콘크리트 침목 재활용 순환골재를 활용한 흡음자재의 성능평가

초록

This study investigates the acoustic and mechanical properties of sound-absorbing materials fabricated using recycled aggregates derived from discarded railway sleepers . Fine aggregates were classified into three grades- H, M, and L - based on pretreatment conditions, and their structural and acoustic characteristics were analyzed in relation to the residual fine powder content. Mechanical tests revealed that the L-grade specimens, containing a higher amount of fine powder, exhibited the highest compressive and flexural strengths. X-ray micro-computed tomography (Micro-CT) analysis confirmed a densely packed internal structure in the L-grade samples. The impedance tube measurements demonstrated that the L-grade specimen achieved superior sound absorption across a broad frequency range, with a Noise Reduction Coefficient (NRC) of approximately 0.45. These results indicate that fine powder removal through pretreatment has minimal impact on improving either mechanical or acoustic performance. Consequently, the findings highlight the potential for high-value recycling of construction waste materials, such as railway concrete sleepers, in noise control applications within transportation and civil infrastructure systems.

키워드