Improvement of the Acoustic Attenuation of Plaster Composites by the Addition of Short-Fibre Reinforcement

Table 2

Typical physical properties of typical materials [26, 27].

Material	Density (kg m^−3)	E (Pa)	c (m s^^−1)	Z (N·s·m^−3)	Absorption (−)
Air	1.21	—	344	4.14 × 10^2	—
Rubber	900	4.4 × 10^4	70	6.3 × 10^4	0.02–1
Concrete	2300	1.0 × 10^10	3100	7.1 × 10^6	0.007
Aerated concrete	900	2.9 × 10^9	1800	1.6 × 10^6	0.005–0.012
Bricks	2000	1.6 × 10^10	2800	5.6 × 10^6	0.009–0.1
Wood	650	1.0 × 10^10	3900	2.5 × 10^6	0.015
Aluminium	2700	6.2 × 10^10	4800	1.3 × 10^7	7.1 × 10^−10
Steel	7850	2.6 × 10^11	5750	4.5 × 10^7	1.1 × 10^−4