On the acoustical performance of eco-friendly cementitious composite with recycled fine rubber particles

Abstract

Enhancing the sound absorption capacity of cement-matrix composites with fine particles of rubber tires is studied. Ordinary Portland Cement (OPC)/ waste rubber particles (WRP) were blended with the ratios of 100/0, 95/5, 85/15, and 75/25 wt%, respectively, then mixed with water. The sound absorption coefficient (SAC) and noise reduction coefficient (NRC) were assessed using the two microphones method. The specific sound transmission loss (SSTL) was calculated to show the correlation between the STL and the density of the prepared samples. The WRP dispersion in the matrix of the composite was analyzed using a digital microscope and ImageJ program to investigate the homogeneity of dispersion. The morphology and microstructure of the formed hydration products were examined by environmental scanning electron microscope (ESEM). The Physicomechanical properties: compressive strength, water absorption, apparent porosity, and bulk density of the hardened composites were measured after 28-days of hydration. The results showed that replacement of OPC with 5, 15, 25 wt% WRP led to an increased sound absorption compared to the control sample. Increasing the dose of the WRP caused the reduction of voids content in the hardened cement pastes. The NRC values were improved by 109, 27.3, and 63.6% than the control sample for 5, 15, and 25 wt% WRP, respectively.