For acoustic applications such as theaters, cinema halls, auditoriums the data on acoustic properties i.e. sound absorption coefficient and sound transmission loss are required to evaluate the acoustic behavior of panel products and to facilitate the necessary design computations. Fibre boards are widely used in private and commercial buildings, but not much data are available on acoustic efficiency of fibre boards. The study was carried using acoustic pulse tester based on standing wave method for evaluating sound absorption coefficient. Wood fibre boards of different densities ranging from 200 to 800 kg/m 3 were taken and their sound absorption coefficients at frequencies ranging from 125 Hz to 4000 Hz were evaluated in third octave band. Noise reduction coefficient of the samples was also computed. From the study, it is observed that low density fibre board possess high sound absorption coefficient and noise reduction coefficient when compared with high density fibre boards. It was seen that sound absorption coefficient increases with decrease in density and vice versa.

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Waste tires have emerged as a severe environmental threat worldwide as they create a number of disposal and landfill burden issues. In the present study, environmental pollutant crump rubber derived from waste discarded tires was reinforced with epoxy resin and prepared by means of an open-mold casting method to assess its mechanical properties. The impact of crump rubber content (0, 10, 20 and 30 vol.%) on the mechanical behavior of the composites was assessed using three-point bending tests at a constant strain rate of 0.1 and 0.01 mm/s. The stress–strain profiles of the 0.01 mm/s specimens revealed higher strains to failure compared with the 0.1 mm/s tested specimens and all the specimens showed brittle failure. Irrespective of the strain rates, tests revealed a marginal increase in the strength values of the composites and a significant increase in the modulus of all the composites compared with neat epoxy specimens. The results suggest that crump rubber can be effectively used in utilitarian composites requiring good flexural modulus and strength properties. Crump rubber epoxy composites with 30 vol.% of crump rubber showed higher modulus and strength compared with neat epoxy and other composites owing to the toughening phase induced by the crump rubber particles. The failure and fracture features of the specimens were analyzed using scanning electron microscopy.

Effect of parameters affecting solid particle erosion of crumb rubber epoxy composite is investigated. Five important process parameters—impact velocity, impingement angle, standoff distance, erodent size, and crumb rubber content—are taken into consideration. Erosion rate and erosion efficiency are included as the chief objectives. The Taguchi coupled gray relational analysis type statistical model is implemented to study interaction, parameters' effect on responses, and optimized parameters. ANOVA and regression model affirmed impingement angle and crumb rubber content play a significant role to minimize the erosion. Validity of the proposed model is justified with the standard probability plot and R2 value. A confirmation experiment conducted with A2B2C3D3E3 condition registers noticeable enhancement in GRG to the tune of 0.0893.

Quasi static compressive response of crumb rubber-epoxy composites was examined by varying the crumb rubber composition (0, 10, 20 and 30 vol.%). All the composites, irrespective of the strain rates, depict elastic regions tailed by a wide plateau area that is credited with the densification of rubber particulates. Higher strains to failure of composites were revealed as compared with neat epoxy signifying higher energy absorption ability of constituents. The modulus of elasticity of composites was noted to be lower than neat epoxy specimens, irrespective of the strain rates. Irrespective of strain rates, the strength of all the composites were inferior to neat epoxy specimens. Energy absorption of EC-30 was higher compared to EC-20 and EC-10 and noted to be increased in the range of 6–14% for 0.1 mm/min strain rate while it increases in the range of 5–9% for 0.01 mm/min strain rate, respectively. Rubber-toughening mechanism was credited with the increase in energy absorption of composites. Higher energy absorption of composites was mainly due to higher strain realisation indicating more deformation ability. Fracture features of specimens were analysed by scanning electron microscope.

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