Influence of cement flow and aggregate type on the mechanical and acoustic characteristics of porous concrete

Abstract

The influence of cement flow and aggregate type on the mechanical and acoustic characteristics of porous concrete is systematically investigated in the present study. Three levels of cement flow (80%, 110%, and 140%) and five types of aggregates (normal aggregates of 8-13 mm and 13-19 mm and lightweight aggregates of 4-8 mm, 8-12 mm, and 12-19 mm) are used, and effects of the application of AE admixtures in paste were also studied. Single-layered and double-layered porous concrete specimens are fabricated to examine the effect of different layer configuration on the acoustic characteristics. For the purpose of comparison, the void ratio, compressive strength, and sound absorption coefficient of the specimens are used as evaluation parameters. Based on the findings of the study, a sound absorbing porous concrete with a maximum absorption coefficient of approximately 1.00 is developed, and the minimum absorption coefficient of the 'double-layered porous concrete' structure is shown to be more than 0.60 with a frequency of 400 Hz or above, considering the tolerant error. (C) 2010 Elsevier Ltd. All rights reserved.