Advanced investigation using the EApu method on the effect of quantitation and particle size of charcoal in clay bricks on sound absorption coefficient

摘要

Due to rapid urbanization, noise pollution becomes the environmental problems in Asia and their harmful effects on people's health are undeniable. Reducing noise by absorption material is a good alternative. Bricks are one of the most common construction supplies in Asia because of the cost. Therefore, this study aims to apply for the authors' EApu method (sound absorption characteristics measurement method using ensemble averaging technique and a pressure-velocity sensor) to clay bricks to clarify the relationship between the sound absorption coefficient and the amount and size of an additive. The measurement was conducted in a reverberation room following the procedure presented in our previous papers. Measured bricks have four types of porous that were designed by selecting from different sizes of charcoal that was added into the specimens in the amounts of 0-30%wt. Next, samples were fired at 1100°C and tested for sound absorption coefficient. Lastly, the microstructure analysis was conducted. The results indicated that the larger size and higher percentage of charcoal added in fired clay bricks presented the excellent absorption coefficient. Such a detailed investigation can be performed by the EApu method, and the EApu method helps material designing process become more accessible to control sound absorption.