Browsing by Author "Sivahar, V"

Now showing 1 - 20 of 101

item: Conference-Abstract
Activated graphene oxide for removal of methylene blue from wastewater
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Raveena, LAL; Viraji, HA; Rathnayake, RMSL; Sitinamaluwa, HS; Sivahar, V
Lately, activated oxidized graphene has sparked a lot of attention in the fields of wastewater treatment and water filtration. Here, the possibility for using activated graphene oxide (AGO) to remove methylene blue (MB) from water systems was investigated. Commercially available Graphene Oxide (GO) was obtained, and it was further modified by alkali-activation method to obtain AGO. The resulting AGO was tested as an adsorbent for methylene blue removal. Activation time was varied to optimize the MB removal of the adsorbent and then the adsorbents were characterized by using FTIR, SEM, BET and XRD analysis. Synthesized AGO shows prominent MB adsorption characteristics due to H-bonding, and electrostatic interactions. To evaluate the adsorption capacity, batch adsorption experiments were carried out and the effect of pH and temperature on dye adsorption were investigated. Maximum adsorption capacity of 123.47 mg/g was obtained for AGO sample which was activated for 1.0h and the data were well fitted to Langmuir isotherm model. These findings demonstrate the possibility for cationic dye removal from wastewater systems using an economically viable AGO.
item: Thesis-Full-text
Analysis of corrosion of aircraft fluid pressure lines using eddy current
Edirisinghe, DR; Sivahar, V
The metal tubes are often used in aircraft to convey fluids to one or more destinations as they are capable of withstanding high levels of internal pressure and hoop stresses. The internal surfaces of fluid carrying metal tubes are frequently corroded once the inner walls are contacted with stagnated fluid for a long period of time. Once corroded, the fluid lines are to be replaced as they become unairworthy. The detection is difficult as there is no method developed for the corrosion detection of small diameter Aluminium metal tubes. This study is to carry out eddy current inspections on small diameter metal tubes and to carry out a qualitative analyze on eddy current impedance plane displays, building up a relationship on the resultant signals. It is also to distinguish the different characteristics of impedance plane displays of internal corrosion and crack signals. A qualitative analysis is the objective in this study as detection of corrosion is the prime objective for the aircraft fluid pressure lines. Since, neither the aircraft manufacturer nor pressure lines manufacturer has given any tolerances for corrosion, irrespective of the depth and the spread of corrosion, the fluid lines are to be replaced with new lines, if the corrosion is detected. Therefore, this study is limited only for a qualitative analysis and will be an eye opener for another study for a quantitative analysis.
item: Conference-Abstract
Characterization of creep behaviour of viscoelastic materials by ultrasound pulse- echo technique
(Department of Materials Science and Engineering, University of Moratuwa., 2022-11) HEWESSAGE, HDDN; KOTHALAWALA, SSW; Sivahar, V; Abeygunawardana, AAGA
For any viscoelastic material, creep is a phenomenon which tends to change microstructure and the mechanical properties of material. Therefore, it is important to quantify and predict the creep and creep rate of a component. In this investigation, several samples of LDPE were used to measure the creep and both ultrasonic attenuation and velocity measurements using a 5 MHz transducer were employed for characterizing the samples. Our findings indicate that velocity and attenuation measurements can be used to characterize and quantify creep and creep rate of viscoelastic materials.
item: Thesis-Abstract
Correlation between corrosion rate and ultrasonic attenuation on steel
Dayananda, HGSM; Sivahar, V; Munasinghe, RGNDS
Corrosion is the gradual destruction of material, usually metal, by chemical reaction with its environment. Usually the corrosion rate cannot be measured directly which needs sample preparation, fixing of samples in a particular environment, measuring the weight loss during a given period of time and measuring other parameters (time of wetness, SO2 & NO2 concentration, etc.). This research work was based on measuring the corrosion rate using ultrasound technique, which can be named as a nondestructive testing method. Ultrasound defined as the sound waves, which has a frequency more than 20 kHz. To investigate the behavior of corrosion in accelerated atmospheric conditions mild steel samples was exposed to the concentrated NaCl solution. The assessment mainly conducted by evaluating the loss of mass of specimens against the ultrasonic attenuation. Weight loss is the parameter of corrosion rate and it has a relationship with the surface roughness of the samples. The surface roughness of the samples have an influence on the ultrasonic attenuation. Therefore, corrosion rate has a relationship between ultrasonic attenuation. In this project, efforts were made to find a correlation between surface roughness and ultrasonic attenuation. An equation was derived to calculate the corrosion rate if the ultrasonic attenuation is measured. This method has the advantage of assessing the corrosion rate without sample preparation on a given component.
item: Conference-Abstract
Correlation between ultrasonic attenuation and hardness of tool steels
(2008) Dayananda, HGSM; Munasinghe, RGNDS; Sivahar, V
Theory of propagation and reflection of ultrasonic waves in metals in used to locate the internal defects of engineering components. It is observed that the energy absorption of ultrasonic waves (attenuation) in a metal depends on the physical and mechanical properties of metals. In this work efforts are made to find the correlation between attenuation and hardness of metals using ultrasonic waves. Commercially available Ultrasonic Flaw Detector bas been used to measure the attenuation of the ultrasonic waves of tool steel (DF2) which has been beat treated to change its hardness. The experimental curve is compared with theoretical equation and it was observed that the experimental values confirm the theoretically proven co-relationship.
item: Conference-Abstract
Design and simulation of solid state micropump based on piezoelectric actuator
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Sivahar, V
This research presents the design and simulation of a solid-state insulin micropump based on a piezoelectric actuator for a wearable insulin pump device to be used on the human body. The primary objectives of this design are to minimize the need for frequent dosing, replace oral therapy, and alleviate the discomfort associated with painful injections for individuals with diabetes. Our research provides an overview of key concepts, the operating principle, and the design considerations of the micropump. The selection of materials, theoretical studies, and the optimization process of the pump were also investigated in our research. Finite element analysis was employed to optimize the design, and the simulations were conducted using COMSOL Multiphysics 5.3a software in the research. By utilizing the piezoelectric actuator, the proposed micropump demonstrates promising potential for reasonable insulin delivery. The simulations enable the evaluation of various parameters such as actuator performance, fluid flow dynamics, and overall flowrate. The results obtained from the simulations provided valuable insights into the overall performance of the pump and aid in its refinement. The integration of wearable insulin pump devices with this micropump design opens new possibilities for convenient and effective diabetes management.
item: Conference-Abstract
Design of a Dynamic Mechanical Analyser for Rubber Compounds
(Society of Materials Engineering Students, Department of Materials Science and Engineering, University of Moratuwa, 2017-03) Herath, HMRC; Rodrigo, IJ; Weragoda, VSC; Sivahar, V
Dynamic mechanical analysis (DMA) is a powerful technique for characterization of the viscoelastic properties of polymers such as thermoplastics, composites, thermosets and elastomers in the form of sheet specimens, films, fibers, coatings or adhesives. DMA instruments measure the modulus (stiffness) and damping (energy dissipation) properties of materials as they are deformed under dynamic stress. When a polymeric material is subjected to a cyclic sinusoidal stress within the viscoelastic region, the corresponding strain in the material would be out of phase due to the delayed response of the viscous portion of the material. This phase difference corresponds to the frequency of the force application and this is a unique characteristic of the polymer material. Amplitude of the strain curve and phase shift between stress and strain curves are usually identified as basic parameters. In this design which is based on the ISO 6725 standard, forced vibration method was used and the vibrations are impacted by the inertia force of an eccentric rotating mass is used to generate sinusoidal force. Multi stress and multi frequency modes are operated by adjusting eccentricity and speed of rotating mass. The instrument also has facility to adjust the static force imparted on the specimen. Deformation of the material is detected by a displacement sensor. This design satisfied all requirements of the testing standard.
item: Conference-Abstract
Determination of moisture content of wood using ultrasonic pulse velocity
(Department of Materials Science and Engineering, 2019-01) Vithanage, VSC; Wijesinghe, MPMC; Piyathilake, SAKVM; Sivahar, V; Sivahar, V; Sitinamaluwa, HS
Wood is one of the conventional materials still used in many engineering applications. As a natural material, it is subjected to dynamic property variations. One of the major reasons for the property variation of wood is the moisture absorption. The main aim of this research is to estimate the degree of decay in the compressive strength of selected wood types against the amount of moisture using ultrasound waves. Teak (Tectonagrandis), a hardwood and Pine (Pinusthaeda), a softwood are two types of wood which are commonly used in Sri Lankan wood industry. Samples of each wood type were kept for moisture absorption and the ultrasonic pulse velocities were measured in each sample. A 54 kHz normal probe was used. Through transmission technique was carried out in longitudinal and transverse directions. The corresponding compressive strength was also tested for each moisture level in the defined directions. In the transverse direction, ultrasonic velocity and compressive strength showed relatively lower values than those in the longitudinal direction. The ultrasound velocity was found to drop with the increase in moisture content. The rate at which the velocity drops changed at a particular moisture content. It was noted that this moisture content is the Fiber saturation point (FSP) of the wood tested. This phenomenon is common for both the wood types in both the directions. The fiber saturation point of each sample was confirmed with DSC (Differential Scanning Calorimetric) analysis. The established relationships can be used to estimate the compressive strength of wood nondestructively for a known moisture content.
item: Conference-Abstract
Determine the relationship between corrosion rate and grain size of low carbon steel
(Department of Materials Science and Engineering, University of Moratuwa., 2021-12) Sivasangaranathan, V; Sirinatha, DR; Sivahar, V; Abeygunawardana, AAGA
There are few studies on the effect of grain size on the corrosion rate of low carbon steel. In the current work, a series of grain sizes have been obtained in typical low-carbon steels through simple heat treatment. As we all know, grain refinement can improve strength and wear resistance. The inherent processing involved in grain refinement will change the volume and surface area of the material, resulting in changes in grain boundary density, orientation and residual stress. Ultimately, these surface changes will have an impact on the electrochemical behavior, thereby affecting the corrosion sensitivity. A large number of studies on the effect of grain size on corrosion have proved this, covering a variety of materials and test environments. However, the basic understanding of how grain refinement affects the corrosion resistance of steel, and more generally, how grain size affects the corrosion rate of low carbon steel, is very limited. The existing literature is often contradictory, even within the same steel category, and to a large extent lacks a consistent understanding of how grain size affects corrosion response. It is necessary to consider whether or how changes in grain size affect the behavior of specific steel in a specific environment.
item: Conference-Abstract
Development of a computer software for polymer composite mechanical properties analysis
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Mudalige, SP; Sanjeewa, PVGI; Weragoda, VSC; Sivahar, V
This research investigates the development of a software application designed for the analysis of polymer composites and the estimation of their mechanical properties, specifically the elastic modulus and tensile strength. In response to the need for accessible and efficient computer applications in composite analysis, this study focuses on developing a software which employs scanning electron microscopy (SEM) micrographs of the composites to extract relevant data. The software utilizes image processing techniques to accurately identify spherical particles within the composite and offers estimations for the elastic and shear modulus as well as tensile strength values. It is particularly suitable for the analysis of composites consisting of randomly oriented spherical particles, as well as those reinforced with short fibers. The mathematical models employed in the software, derived from previous calculations, allow for the estimation of the elastic modulus, shear modulus, and Poisson's ratio of the composite. The software also provides additional features to enhance its reliability and user experience. Furthermore, to ensure accuracy and reliability, the software underwent validation by comparing its predictions against literature-based real values. The developed software application addresses the need for accessible and efficient computer applications in the field of mechanical data extraction from polymer composites. It offers a user-friendly interface and advanced algorithms for analyzing SEM micrographs and extracting key mechanical properties quickly and efficiently. The software provides researchers and engineers with a valuable tool for efficient analysis and characterization of composite materials, contributing to advancements in the field of composite research.
item: Conference-Abstract
Development of a lab scale dynamic mechanical analyzer
(Department of Materials Science and Engineering, 2019-01) Rathnayaka, RMPC; Madushani, HDT; Weragoda, VSC; Sivahar, V; Sitinamaluwa, HS
Dynamic mechanical properties refer to the response of a material when it is subjected to a periodic strain. Dynamic mechanical analysis (DMA) is an important technique used to measure the mechanical and viscoelastic properties of materials such as thermoplastics, thermosets and elastomers. The aim of this research is to study the Dynamic Mechanical behavior of elastomer compounds by developing a lab-scale dynamic mechanical analyzer. The apparatus was designed to record a test specimen's reaction force when a systematically varying gradual strain development is applied. The phase difference between the applied strain and the material's response in terms of force was used to estimate the storage modulus and loss modulus to analyze the material properties. Furthermore, the dynamic modulus, dynamic loss modulus, and the mechanical damping coefficient of the elastomer could be estimated using the developed dynamic mechanical analyzer. The values obtained using the developed apparatus showed a fairly good agreement with the values for the same compound obtained from Prescott instruments ODR. The deviations were within 3.5%. One of the major shortcomings of the apparatus was the fact that the operating frequency was limited to IHz and there is no provision for carrying out measurements in varying temperature conditions.
item: Conference-Abstract
Development of a low cost, static light scattering based nano-particle size analyzer
(Society of Materials Engineering Students, Department of Materials Science and Engineering, University of Moratuwa, 2017-03) Anuradha, SKA; Ishan, HHA; Amarasinghe, DAS; Sivahar, V
A machine based on Static Light Scattering theories was developed for the cost effective and efficient Quality Control of the average particle size of nano-particles used in different manufacturing industries. In particular the instrument was adapted to measurement of carbon black filler used in rubber compounding. Carbon blacks are amorphous quasi graphitic particulates of the nanometer scale whose mean particle size affects the reinforcement, conductivity pigmentation and UV resistance properties of the rubber. The instrument would enable local rubber compounding companies to independently monitor and control the average particle size of the filler. The system is semi-autonomous and measures approximately 29cm × 23cm × 17.5cm and weighs approximately 4.2 kg. The instrument accepts a solution of nano-particles. Adjusts the solution concentration automaticallyand measures the scattered intensity of light which it used to calculate the particle size. The system comprises of a fluidics module that handles the pumping and dilution of solutions, an optics module that generates and detects the light and a control & power supply module that operates the other components and supplies the right voltages to them. These modules are housed in a corrosion protected steel frame and an aesthetically appealing enclosure. Key features of the instrument are a self diagnostic system, a modular structure, a graphical user interface with record keeping facility and extendibility to other particle size control applications. It is of a modular design and has been constructed with the ease of maintenance and accessibility to internal hardware, and manufacturability in mind. The components selection was based on the optimization of performance parameter, size and cost. Mechanical, thermal and vibration stabilities were considered in the design.
item: Conference-Abstract
Development of a photosensor based on photo dielectric effect of cadmium sulphide
(Department of Materials Science and Engineering, 2019-01) Kumari, TID; Jayasumana, MASD; Attygalle, D; Sivahar, V; Sitinamaluwa, HS
A photosensor is an electronic component that detects the presence of visible light, infrared transmission (IR), and/or ultraviolet (UV) energy. A photosensor which changes its electrical capacitance in the presence of visible light was developed based on the photo-dielectric effect of Cadmium Sulphide (CdS). This photosensor was fabricated by depositing a CdS thin film on Fluorine-doped Tin Oxide glass (FTO glass). FTO acts as the front electrical contact and an aluminum sheet acts as the back contact, where a 2.0)im - 3.0)im thick CdS thin film acts as the photo-dielectric material. Chemical bath deposition method was used for CdS fabrication and the CdS thin film with optimum photovoltaic and micro structural properties was obtained at a bath temperature interval of 40 - 45 °C, annealing temperature of 180-220 °C. Film thickness was varied by adjusting deposition time and the number of coatings. Thickness variations were determined using a Scanning Electron Microscope (SEM). The transmittance and absorbance spectra are recorded in the range of 200 nm - 1100 nm. CdS thin film fabricated under optimum conditions resulted in a bandgap in the range of 2.30 eV-2.40 eV, which is closely agreeing to the theoretical value of 2.42eV. The photo-capacitance and photoconductivity were measured in a frequency range of 1 kHz to 5 MHz in dark and illuminated conditions. The Cole-Cole plots were analyzed to identify the most sensitive operational frequency for the device.
item: Conference-Abstract
Development of a vibration and shock sensor using piezoelectric ceramics
(Department of Materials Science and Engineering, 2019-01) De Silva, HTTM; Dayananda, RKAS; Adikary, SU; Sivahar, V; Sitinamaluwa, HS
When buildings are exposed to vibration or shock, those buildings can be damaged partially or fully depending on the energy of vibration. Hence, quantitative analysis of building vibration has become popular among researchers. In this research, a vibration sensor was developed using a piezoelectric ceramic cantilever beam and a tip mass to confirm that the vibration frequency of the building does not exceed the cosmetic damage range. As the first step, a mathematical model was developed to calculate the resonance frequency of the cantilever beam with a tip mass. At the resonance frequency, maximum amplitude could be achieved resulting in a higher output voltage of the piezoelectric sensor. The developed mathematical model and finite element analysis were used to determine the accurate dimensions of the cantilever beam based piezoelectric sensor. According to the calculations, width, length and thickness of the piezoelectric material, copper beam and tip mass are 10x20x1, 10x100x0.3 and 10x30x3 mm respectively. Hence, the piezoelectric sensor output voltage was calculated using finite element analysis at the vibration frequency range that corresponds to the cosmetic damage. According to the calculations, threshold voltage level and frequency of the sensor to activate the alarm were 4.35 mv and 9.5 Hz respectively. Arduino software was used to analyze the output signal of the sensor. Vibration source was used to verify the calculation steps. Finally, liquid crystal display and small buzzer were added to show the frequency and give a warning when vibration frequency exceeds the required level.
item: Conference-Abstract
Development of an exhaled breath analyzer for early detection of diseases
(Department of Materials Science and Engineering, University of Moratuwa., 2023) Panawala, PSS; Tissera, PIU; Amarasinghe, DAS; Sivahar, V
Chronic Kidney Disease (CKD) represents a significant global health burden, with early detection being crucial for effective management and improved patient outcomes. This research focuses on the development of an Exhaled Breath Analyzer (EBA) as a non-invasive and potentially cost-effective tool for early detection of CKD. Ammonia (NH3) has been identified as a key marker in exhaled breath to diagnose CKD patients as the concentration of ammonia among healthy people is about 0.5-5 ppm and in CKD patients it can be more than 25 ppm. In this work, an ammonia gas sensor based on Polyaniline (PANI) was fabricated using a custom made Interdigitated capacitive sensor (IDC-S). PANI films were successfully deposited on the IDC-S using the solution casting method. The sensor responded to a low ammonia concentration of 50 ppm with a capacitance change of 10% with respect to capacitance in air in room temperature. Furthermore, the response of the sensor increased to 44% as the concentration increased to 300 ppm. This showed a good linear relationship between sensor response and ammonia concentration. Furthermore, the effect of relative humidity on the sensor was also studied and a significant change in capacitance of the sensor was observed with changing relative humidity levels. Moreover, the sensor response to a fixed ammonia concentration of 200 ppm at different humidity levels was studied and it diminished from 26% to 4% as the humidity level increased from 20% to 90%.
item: Conference-Abstract
Development of an exhaled breath analyzer for early detection of diseases
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Panawala, PSS; Tissera, PLU; Amarasinghe, DAS; Sivahar, V
Chronic Kidney Disease (CKD) represents a significant global health burden, with early detection being crucial for effective management and improved patient outcomes. This research focuses on the development of an Exhaled Breath Analyzer (EBA) as a non-invasive and potentially cost-effective tool for early detection of CKD. Ammonia (NH3) has been identified as a key marker in exhaled breath to diagnose CKD patients as the concentration of ammonia among healthy people is about 0.5-5 ppm and in CKD patients it can be more than 25 ppm. In this work, an ammonia gas sensor based on Polyaniline (PANI) was fabricated using a custom made Interdigitated capacitive sensor (IDC-S). PANI films were successfully deposited on the IDC-S using the solution casting method. The sensor responded to a low ammonia concentration of 50 ppm with a capacitance change of 10% with respect to capacitance in air in room temperature. Furthermore, the response of the sensor increased to 44% as the concentration increased to 300 ppm. This showed a good linear relationship between sensor response and ammonia concentration. Furthermore, the effect of relative humidity on the sensor was also studied and a significant change in capacitance of the sensor was observed with changing relative humidity levels. Moreover, the sensor response to a fixed ammonia concentration of 200 ppm at different humidity levels was studied and it diminished from 26% to 4% as the humidity level increased from 20% to 90%.
item: Conference-Abstract
Development of antimicrobial materials for food packaging applications
(Society of Materials Engineering Students, Department of Materials Science and Engineering, University of Moratuwa, 2017-03) Senarath, SMNS; Madushani, SPA; Samarasekara, AMPB; Amarasinghe, DAS; Sivahar, V
The rising demand to increase fresh food shelf life as well as the need of protection against foodborne diseases urged the development of antimicrobial food packaging. Nanomaterials have increasingly being used in food packaging applications in recent years due to their extraordinary properties when compared to bulk materials. Nanoparticles provide signi? cant antimicrobial properties in different environmental conditions. Nowadays, there is heighten attention in designing nano particles incorporated food packaging with the introduction of nanotechnology. Silver nanoparticles (AgNPs) based antimicrobial packaging is an innovative form of food packaging used to extend shelf-life of food and reduce the risk of pathogens. AgNPs are one of the most powerful antimicrobial agents which can be used for increasing shelf life of foods due to its capacity to eliminate infectious micro-organisms. The present research work is based on the preparation of silver nanoparticles incorporated coating for polymer based packaging components. Nano Silver impregnated cross-linked polyvinyl alcohol coating was synthesized and applied on the polymer surface. In this study, wettability of the polymer surface was enhanced by a UV treatment. Contact angle was measured to confirmation of the wettability. The adhesion of the coating to polymer was obtained as load required to peel off the coating. Optimum UV treatment time was selected by using contact angle measurements and load required to peel off the coating. Thermal degradation of cross-linked Nano silver coating was determined using thermo gravimetric analysis. Presence of silver nanoparticles in the coating was confirmed by Surface Plasmon Resonance (SPR) and Scanning Electron Microscopy (SEM). The nano silver incorporated polymer was tested for its biocidal action against model bacteria Escherichia coli using zone inhibition and food contain in nano silver coated containers. Developed nano silver incorporated polymer based food packaging products showed antimicrobial properties. This developed product can be used to improve the quality of the food and extend shelf life especially in food packaging applications.
item: Conference-Abstract
Development of cement, sand and sawdust based composite material to use as plaster for walls
(Department of Materials Science and Engineering, 2019-01) Ekanayaka, EMCHB; Fernando, KKA; Udayakumara, SV; Sivahar, V; Sitinamaluwa, HS
With the arisen development around the world, the demand for natural construction materials has been increased. Increasing consumption levels decrease the amount of available natural resources. The importance of material efficiency and the need to improve it can be studied from several perspectives. Limited availability or scarcity of materials may lead to threats to the economy, and the production processes of materials can have significant environmental impacts. This study was concentrated on the use of sawdust as a partial replacement for fine aggregates in cement-based wall plaster material. Mahogany sawdust produced in local timber mills was selected for the study. Sawdust was incorporated into the plaster mixture in the raw form as well as in burnt form (saw dust ash). Composites were prepared by incorporating 5% and 10% saw dust by weight and sawdust ash by weight. Prepared composites were tested for flexural strength and tensile strength according to BS EN 1015 standard. Lee's disc method was used to compare the thermal properties of the composites. Composite with 5% saw dust ash showed better properties compared to the composites with other sawdust combinations.
item: Conference-Abstract
Development of composite material based on waste paper and waste LDPE for ceiling sheets.
(Society of Materials Engineering Students, Department of Materials Science and Engineering, University of Moratuwa, 2017-03) Pathirage, TG; Munasinghe, DKR; Udayakumara, SV; Sivahar, V
In Sri Lanka used papers are re-utilized only for paper and board industry. However ,collecting used papers and recycling them are still highly inhomogeneous. Therefore major part of used papers become garbage. Used plastics are another agent that produce many environmental issues. Major part of waste plastics consist low density polyethylene (LDPE) which is mostly used for packaging items. This study was aimed to develop light weight composite material based on waste paper and waste LDPE specially for ceiling sheets. Use of waste as a starting materials for composite will contributes to savings of natural materials, reduction of energy and chemicals consumption, reduction of the impact on fresh water and improvement of waste management strategies. The composites with various compositions were prepared by hot compression moulding by varying weight percentage of paper and LDPE. . Tensile strength, modulus of rupture, hardness, thickness swelling, linear swelling , water absorption and thermal conductivity were determined for all compositions according to the ASTM standards. According to the test results water absorption and swelling gradually increased. However all the composite samples showed less thermal conductivity , less density and better mechanical properties than asbestos which is the mostly used material for ceiling sheets. Therefore in future paper based composites will become a cheaper replacement for ceiling materials.
item: Conference-Abstract
Development of cost-effective cement-based ceiling sheet with the addition of waste foundry dust
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Mathuran, T; Thulaanchan, K; Fernanado, TN; De Silva, GIP; Sivahar, V
Ceiling sheets are predominantly produced with the addition of asbestos; however, asbestos has been identified as a carcinogenic material. Hence, there is pressing demand for alternative materials to produce ceiling sheets. Waste Foundry Dust (WFD) is a byproduct of metal sand casting process, and there is no effective permanent solution for disposal of the WFD. In this study, the possibility of manufacturing cement-based ceiling sheets with addition of WFD is investigated as a low cost and healty alternative for asbestos based ceiling sheets. Firstly, Ordinary Portland Cement (OPC) was mixed with WFD amount of 30%, 40%, 50% & 60% of total weight to prepare the material. Then, sheets were prepared using compression molding, by applying 2 tons per inch pressure. Also, another set of samples were made by replacing 3 wt% of cement with bentonite, with the same WFD amounts. A series of experiments were conducted to measure flexural strength, thermal conductivity, and water absorption of the prepared samples after 28 days of curing period. All the sample preparations and testing were done according to ASTM C-1185 standard. The results show that the strength and thermal conductivity decrease with increase of WFD while water absorption increase with increasing WFD. Here bentonite is used as binder to increase the binding property, hence improve the properties of prepared samples. WFD mainly acts as filler material to reduce the cost and reduce the adverse effect on environment.