Acoustic properties of cenosphere reinforced cement and asphalt concrete

A detailed experimental study has been conducted to determine the effect of adding hollow ceramic-micro balloons, also known as cenospheres, on the acoustic properties of cement matrix and asphalt concrete. The motivation for this study was to explore the feasibility of using cenospheres in developing lightweight sound absorbing structural materials. Cement and asphalt concrete specimens with different volume fractions of cenospheres and varying diameter and thickness were tested to determine their acoustic characteristics over the range of frequencies (0-4000 Hz). Experimental results showed that a 40% volume fraction addition of cenospheres to cement matrix increased the Noise Reduction Coefficient by 100%. In contrast to cenosphere rich cement, the sound absorption coefficient of asphalt concrete decreased with an increase of cenosphere, volume fraction.