Linking Micro Structure to Sound Absorption: An Experimental Study on Lime Based Plasters
Regular paper
Middle East Technical University
Wednesday 3 june, 2015, 14:40 - 15:00
0.7 Lisbon (47)
Abstract:
In this paper, the relation between pore structure characteristics and sound absorption performance of lime based plasters is discussed. Lime based plasters have been used in buildings since ancient times. Compared to contemporary cement based plasters, lime based plasters have higher breathing ability and compatible mechanical characteristics because of their flexibility. These performance characteristics are closely related to the pore structure of lime based plasters. In order to find out the role of this specific pore structure on sound absorption, a systematic experimental survey was carried out on the plasters where lime is used as a binding material. Various amounts of lime, pozzolanic additive, aggregate and water were mixed to prepare plaster samples having distinct physical properties like open porosity, density and modulus of elasticity. Sound absorption coefficients of the plaster samples were measured by an impedance tube. The samples were then analysed by microscopic observations and image analyses of cross sections in order to define the pore structure such as pore shape, average pore size and pore size distribution. At the end, the porosity properties of lime-based plaster samples were compared to expose key differences that may affect the sound absorption characteristics of these plaster samples.