Research on the Development and Application of New Eco-Friendly Noise Barrier Materials Based on Recycled Waste

Traffic noise adversely affects residents near expressways, calling for sustainable noise mitigation solutions. This study developed three eco-friendly sound-absorbing panels from sand, industrial slag, and microporous ceramics. By optimizing aggregate gradation, the influence of porosity and flow resistivity on absorption coefficients was analyzed to determine optimal mix ratios. The panels were integrated into perforated metal noise barriers and evaluated through reverberation room and sound insulation tests. Field simulations using SoundPLAN for a residential project in Taizhou validated real-world performance. Results showed that slag panels achieved a Noise Reduction Coefficient (NRC) of 0.70, while sand and ceramic panels both reached 0.55. All configurations maintained a weighted sound reduction index (Rw) of 25–26 dB. Empirical simulations confirmed that a 2.5 m high barrier keeps noise levels within the 60 dB limit. Compared with traditional glass wool, these inorganic panels offer comparable noise reduction, superior non-combustibility, and better weather resistance, making them effective for frequency-specific noise control in urban engineering applications.