Building Acoustics

262 Building acoustics

given for R and Ln by Equations (6.74) and (6.106) we get, as expected, the same result
as in Equation (6.129).

Figure 6.33 The sum of impact sound pressure level and sound reduction index, calculated for two types of
floor. 1) Lightweight concrete floor, 175 mm thick with 60 mm concrete top cover and 2) Hollow concrete
floor, 260 mm thick. The latter is also measured with an added lightweight floating floor (chipboard on elastic
layer).

6.7 References

EN 12354–1: 2000, Building acoustics – Estimation of acoustic performance of buildings
from the performance of elements. Part 1: Airborne sound insulation between
rooms.
EN 12354–2: 2000, Building acoustics – Estimation of acoustic performance of buildings
from the performance of elements. Part 2: Impact sound insulation between rooms.
ISO 140–3: 1995, Acoustics – Measurements of sound insulation in buildings and of
building elements. Part 3: Laboratory measurements of airborne sound insulation of
building elements.

63 125 250 500 1000 2000 4000

Frequency (Hz)

90

100

110

120

130

140

150

R

+

L

(dB)n

Lightweight concrete

Hollow concrete

Predicted

Hollow conc. + top floor