Sound transmission through rigid porous materials with and without perforations

Environmental noise is a general harmful public issue in the built environment. To reduce harmful factors of the noise, porous rigid materials such as concrete are usually utilised to reduce noise in the build environment. Acoustical properties of concrete are governed by absorption mechanisms, type of aggregates, size, distribution of pores and changes in concrete design. Normal and glass-based concrete have low absorption coefficients while aerated, foamed, polymer and polyurethane concrete have higher absorption coefficients. Concrete samples that are mixed with basalt fibres are developed with and without perforation. In this paper, the acoustical properties of concrete samples are investigated to determine their usability as sound reflectors, sound absorbers, and as water absorbers to prevent flooding. Concrete samples are tested in impedance tube using transfer function method to determine their absorption coefficient and transmission loss.