Research Progress in 3D-Printed Noise-Reducing Concrete Materials

As environmental noise pollution becomes increasingly severe, concrete noise barriers have been widely used in noise control applications due to their excellent durability and cost-effectiveness. However, conventional concrete barriers still have shortcomings in sound absorption and insulation performance, making it difficult to meet the comprehensive demands of lightweight design, functional integration, and environmental sustainability simultaneously. Existing research has improved the noise reduction capability of concrete at the material level by incorporating components such as foaming agents and porous lightweight aggregates into cement-based systems. By adjusting material density, porosity, and pore connectivity, the pore structure and acoustic energy dissipation mechanism of the material have been optimized. On this basis, 3D printing provides a new way to achieve complex geometric designs, lightweight manufacturing, and structural personalization for noise-reducing elements. The directional interconnected pore networks and unique interlayer interface characteristics formed during the printing process can effectively extend the sound wave propagation paths and enhance energy dissipation, thus achieving acoustic performance optimization at the structural level. This article systematically summarizes the key factors and their control strategies affecting the noise reduction performance of concrete, focuses on analyzing the mechanisms by which 3D printing processes regulate pore distribution, interlayer interfaces, and surface textures, and summarizes relevant engineering application cases. Existing research indicates that properly designed 3D-printed concrete structure exhibits significant advantages in mid-to-low-frequency sound absorption, while further targeted optimization of acoustic performance can be achieved by coordinated regulation of geometric configurations and surface textures. In addition, 3D-printed noise-reducing concrete holds significant application potential in road noise barriers and architectural acoustics, though it still faces technical challenges such as material printability, interlayer bond strength and long-term service performance. Future research should focus on the utilization of green and low-carbon raw materials, multi-scale structural design, and durability assessment to promote the high-performance development and engineering application of 3D-printed noise-reducing concrete.