages such as 0.5, 1, 3 and 5 wt % to obtain Al2O3 - ZnO composite. The prepared materials were sintered at 1000oC for 12h in air ambience and ball milled to ensure sufficiently fine particle size. The electrical, structural and morphological properties of the films were investigated. The X-ray diffraction analysis of pure and doped ZnO shows the polycrystalline nature. The surface morphology of the films was studied by SEM. The final composition of each film was determined by EDAX analysis. The gas response of undoped and Al2O3- doped ZnO films were studied for different gases such as CO, H2, NH3, and H2S at operating temperature ranging from 50 oC to 450 o C. The pure film shows the response to H2S gas (500ppm) at 300oC while the film doped with 3 wt.% Al2O3 gives the good response to H2S gas(ppb) at 350oC. The selectivity, response and recovery time of the sensor were measured and presented.

Keywords: thick films, ZnO-Al2O3, H2S gas, sensitivity, selectivity, response and recovery time

Procedia PDF Downloads 419

Authors: M. S. Kamarulzaman, N. A. Muhamad, N. A. M. Jamail, M. A. M. Piah, N. F. Kasri

Abstract:

Insulation for high voltage application that has been service for a very long time is subjected to several types of degradation. The degradation can lead to premature breakdown and definitely will spent highly cost to replace the cable. Thus, there are many research on nano composite material get serious attention attention due to their abilities to enhance electrical performance by addition of nano filler. In this paper, water absorption of Low Linear Density Polyethyelene (LLDPE) with different amount of nano filler added is studied. This study is necessary to be conducted since most of electrical apparatus such as cable insulation are dominant used especially in high voltage application. The cable insulation are continuously exposed in uncontrolled environment may suffer degradation process. Three type of nano fillers, was used in this study are: Silicon dioxide (SiO2), Titanium dioxide (TiO2) and Monmorillonite (MMT). The percentage absorption of water was measured by weighted using high precision scales for absorption process up to 92 days. Experimental result demonstrate that SiO2 absorb less water than other filler while, the MMT has hydrophilic properties which it absorbs more water compare to another sample.

Keywords: nano composite, nano filler, water absorption, hydrophilic properties

Procedia PDF Downloads 355

Authors: Balwinder Singh

Abstract:

The present research is a paper on the characterization of aluminum alloy-6063 hybrid metal matrix composites using three different reinforcement materials (SiC, red mud, and fly ash) through stir casting method. The red mud was used in solid form, and particle size range varies between 103-150 µm. During this investigation, fly ash is received from Guru Nanak Dev Thermal Plant (GNDTP), Bathinda. The study has been done by using Taguchi’s L9 orthogonal array by taking fraction wt.% (SiC 5%, 7.5%, and 10% and Red Mud and Fly Ash 2%, 4%, and 6%) as input parameters with their respective levels. The study of the mechanical properties (tensile strength, impact strength, and microhardness) has been done by using Analysis of Variance (ANOVA) with the help of MINITAB 17 software. It is revealed that silicon carbide is the most significant parameter followed by red mud and fly ash affecting the mechanical properties, respectively. The fractured surface morphology of the composites using Field Emission Scanning Electron Microscope (FESEM) shows that there is a good mixing of reinforcement particles in the matrix. Energy-dispersive X-ray spectroscopy (EDS) was performed to know the presence of the phases of the reinforced material.

Keywords: reinforcement, silicon carbide, fly ash, red mud

Procedia PDF Downloads 158

Authors: Benny Alexander, Ikhlashia N. Fadhilah, Muhammad R. Pasha, Michelle Julia, Anne Z. Syahrial

Abstract:

Brake shoe is a component that serves to reduce speed or stop the train's speed by utilizing the friction force. Generally, the material used as a brake shoe is cast iron, where cast iron itself is a heavy, expensive, and easily worn material. Aluminum matrix composites are one of candidates for the cast iron replacement material as the basic material for brake shoe. The matrix in the composite used is Aluminum AC4B. Reinforcement used in aluminum matrix composites is nano-alumina, where the use of nano-alumina of 0.25%, 0.3%, 0.35%, 0.4%, and 0.5% volume fraction will be tested. The sample is made using the stir casting method; then, it will be tested mechanically. The use of nano-alumina as a reinforcement will increase the strength of the matrix. SEM (scanning electron microscopy) testing is used to test the distribution of reinforcing particles due to stirring. Therefore, the addition of nano-alumina will improve AC4B aluminum matrix composites.

Keywords: aluminium matrix composites, brake shoe application, stir casting, nano-alumina

Procedia PDF Downloads 131

Authors: Shanawaz Patil, Mohamed Haneef, K. S. Narayanaswamy

Abstract:

In the recent years, aluminum metal matrix composites were most widely used, which are finding wide applications in various field such as automobile, aerospace defense etc., due to their outstanding mechanical properties like low density, light weight, exceptional high levels of strength, stiffness, wear resistance, high temperature resistance, low coefficient of thermal expansion and good formability. In the present work, an effort is made to study the effect of heat treatment on mechanical properties of aluminum 7075 alloy reinforced with constant weight percentage of naturally occurring mineral beryl and varying weight percentage of graphene. The hybrid composites are developed with 0.5 wt. %, 1wt.%, 1.5 wt.% and 2 wt.% of graphene and 6 wt.% of beryl  by stir casting liquid metallurgy route. The cast specimens of unreinforced aluminum alloy and hybrid composite samples were prepared for heat treatment process and subjected to solutionizing treatment (T6) at a temperature of 490±5 ^oC for 8 hours in a muffle furnace followed by quenching in boiling water. The microstructure analysis of as cast and heat treated hybrid composite specimens are examined by scanning electron microscope (SEM). The tensile test and hardness test of unreinforced aluminum alloy and hybrid composites are examined. The wear behavior is examined by pin-on disc apparatus. The results of as cast specimens and heat treated specimens were compared. The heat treated Al7075-Beryl-Graphene hybrid composite had better properties and significantly improved the ultimate tensile strength, hardness and reduced wear loss when compared to aluminum alloy and  as cast hybrid composites.

Keywords: beryl, graphene, heat treatment, mechanical properties

Procedia PDF Downloads 143

Authors: Ljerka Kratofil Krehula, Vanja Gilja, Andrea Husak, Sniježana Šuka, Zlata Hrnjak-Murgić

Abstract:

Zinc oxide (ZnO) can be used as photocatalysts for water purification. However, one particular interest is given on the integration of inorganic ZnO nanoclusters with conducting polymers because the resulting nanocomposites may possess unique properties and enhanced photocatalytic activity in comparison to pure ZnO, using UV and also visible light. It is needed to explore the appropriate structure of polypyrrole that can induce activation of ZnO photocatalyst since the synthesis of organic/inorganic hybrid materials can result in a synergistic and complementary feature, increasing ZnO photocatalytic efficiency. In this paper several different composites of polypyrrole/zinc oxide (ZnO) were studied. Composite samples were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV) and scanning electron microscopy (SEM). The photocatalytic efficiency of prepared samples was studied as a decomposition of Reactive Red 45 (RR 45) dye, which was monitored by UV-Vis spectroscopy as a change in absorbance of characteristic wavelength at 542 nm. Results show good photocatalytic efficiency of all nanocomposite samples.

Keywords: photocatalysis, polypyrrole, wastewater, zinc oxide

Procedia PDF Downloads 264

Authors: Heeyoung Lee, Woosung Bin, Kangseog Seo, Hyojeong Yun, Zuog An

Abstract:

Recently, a new continuous bridge system has been proposed to increase the space under the bridge and to improve aesthetic aspect of the urban area. The main feature of the proposed bridge is to connect steel I-girders and coping by means of prestressed high-strength steel bars and steel plate. The proposed bridge is able to lower the height of the bridge to ensure the workability and efficiency through a reduction of the cost of road construction. This study presents the experimental result of the full-scale connection between steel I-girders and coping under the negative bending moment. The composite behavior is thoroughly examined and discussed under the specific load levels such as service load, factored load and crack load. Structural response showed full composite action until the final load level because no relative displacement between coping and girder was observed. It was also found prestressing force into high-strength bars was able to control tensile stresses of deck slab. This indicated that cracks in deck slab can be controlled by above-mentioned prestressing force.

Keywords: coping, crack, integrated bridge, full-scale test

Procedia PDF Downloads 439

Authors: G. Voicu, C. D. Ghitulica, A. Cucuruz, C. Busuioc

Abstract:

In the field of tissue engineering, the compositional and microstructural features of the employed materials play an important role, with implications on the mechanical and biological behaviour of the medical devices. In this context, the development of calcium phosphate-natural biopolymer composites represents a choice of many scientific groups. Thus, tricalcium phosphate powders were synthesized by a wet method, namely co-precipitation, starting from high purity reagents. Moreover, the substitution of calcium with magnesium have been approached, in the 5-10 wt.% range. Afterwards, the phosphate powders were integrated into two types of composites with chitosan, different from morphological point of view. First, 3D porous scaffolds were obtained by a freeze-drying procedure. Second, uniform compact films were achieved by film casting. The influence of chitosan molecular weight (low, medium and high), as well as phosphate powder to polymer ratio (1:1 and 1:2) on the morphological properties, were analysed in detail. In conclusion, the reported biocomposites, prepared by a straightforward route are suitable for bone substitution or repairing applications.

Keywords: bone reconstruction, chitosan, composite scaffolds, tricalcium phosphate

Procedia PDF Downloads 243

Authors: W. F. Ribeiro, J. L. N. Góes

Abstract:

The industrial process adds to engineering wood products features absent in solid wood, with homogeneous structure and reduced defects, improved physical and mechanical properties, bio-deterioration, resistance and better dimensional stability, improving quality and increasing the reliability of structures wood. These features combined with using fast-growing trees, make them environmentally ecological products, ensuring a strong consumer market. The wood I-joists are manufactured by the industrial profiles bonding flange and web, an important aspect of the production of wooden I-beams is the adhesive joint that bonds the web to the flange. Adhesives can effectively transfer and distribute stresses, thereby increasing the strength and stiffness of the composite. The objective of this study is to evaluate different resins in a shear strain specimens with the aim of analyzing the most efficient resin and possibility of using national products, reducing the manufacturing cost. First was conducted a literature review, where established the geometry and materials generally used, then established and analyzed 8 national resins and produced six specimens for each.

Keywords: engineered wood products, structural resin, wood i-joist, Pinus taeda

Procedia PDF Downloads 276

Authors: Anthony Chidi Ezika, Gbolahan Joseph Adekoya, Emmanuel Rotimi Sadiku, Yskandar Hamam, Suprakas Sinha Ray

Abstract:

High-energy-density polymer/ceramic composites require a high breakdown strength and dielectric constant. Interface polarization and electric percolation are responsible for the high dielectric constant. In order to create composite dielectrics, high conductivity ceramic particles are combined with polymers to increase the dielectric constant. In this study, bonding and the non-uniform distribution of charges in the ceramic/ceramic interface zone are investigated using density functional theory (DFT) modeling. This non-uniform distribution of charges is intended to improve the ceramic/ceramic interface's dipole polarization (dielectric response). The interfacial chemical bond formation can also improve the structural stability of the hybrid filler and, consequently, of the composite films. To comprehend the electron-transfer process, the density of state and electron localization function of the PPy with hybrid fillers are also studied. The polymer nanocomposite is anticipated to provide a suitable dielectric response for energy storage applications.

Keywords: energy storage, V₂C/ ZnS hybrid, polypyrrole, MXene, nanocomposite, dielectric

Procedia PDF Downloads 115

Authors: Min Ye Koo, Gyo Woo Lee

Abstract:

In this study, epoxy composite specimens reinforced with multi-walled carbon nanotube filler were fabricated using shear mixer and ultra-sonication processor. The mechanical and thermal properties of the fabricated specimens were measured and evaluated. From the electron microscope images and the results from the measurements of tensile strengths, the specimens having 0.6 wt% nanotube content show better dispersion and higher strength than those of the other specimens. The Young’s moduli of the specimens increased as the contents of the nanotube filler in the matrix were increased. The specimen having a 0.6 wt% nanotube filler content showed higher thermal conductivity than that of the other specimens. While, in the measurement of thermal expansion, specimens having 0.4 and 0.6 wt% filler contents showed a lower value of thermal expansion than that of the other specimens. On the basis of the measured and evaluated properties of the composites, we believe that the simple and time-saving fabrication process used in this study was sufficient to obtain improved properties of the specimens.

Keywords: carbon nanotube filler, epoxy composite, ultra-sonication, shear mixer, mechanical property, thermal property

Procedia PDF Downloads 369

Authors: Fuad Ameen, Mohamed Moslem, Sarfaraz Hadi

Abstract:

Twenty-eight fungal isolates belonging to 12 genera were derived from debris, sediment and water samples collected from Avicennia marina stands 25km south of Jeddah city on the Red Sea coast of Saudi Arabia. Eight of these isolates were found to be able to grow in association cellulosic waste materials under in vitro conditions in the absence of any carbon source. Isolates were further tested for their potential to degrade paper and clothes wastes by co-cultivation under aeration on a rotary shaker. These fungi accumulated significantly higher biomass, produced ligninolytic and cellulase enzymes, and liberated larger volumes of CO2. These observations indicated that the selected isolates were able to break down and consume the waste materials.

Keywords: biodegradation, enzyme activity, waste materials, mangrove

Procedia PDF Downloads 564

Authors: Abhijeet Kumar, Palaniswamy N. K.

Abstract:

Heavy metal contamination in water sources endangers both the environment and human health. Various water filtration techniques have been employed till now for purification and removal of hazardous metals from water. Among all the existing methods, nanofibres have emerged as a viable alternative for effective heavy metal removal in recent years because of their unique qualities, such as large surface area, interconnected porous structure, and customizable surface chemistry. Among the numerous manufacturing techniques, solution blow spinning has gained popularity as a versatile process for producing nanofibers with customized properties. This paper seeks to offer a complete overview of the use of nanofibers for heavy metal filtration, particularly those produced using solution blow spinning. The review discusses current advances in nanofiber materials, production processes, and heavy metal removal performance. Furthermore, the field's difficulties and future opportunities are examined in order to direct future research and development activities.

Keywords: heavy metals, nanofiber composite, filter membranes, adsorption, impaction

Procedia PDF Downloads 66

Authors: Maryam Shirmohammadi, Prasad K. D. V. Yarlagadda, YuanTong Gu

Abstract:

The mechanical damage on the agricultural crop during and after harvesting can create high volume of damage on tissue. Uniaxial compression and tensile loading were performed on flesh and peel samples of pumpkin. To investigate the structural changes on the tissue, Scanning Electron Microscopy (SEM) was used to capture the cellular structure change before and after loading on tissue for tensile, compression and indentation tests. To obtain required mechanical properties of tissue for the finite element analysis (FEA) model, laser measurement sensors were used to record the lateral displacement of tissue under the compression loading. Uniaxial force versus deformation data were recorded using Universal Testing Machine for both tensile and compression tests. The experimental Results were employed to develop a material model with failure criteria. The results obtained by the simulation were compared with those obtained by experiments. Note that although modelling food materials’ behaviour is not a new concept however, majority of previous studies focused on elastic behaviour and damages under linear limit, this study, however, has developed FEA models for tensile and compressive loading of pumpkin flesh and peel samples using, as the first study, both elastic and elasto-plastic material types. In addition, pumpkin peel and flesh tissues were considered as two different materials with different properties under mechanical loadings. The tensile and compression loadings were used to develop the material model for a composite structure for FEA model of mechanical peeling of pumpkin as a tough skinned vegetable.

Keywords: compressive and tensile response, finite element analysis, poisson’s ratio, elastic modulus, elastic and plastic response, rupture and bio-yielding

Procedia PDF Downloads 330

Authors: Janmejoy Gupta, Arnab Paul, Manjari Chakraborty

Abstract:

Jharkhand is a state located in the eastern part of India. The Tropic of Cancer (23.5 degree North latitude line) passes through Ranchi district in Jharkhand. Mud huts with burnt clay tiled roofs in Jharkhand are an integral component of the state’s vernacular architecture. They come in various shapes, with a number of them having a courtyard type of plan. In general, it has been stated that designing dwellings with courtyards in them is a climate-responsive strategy in composite climate. The truth behind this hypothesis is investigated in this paper. In this paper, three types of mud huts with courtyards situated in Ranchi district in Jharkhand are taken as a study and through temperature measurements in the south-side rooms and courtyards, in addition to Autodesk Ecotect (Version 2011) software simulations, their thermal performance throughout the year are observed. Temperature measurements are specifically taken during the peak of summer and winter and the average temperatures in the rooms and courtyards during seven day-periods in peak of summer and peak of winter are plotted graphically. Thereafter, on the basis of the study and software simulations, the hypothesis is verified and the thermally better performing dwelling types in summer and winter identified among the three sub-types studied. Certain recommendations with respect to increasing thermal comfort in courtyard type mud huts in general are also made. It is found that all courtyard type dwellings do not necessarily show better thermal performance in summer and winter in composite climate. The U shaped dwelling with open courtyard on southern side offers maximum amount of thermal-comfort inside the rooms in the hotter part of the year and the square hut with a central courtyard, with the courtyard being closed from all sides, shows superior thermal performance in winter. The courtyards in all the three case-studies are found to get excessively heated up during summer.

Keywords: courtyard, mud huts, simulations, temperature measurements, thermal performance

Procedia PDF Downloads 405

Authors: Mohamed T. El-Hawary, Carsten Koenke, Amr M. El-Nemr, Nagy F. Hanna

Abstract:

Sustainable construction materials using solid construction wastes are of great environmental and economic significance. Construction wastes, demolishing wastes, and wastes coming out from the preparation of traditional materials could be used in sustainable concrete manufacture, which is the main scope of this paper. Ceramics, clay bricks, marble, recycled concrete, and many other materials should be tested and validated for use in the manufacture of green concrete. Introducing waste materials in concrete helps in reducing the required landfills, leaving more space for land investments, and decrease the environmental impact of the concrete buildings industry in both stages -construction and demolition-. In this paper, marble aggregate is used as a replacement for the natural aggregate in sustainable green concrete production. The results showed that marble aggregates can be used as a full replacement for the natural aggregates in eco-friendly green concrete.

Keywords: coarse aggregate replacement, economical designs, green concrete, marble aggregates, sustainability, waste management

Procedia PDF Downloads 146

Authors: Vara Prasad Vemu

Abstract:

The aim of the present work is to investigate the mechanical properties and water absorption capacity of carbon and basalt fibers mixed with matrix epoxy. At present, there is demand for nature friendly products. Basalt reinforced composites developed recently, and these mineral amorphous fibres are a valid alternative to carbon fibres for their lower cost and to glass fibres for their strength. The present paper describes briefly on basalt and carbon fibres (uni-directional) which are used as reinforcement materials for composites. The matrix epoxy (LY 556-HY 951) is taken into account to assess its influence on the evaluated parameters. In order to use reinforced composites for structural applications, it is necessary to perform a mechanical characterization. With this aim experiments like tensile strength, flexural strength, hardness and water absorption are performed. Later the mechanical properties obtained from experiments are compared with ANSYS software results.

Keywords: carbon fibre, basalt fibre, uni-directional, reinforcement, mechanical tests, water absorption test, ANSYS

Procedia PDF Downloads 196

Authors: Sehijpal Singh Khangura, Jai Inder Preet Singh, Vikas Dhawan

Abstract:

Global warming, growing awareness of the environment, waste management issues, dwindling fossil resources, and rising oil prices resulted to increase the research in the materials that are friendly to our health and environment. Due to these reasons, green products are increasingly being promoted for sustainable development. In this work, fully biodegradable green composites have been developed using jute fibers as reinforcement and poly lactic acid as matrix material by film stacking technique. The effect of curing temperature during development of composites ranging from 160 °C, 170 °C, 180 °C and 190 °C was investigated for various mechanical properties. Results obtained from various tests indicate that impact strength decreases with an increase in curing temperature, but tensile and flexural strength increases till 180 °C, thereafter both the properties decrease. This study gives an optimum curing temperature for the development of jute/PLA composites.

Keywords: natural fibers, polymer matrix composites, jute, compression molding, biodegradation

Procedia PDF Downloads 144

Authors: Amit Kumar Haldar, Mark Simms, Ian McDevitt, Anthony Comer

Abstract:

Interface properties of fiber metal laminates (FML) affects the integrity and deformation failure modes. In this paper, the mechanical behaviours of Ti/GFRP/Ti laminates were experimentally investigated through low-velocity impact tests. Two different surface treatments of Titanium (Ti-6Al-4V) alloy sheets were prepared to obtain the composite interface properties based on annealing and sandblast surface treatment processes. The deformation failure modes, impact load sustaining ability and energy absorption capacity of FMLs were analysed. The impact load and modulus were shown to be dependent on the surface treatments of Titanium (Ti-6Al-4V) alloy sheets. It was demonstrated that the impact load performance was enhanced when titanium surfaces were annealed and sandblasted. It has also been shown that the values of the strength and energy absorption were slightly higher when the tests conducted at relatively higher loading rate, as a result of the rate-sensitive effects on the damage resistance of the FML.

Keywords: fiber metal laminates, metal composite interface, indentation, low velocity impact

Procedia PDF Downloads 195

Authors: Mohammad Momeenul Islam, U. Johnson Alengaram, Mohd Zamin Jumaat, Iftekhair Ibnul Bashar

Abstract:

Palm oil industry produces millions of tonnes of industrial wastes and these wastes create huge storage and environmental problems. In order to solve these problems various research works have been performed for past decades. The commonly available wastes are Oil palm shells (OPS) and Palm oil fuel ash (POFA). These materials have already acquired well recognition as alternate of conventional construction materials. OPS has been used as coarse aggregate and compressive strength was found up to 56 MPa for 56-day. It is said that 30 grade Oil Palm shell concrete (OPSC) is possible without adding any cementitious materials. The maximum modulus of elasticity for OPSC was found 18.6 GPa. The Oil palm shell concrete (OPSC) are used in country areas and nearby areas where the palm oil factories are located for houses, road-kerbs, drain blocks, etc. In case of superstructure like beams and slab are also produced by utilizing OPS. Many experimental works have been performed to establish POFA as a substituting binding material in replace of Ordinary Portland cement (OPC). Throughout the research it has been showed that up to 20% of cement by mass can be replaced by POFA. POFA is one of the most enriched pozzolanic materials. The main purpose of this review is to discuss the usage and opportunity of the palm oil industrial wastes as construction materials following the previous experimental research work.

Keywords: construction materials, oil palm shells (OPS), palm oil fuel ash (POFA), aggregates

Procedia PDF Downloads 353

Authors: Steven Ploetz, Andreas Lohmueller, Robert F. Singer

Abstract:

The outstanding performance of aluminum matrix composites (AMCs) regarding stiffness/weight ratio makes AMCs attractive material for lightweight construction. Low-density boride compounds promise simultaneously an increase in stiffness and decrease in composite density. This is why boron carbide is chosen for composite manufacturing. The composites are fabricated with the stir casting process. To avoid gas entrapment during mixing and ensure nonporous composites, partial vacuum is adapted during particle feeding and stirring. Poor wettability of boron carbide with liquid aluminum hinders particle incorporation, but alloying elements such as magnesium and titanium could improve wettability and thus particle incorporation. Next to alloying elements, adapted stirring parameters and impeller geometries improve particle incorporation and enable homogenous particle distribution and high particle volume fractions of boron carbide. AMCs with up to 15 vol.% of boron carbide particles are produced via melt stirring, resulting in an increase in stiffness and strength.

Keywords: aluminum matrix composites, boron carbide, stiffness, stir casting

Procedia PDF Downloads 307

Authors: V. Samulionis, J. Banys, A. Sánchez-Ferrer

Abstract:

Inorganic nanoparticles are used for fabrication of various composites based on polymer materials because they exhibit a good homogeneity and solubility of the composite material. Multifunctional materials based on composites of a polymer containing inorganic nanotubes are expected to have a great impact on industrial applications in the future. An emerging family of such composites are polyurea elastomers with inorganic MoS2 nanotubes or MoSI nanowires. Polyurea elastomers are a new kind of materials with higher performance than polyurethanes. The improvement of mechanical, chemical and thermal properties is due to the presence of hydrogen bonds between the urea motives which can be erased at high temperature softening the elastomeric network. Such materials are the combination of amorphous polymers above glass transition and crosslinkers which keep the chains into a single macromolecule. Polyurea exhibits a phase separated structure with rigid urea domains (hard domains) embedded in a matrix of flexible polymer chains (soft domains). The elastic properties of polyurea can be tuned over a broad range by varying the molecular weight of the components, the relative amount of hard and soft domains, and concentration of nanoparticles. Ultrasonic methods as non-destructive techniques can be used for elastomer composites characterization. In this manner, we have studied the temperature dependencies of the longitudinal ultrasonic velocity and ultrasonic attenuation of these new polyurea elastomers and composites with inorganic nanoparticles. It was shown that in these polyurea elastomers large ultrasonic attenuation peak and corresponding velocity dispersion exists at 10 MHz frequency below room temperature and this behaviour is related to glass transition Tg of the soft segments in the polymer matrix. The relaxation parameters and Tg depend on the segmental molecular weight of the polymer chains between crosslinking points, the nature of the crosslinkers in the network and content of MoS2 nanotubes or MoSI nanowires. The increase of ultrasonic velocity in composites modified by nanoparticles has been observed, showing the reinforcement of the elastomer. In semicrystalline polyurea elastomer matrices, above glass transition, the first order phase transition from quasi-crystalline to the amorphous state has been observed. In this case, the sharp ultrasonic velocity and attenuation anomalies were observed near the transition temperature TC. Ultrasonic attenuation maximum related to glass transition was reduced in quasicrystalline polyureas indicating less influence of soft domains below TC. The first order phase transition in semicrystalline polyurea elastomer samples has large temperature hysteresis (> 10 K). The impact of inorganic MoS2 nanotubes resulted in the decrease of the first order phase transition temperature in semicrystalline composites.

Keywords: inorganic nanotubes, polyurea elastomer composites, ultrasonic velocity, ultrasonic attenuation

Procedia PDF Downloads 298

Authors: Ahmad Odeh

Abstract:

Researchers are currently more concerned about the calculations of energy at the operational stage, mainly due to its larger environmental impact, but the fact remains, embodied energies represent a substantial contributor unaccounted for in the overall energy computation method. The calculation of materials’ embodied energy during the construction stage is complicated. This is due to the various factors involved. The equipment used, fuel needed, and electricity required for each type of materials varies with location and thus the embodied energy will differ for each project. Moreover, the method used in manufacturing, transporting and putting in place will have significant influence on the materials’ embodied energy. This anomaly has made it difficult to calculate or even bench mark the usage of such energies. This paper presents a model aimed at calculating embodied energies based on such variabilities. It presents a systematic approach that uses an efficient method of calculation to provide a new insight for the selection of construction materials. The model is developed in a BIM environment. The quantification of materials’ energy is determined over the three main stages of their lifecycle: manufacturing, transporting and placing. The model uses three major databases each of which contains set of the construction materials that are most commonly used in building projects. The first dataset holds information about the energy required to manufacture any type of materials, the second includes information about the energy required for transporting the materials while the third stores information about the energy required by machinery to place the materials in their intended locations. Through geospatial data analysis, the model automatically calculates the distances between the suppliers and construction sites and then uses dataset information for energy computations. The computational sum of all the energies is automatically calculated and then the model provides designers with a list of usable equipment along with the associated embodied energies.

Keywords: BIM, lifecycle energy assessment, building automation, energy conservation

Procedia PDF Downloads 188

Authors: Rajai Al-Rousan

Abstract:

The repair and strengthening of concrete structures is a big challenge for the concrete industry for both engineers and contractors. Due to increasing economical constraints, the current trend is to repair/upgrade deteriorated and functionally obsolete structures rather than replacing them with new structures. CFRP has been used previously by air space industries regardless of the high costs. The decrease in the costs of the composite materials, as results of the technology improvement, has made CFRP an alternative to conventional materials for many applications. The primary objective of this research is to investigate the flexural behavior of reinforced concrete (RC) beams externally strengthened with CFRP composites exposed for three years for the following conditions: (a) room temperature, (b) cyclic ponding in 15% salt-water solution, (c) hot-water of 65oC, and (d) rapid freeze/thaw cycles. Results indicated that the after three years of various environmental conditions, the bond strength between the concrete beams and CFRP sheets was not affected. No signs of separation or debonding of CFRP sheets were observed before testing. Also, externally strengthening RC beams with CFRP sheets leads to a substantial increase in the ductility of concrete structures. This is a result of forcing the concrete to undergo inelastic deformation, resulting in compression failure of the structure after yielding of steel reinforcement. In addition, exposure to heat water tank for three years reduces the ultimate load by about 11%. This 11% reduction in the ultimate load equates to about 53%, 46% and 68% loss of the gain of the strength attributed to the CFRP of 2/3 Layer, 1 Layers and 2 Layers CFRP Sheets respectively. This mean that with decreasing of number of layers the environmental exposure had an efficient effect on concrete by protection concrete from environmental effect and adverse effect on the bond performance.

Keywords: flexural, behavior, CFRP, composites, environment, conditions

Procedia PDF Downloads 308