An innovative approach for the development of sound absorbing material using industrial wastes

Abstract

For sound absorbing panels as noise barriers, a research study is carried out to design and develop a composite mix using industrial waste as Fly Ash (FA), Waste Tyre Rubber (WTR) granules with cement. The design mix is prepared in two stages. The first stage involves blending of Ordinary Portland Cement (OPC) by gradually increasing the WTR percentage in the mixture. In the second stage of the study, the WTR content was kept constant while the percentage of cement and FA varied based on the required binding properties of cement for further acoustical enhancement. Evaluation of engineering and acoustic properties conveyed an increment of 470 % in the void ratio, as well as a 192.7 % and 236 % increase in Average Sound Absorption Coefficient (ASAC) and Noise Reduction Coefficient (NRC) respectively in the first phase of the study. The void ratio is further enhanced by 18.8 % with a mere decrement of 3.6 % in the compressive strength and an observed increase in Sound Absorption Coefficient (SAC) by 18.2 % in the second stage of the study. The optimal design mix prepared by 50 % WTR and 40 % FA with 10 % of cement provides efficient acoustic properties in the frequency range 500–1600 Hz and 2500–6300 Hz. The composite matrix is cost-effective and provides engineering properties for developing sound absorbing panels as noise barriers specially to control traffic noise and honking. The utilization of industrial waste in the composite mix renders threefold environmental advantages i.e. reduction in waste volume by promoting recycling, no chemical treatment and also mitigation of noise pollution through noise barriers.