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Item With a view to study the response to impacts, epoxy-fly ash systems, with filler particles treated with silane material to their surface were fabricated. The test coupons made from the cured thermoset cast slabs were subjected to impact in an instrumented test set up, where, provision existed for recording both load and total energy absorbed with respect to time. The investigation shows that the crack path shift was highest for unreinforced ones, which, display river marks.(Carl Hanser Verlag, Correlating failure features to impact data in epoxy systems without and with silane surface bearing fly ash filler particles in varying amounts; Korrelation von versagensmerkmalen und schlagzähigkeitsdaten in epoxidsystemen mit und ohne silanbeschichtete flugascheteilchen in unterschiedlichen volumenanteilen) Kishore; Ravikumar, N.L.; Kulkarni, S.M.2004Item Epoxy systems with and without different volume fractions of fly ash particulate fillers are made and their absorption due to immersion in saline water maintained at room temperature are established through weight measurements recorded up to 100h. The 100-h exposed samples are additionally subjected to compression tests to evaluate the strength. The results show that both neat epoxy and fly ash-bearing composites exhibit differing levels of aqueous medium absorption - it being less in ash-free samples. When the ash content in the system is large, the absorption levels are high. The data further revealed that the unexposed samples generally record an increasing strength value with ash content. However, for the exposed cases, a reversal in trend with the ash content is noticed. Attempts to explain these differing trends are made in this work by analyzing the features observed on the surface of compression-failed samples using fractography employing scanning electron microscopy (SEM). © 2005 Sage Publications.(Compression strength of saline water-exposed epoxy system containing fly ash particles) Kishore; Barpanda, P.; Kulkarni, S.M.2005Item Performance characteristics of the particulates scrubbing in a counter-current spray-column(2008) Mohan, B.R.; Biswas, S.; Meikap, B.C.Spray scrubbers are being widely used for off gas cleaning in chemical process industries due to its various advantages like low-pressure drop and simplicity. A pilot plant counter-current spray-column wet scrubber has been conceived, designed and fabricated. Experimental investigations were conducted to quantify the performances of a counter-current spray-column for scrubbing the particulates from the gaseous waste stream. Performance characteristics of the air-blast atomizing spray-column have been evaluated on the basis of the fly-ash (particulates) collection efficiencies within the stability range of the column. A maximum efficiency of 94.23% is achieved for gas and liquid flow rate of 5.084 × 10-3 Nm3/s and 33.34 × 10-6 m3/s, respectively. Results further show that Inlet solid loading effects positively in increasing the collection efficiency. Experimental results were further analyzed in terms of various pertinent variables of the system and a simplified correlation has been proposed. The predicted values agreed well with the experimental data obtained. A maximum difference of 17-18% was found towards higher liquid rates, rest showing a very minimum percentage of error and standard deviations between the experimental and the predicted values. © 2007 Elsevier B.V. All rights reserved.Item Sliding wear behaviour of an epoxy system reinforced with particulate fly ash filler(Adcotec Ltd. info@sagepub.co.uk, 2009) Barpanda, P.; Kulkarni, S.M.; KishoreNeat epoxy and epoxy containing different volume fraction of as received fy ash particulate fller bearing composites were cast, sectioned and subjected to pin-on-disk tests for evaluating the wear behaviour. The wear tests were conducted for 1 kilometre distance under 1 kg load for sliding velocity ranging from 1 to 5 m/s. The results showed that both neat epoxy and fy ash bearing composites exhibit differing magnitudes of wear loss, it being highest for unreinforced neat epoxy system. The data trends point to the fact that wears loss decreases with increasing content of fy ash in composites. To explain these differences, the wear surfaces were examined under scanning electron microscope and the features thus observed were correlated with the mechanical data.Item Mechanical properties of fly ash reinforced aluminium alloy (Al6061) composites(2011) Anilkumar, H.C.; Hebbar, H.S.; Ravishankar, K.S.The results of an experimental investigation of the mechanical properties of fly ash reinforced aluminium alloy (Al 6061) composites samples, processed by stir casting route are reported in this paper. Three sets of composites with fly ash particle sizes of 4-25, 45-50 and 75-100 ?m were used. The particle size ranges chosen as the said particle sizes were available more by weight fraction when sieve analysis was conducted on the sample collected for experiments and also the ones for which results are not reported. Each set had three types of composite samples with the reinforcement weight fractions of 10, 15 and 20%. The mechanical properties studied were the tensile strength, compressive strength, ductility and hardness. Unreinforced Al6061 samples were also tested for the same properties. It was found that the tensile strength, compressive strength and hardness of the aluminium alloy (Al 6061) composites decreased with the increase in particle size of reinforced fly ash. Increase in the weight fractions of the fly ash particles increases the ultimate tensile strength, compressive strength, hardness and decreases the ductility of the composite. The scanning electron micrographs of the samples indicated uniform distribution of the fly ash particles in the matrix without any voids.Item High temperature performance of self-compacting high-volume fly ash concrete mixes(2011) Amrutha; Nayak, G.; Narasimhan, M.C.; Rajeeva, S.V.Quite often, concrete in structures is likely to get exposed to high temperatures, including an incident of fire. The strength-retention properties of concrete after such an exposure are of great importance in terms of the serviceability of buildings. This paper presents an experimental study on the strength retention and impermeability aspects of a set of self compacting, high-volume fly ash concrete mixes under elevated temperatures. Five selfcompacting concrete mixes with a higher 60% level of cement replacement with fly-ash, are designed and the effects of elevated temperatures, in the range of 200-800 C, on the physical, mechanical and durability properties of these mixes are assessed. The assessment is in terms of the weight losses and the reduction in the compressive strengths of concrete cubes and split tensile strengths of concrete cylinders. The durability characteristics are assessed in terms of RCPT test results on these mixes. Performances of these self compacting concrete mixes (SCC) at elevated temperatures are also compared with two normally-vibrated concrete mixes (NCs) of an equivalent M30 strength grade. Test results indicate that weight of the specimens significantly get reduced with an increase in the level of elevated temperature, with sharp variations beyond 600 C. The experimental results also show that large improvements against chloride-ion penetration and better strength-retention at higher temperatures can be realized with self-compacting high-volume fly-ash concrete mixes additionally admixed with GGBFS and silica fume.Item Study on the strength parameters of high volume fly ash concrete and geopolymer concrete(2011) Shetty, A.; Anand, V.R.; Hegde, P.Concrete has been the most preferred construction material. It is being increasingly used day by day all over the world due to its versatility, mould ability and high compressive strength. But the large-scale production of cement is causing environmental problems on one hand and the unrestricted depletion of natural resources on the other. So the issue of sustainable development in concrete construction is addressed in this paper through development of concrete mixes by replacing certain percentage of cement with fly ash. Trials on concrete mixes with replacement of 40%, 50%, 60% and 70% of cement with fly ash are carried out and the results depict that at the replacement level of 40% cement by fly ash, the required strength is achieved. It is also observed that the rate of early strength gain is retarded as the percentage replacement of cement increases. But in case of Geopolymer concrete (100% replacement of cement by fly ash) under a curing temperature around 600C and above, the strength gain rate is very high in initial stages. It is observed that design strength is achieved within 28 hours of oven curing. © 2011 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Behavior of sandwich beams with functionally graded rubber core in three point bending(2011) Doddamani, M.R.; Kulkarni, S.M.; KishoreThe three-point bending behavior of sandwich beams made up of jute epoxy skins and piecewise linear functionally graded (FG) rubber core reinforced with fly ash filler is investigated. This work studies the influence of the parameters such as weight fraction of fly ash, core to thickness ratio, and orientation of jute on specific bending modulus and strength. The load displacement response of the sandwich is traced to evaluate the specific modulus and strength. FG core samples are prepared by using conventional casting technique and sandwich by hand layup. Presence of gradation is quantified experimentally. Results of bending test indicate that specific modulus and strength are primarily governed by filler content and core to sandwich thickness ratio. FG sandwiches with different gradation configurations (uniform, linear, and piecewise linear) are modeled using finite element analysis (ANSYS 5.4) to evaluate specific strength which is subsequently compared with the experimental results and the best gradation configuration is presented. © 2011 Society of Plastics Engineers.Item Extruded poly(ethylene-co-octene)/fly ash composites - Value added products from an environmental pollutant(Kluwer Academic Publishers, 2012) Anandhan, S.; Sundar, S.M.; Senthil, T.; Mahendran, A.R.; Shibulal, G.S.Fly ash (FA) is a by-product generated during combustion of coal and has caused serious environmental concerns. In an effort to utilize FA beneficially, we developed composites from an ethylene-octene random copolymer (EOC) and unmodified as well as surfacemodified class-F fly ash (MFA) by twin screw extrusion. Addition of 20 wt% of MFA to EOC improves its tensile strength by 150%; also, MFA improves stress at 100% and 300% strains (M100 and M300) of EOC. Thermal stability of EOC matrix is appreciably improved by the addition of either FA or MFA, while the melting behavior is not appreciably influenced by either. Fractography study reveals an improved adhesion between the EOC and MFA particles up to a filler loading of 20%, beyond which the adhesion between EOC and MFA is weakened causing a reduction in mechanical properties. The 'flammable' nature of EOC changes to 'self extinguishing' on addition of even 10 wt% of FA or MFA, as found out from LOI study. © Springer Science+Business Media B.V. 2012.