Sound Absorption Coefficient and Young's Modulus of Concrete

Speaking and listening are the primary communication modes in most educational settings, and good acoustical qualities are essential in classrooms and other learning spaces in which speech communication is an important part of the learning process. However, the acoustical properties of classrooms are often the "forgotten variables" in ensuring students' academic success, particularly for students with unique communication or educational needs (Crum and Matkin 1976). Concrete is a common material found in most typical Filipino houses and buildings, especially school classrooms. One way of improving the quality of concrete is through the addition of admixtures. In this study, the researcher determined the effects of admixtures, such as the locally produced and abundant agricultural by-products (corn husk, coconut coir, and rice hulls) on the sound absorption characteristics and Young's modulus of concrete. The sound absorption coefficient was measured using the two-microphone impedance tube for the transfer function method while an improvised center-point loading procedure was used in determining the Young's moduli of the concrete samples.