Determination of the sound reduction and sound absorption of a railroad noise barrier

Transcription

1 TEST REPORT No. VTT-S October 29, 2014 Determination of the sound reduction and sound absorption of a railroad noise barrier Requested by: Soundim Oy

2 TEST REPORT No. VTT-S (3) Requested by Order Contact person Soundim Oy Pakkaskuja Vantaa by Jukka Näräkkä / confirmation of order VTT-O VTT Expert Services Ltd Veijo Sivonen P.O. Box 1001, FI VTT, Finland Tel , Fax veijo.sionen@vtt.fi Task Determination of the airborne sound insulation and sound absorption of railroad noise barrier Structure of the Photos of the measurements and the structure and details of the noise barrier specimen are show in Appendix 2. Date and place of testing Installation and measuring The sound insulation of the noise barrier was tested and sound absorption was tested by the personnel of VTT Expert Services Ltd at VTT Expert Services Ltd:s research hall 1. The airborne sound insulation test specimen was installed by VTT Expert Services Ltd:s personnel into the measurement opening (with dimensions 1210 x 1030 mm) between two reverberation rooms. The sound absorption test specimen (with size 3 m x 4 m) was installed client onto the floor of a reverberation room KH 3. The airborne sound reduction index of the specimen was determined by means of two-channel sound pressure level measurement with two fixed sources and moving microphones. The measurement we carried out by Technical Expert Veijo Sivonen. Method and equipment The sound reduction index R was measured in accordance with EN ISO : in one third octave bands and the single number rating DL R and categorisation was determined in accordance with EN and EN and 3. Sound insulation of the barrier was measured specimen area, which was smaller than that 12 m 2 provided by the standard. It can be approximated that the sound reduction index of the smaller specimen is a baud 2 db higher than that of specimen with area of 12 m2. However, this has no effect on the achieved classification.

3 TEST REPORT No. VTT-S (3) Sound absorption and sound absorption coefficients Si in one third octave bands were measured according to standard EN The single number rating DL and categorisation was determined in accordance with EN Reverberation room dimensions and measuring equipment are presented in Appendix 3. Results The individual measuring result are presented in Appendix 1. The categorisation of the railroad noise barrier is as follows: Noise barrier Aluminium frame / insulation (Evona 36 kg/m 2 ) / metal cladding Sound insulation Sound absorption DL R db(a) Category DL α Category 30 B3 13 A4 Espoo October 29, 2014 Pekka Sipari Senior Expert Veijo Sivonen Technical Expert VTT Expert Services Ltd. is notified body No. NB FINAS Finnish Accreditation Service has accredited our laboratory (T001, VTT Expert Services Ltd) to perform the tests mentioned.

4 TEST REPORT No. VTT-S (3) Appendices Appendix 1 Results Appendix 2 Structure of the noise barrier and photos from measurements Appendix 3 Reverberation rooms and equipments Distribution Customer Original Archive Original References [1] EN ISO :2010 Acoustics - Measurement of sound insulation in buildings and of building elements - Part 2: Laboratory measurements of airborne sound insulation of building elements 2 EN Road traffic noise reducing devices. Test method for determining the acoustic performance. Intrinsic characteristics of airborne sound insulation 3 EN Road traffic noise reducing devices. Test method for determining the acoustic performance. Normalized traffic noise spectrum 4 EN ISO 354 Acoustics - Measurement of sound absorption in a reverberation room 5 EN Road traffic noise reducing devices. Test method for determining the acoustic performance. Intrinsic characteristics of sound absorption

5 Sound reduction index, R, db TEST REPORT No. VTT-S APPENDIX 1 1 (2) Results sound insulation Client: Soundim Oy Product identification: Railroad noise barrier Vantaa Aluminium frame / insulation (Evona 36 kg/m2) / metal cladd Test specimen mounted by: VTT Expert services Oy Date of test: Areas of test specimen: 1,3 m² Air temp. in the test rooms: 21 C Air humidity in the test rooms: 46 % Source room volume: 102 m³ Receiving room volume: 131 m³ Frequency range acording to the curve of reference values ISO Frequency One-third f octave Hz db 50 20, , , , , , , , , , , , , , , , , , , , , Frequency f, Hz Rating according to ISO 717-1: According to EN and EN1793-3: R w (C ;C tr ) = 36 (-2 ; -6) db; DL R = 30 db(a) CATEGORY: B3 Evaluation based on laboratory measurement results obtained by an engineering method

6 Absorption coefficient s (ISO 354:1985) TEST REPORT No. VTT-S APPENDIX 1 2 (2) Determination and classification of sound absorption Customer: Soundim Oy Pakkaskuja 1, Vantaa Reverberation room: Order: Jukka Näräkkä Volume : 201 m 3 Surf. area: 209 m 2 Test site: VTT/TH1 Otaniemi Sample: 12,1 m 2 Date of test: Temperature and relative humitidy: Commission: Determination and classification of absorption coefficient Empty 21 C 59 % (ISO , E and EN :1998) Sample 21 C 59 % Specimen: Area: Mass: Installation: Railroad noise barrier: aluminium frame / insulation (Evona 36 kg/m2) / metal cladding 12,1,8 m2 60 kg/m2 Sample on the floor RESULTS: 1,2 1 0,8 0,6 0,4 0, Frequency (Hz) Freq. T 1 T 2 S (Hz) (s) (s) 100 4,86 2,27 0, ,21 2,47 0, ,43 2,12 0, ,10 1,95 0, ,25 1,90 0, ,06 1,93 0, ,37 1,80 0, ,46 1,74 0, ,79 1,73 0, ,02 1,73 1, ,04 1,77 0, ,73 1,74 0, ,23 1,66 0, ,83 1,59 0, ,51 1,53 0, ,03 1,49 0, ,57 1,42 0, ,15 1,31 0,80 DL = 13 Class A4

7 TEST REPORT No. VTT-S APPENDIX 2 1 (3) Structure of the noise barrier and photos from measurement

8 TEST REPORT No. VTT-S APPENDIX 2 2 (3)

9 TEST REPORT No. VTT-S APPENDIX 2 3 (3) Photo 1. Airborne sound measurement Photo 2. Absorption measurement

10 TEST REPORT No. VTT-S APPENDIX 3 1 (1) Measuring equipment and reverberation room dimensions / Sound insulation Measuring equipment Name Serial No. Condenser microphone B&K (Brüel&Kjær) Condenser microphone B&K (Brüel&Kjær) Microphone preamplifier B&K Microphone preamplifier B&K Rotating microphone boom B&K Rotating microphone boom B&K Power amplifier Yamaha MX-1000 Loudspeakers Sinmarc V121L Real-time analyser Norsonic Sound calibrator B&K Reveberation room dimensions Floor Height Volume Source room KH1 4.7 m x 5.8 m 3.7 m 102 m 3 Receving room KH2 5.0 m x 6.5 m 4.0 m 131 m 3 Thickness of the concrete walls, floors and ceilings of the reverberation rooms is 0.25 m Measuring equipment and reverberation room dimensions / Sound absorption Measuring equipment Name Serial No. Condenser microphone B&K (Brüel&Kjær) Microphone preamplifier B&K Rotating microphone boom B&K Power amplifier Peavey PV 2600 Loudspeakers Sinmarc V121L Real-time analyser Norsonic Sound calibrator B&K Reveberation room dimensions Floor Height Volume Reveberation room KH m x 7.20 m 4.70 m 201 m³ Thickness of the concrete walls, floors and ceilings of the reverberation rooms is 0.25 m