Acoustic Properties of Concrete

Acoustic properties have great importance in many building. This characteristics are mainly influenced by types of structure, construction details and properties of materials used in construction.

Acoustic Properties of a Building Materials
Generally, two properties are important in acoustic performance. These are-

• Sound absorption
• Sound transmission

Sound Absorption

energy created by sound waves is partly absorbed and partly reflected necessitating a sound absorption co-efficient, defining absorbed proportion of sound energy when hit a surface. Sometimes, a term "noise reduction coefficient" is used to define the average of sound absorption coefficients at 250, 500, 1000 and 2000 Hz is octave steps. This values are for

• Normal wt. aggregate conc. having medium texture- 0.27
• Expended shale aggregate - 0.45

When airflow is possible sound convert into hear by friction resulting large increase in sound absorption and this airflow depends on structure type, texure and porosity. Thus concrete made with porous light weight aggregate shows higher sound absorption than the cellular concrete contains discrete air bubbles.

Sound Transmission:It is measured in decibels(dB). the loss occur in sound transmission is a difference between the incident sound energy and the transmitted sound energy (which radiates into an adjoining room).