2. CALCULUL ACUSTIC 1. Analiza zona de zi etaj V= volumul incaperii

T= timpul de reverberatie masurat conform stas 6691/1-70 [s]

S= suprafata fiecarui element de constructie a incaperii [mp]

A= coefficient de absorbtie al materialelor utilizate la finisaje

Si=30.50m2

V=85.40 m3

H=2.80 m

Calculul duratei de reverberatie T in zona de zi

T=0.161*V/A [s]

Unde:

V=volumul incaperii [m3]

A= aria de absorbtie echivalenta [m2]

A= ii S* j

1. Date generale: L=6.36m

l= 4.81m

S=30.50 m2

H=2.80m

V=85.40 m3

2. Calculul suprafetelor (finisate) Stencuiala=(6.36*2.8-1.10*2.20)+4.81*2.8-(2.00*1.70+3.76)+(4.81+6.36)*2.8= 55.17m

2

Spardoseala-parchet=30.50

Susi=2.1*0.90=1.89 m2

Sfereastra=1.05*1.70+2.00*1.70=5.12m2

Sdulap=2*(1.2*3+1.1+0.40)=10.20m2

S draperie =(2.4+2.4)*2.4=11.52m2

S canapele =2.4*0.9+4*0.43*0.43*3.1415=4.48m2

S masa =1.2*0.7=0.84m2

S sezlong =1.80*0.65=1.17m2

S plafon =30.50

Denumire

material

S

[m2]

125 250 500 1000 2000 4000

*S *S *S *S *S *S

Tencuiala 55.17 0,02 1,103 0,02 1,103 0,03 1,655 0,04 2,207 0,05 2,758 0,05 2,758

Pardoseala

parchet

30.50 0,04 1.22 0,04 1.22 0,06 1.83 0,08 2.44 0,08 2.44 0,1 3.05

Usa pvc 1.89 0.02 0.038 0.02 0.038 0.03 0.057 0.04 0.077 0.04 0.077 0.05 0.094

Fereastra 5.12 0.35 1.792 0.25 1.28 0.18 0.921 0.12 0.614 0.07 0.358 0.04 0.205

Dulap lemn 10.20 0.02 0.204 0.02 0.204 0.03 0.306 0.04 0.408 0.04 0.408 0.05 0.51

Draperie 11.52 0.06 0.691 0.27 3.11 0.44 5.07 0.5 5.76 0.4 4.61 0.35 4.032

Canapele

stofa

5.65 0.1 0.565 0.23 1.30 0.23 1.30 0.22 1.243 0.19 1.07 0.18 1.02

Masa lemn 0.84 0.02 0.017 0.02 0.017 0.03 0.025 0.04 0.035 0.04 0.035 0.05 0.042

Suprafata

plafon

30.50 0.02 0.61 0.02 0.61 0.03 0.915 0.04 1.22 0.05 1.525 0.05 1.525

Oameni 4 0.35 1.4 0.41 1.64 0.42 1.68 0.46 1.84 0.49 1.96 0.50 2

)*( Si

7.64 10.52 13.76 15.84 15.241 15.236

T=0.161*V/A

[s]

1.79 1.30 0.99 0.87 0.90 0.90

Izolarea la zgomot aerian a unui perete interior IA(EA)

1. Date generale Peretele are rol de perete despartitor living si livingul vecin si este alcatuit din beton celular autoclavizat de

25cm grosime, finisat cu tencuiala din mortar de var pe ambele fete.

Sperete=4.8*2.8 =13.44m2

2. Determinarea curbei indicilor de atenuare Rf Tab II 4/pag 102

a) Masa pe unitatea de suprafata m=0.04*1700+0.25*650=230.50kg/m

2

b) Frecventele fB si fC

fB=

=29.07 41Hz

fc=

=186.55 260Hz

RB=RC= 29dB

Frecv f Hz Valori ale indicelui de

atenuare R pe: Abateri ale curbei

Curba etalon

dB

Curba reala

calculata

Curba etalon

dB

Deplasata in

jos cu 11 dB

100 33 29 -4/2 +5/2

125 36 29 -7 +4

160 39 29 -10 +1

200 42 29 -13 -2

250 45 29 -16 -5

315 48 31 -17 -6

400 51 34 -17 -6

500 52 38 -14 -3

630 53 40 -13 -2

800 54 42 -12 -1

1000 55 44 -11 0

1250 56 47 -9 +2

1600 56 48 -8 +3

2000 56 51 -5 +6

2500 56 53 -3 +8

3150 56 55 -1 +10

158)( 25)( Vom avea: Tab II. 2 Pereti BCA 32(-20)

E A= - 11 dB

I A= E A +52 = -11+52 = 41dB .