Hempcrete Noise Barrier Wall for Highway Noise Insulation : Research & Construction
KC, Prabesh (2016)
Hämeen ammattikorkeakoulu
2016
All rights reserved
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2016122121327
https://urn.fi/URN:NBN:fi:amk-2016122121327
Tiivistelmä
The purpose of this thesis was to study the possibility of Hempcrete or hemp-lime composite noise barrier walls in the highways and to construct the walls for the acoustic test according to the European Union Standards EN ISO 717-1 and ISO 10140-2 for air-borne sound insulation. The thesis was commissioned by the company Hemprefine Oy, and all the standard tests were performed in the HAMK-Ruukki Sheet Metal Centre in Hämeenlinna and the VTT Technical Research Centre of Finland Ltd in Espoo.
Three Hempcrete walls were constructed in the HAMK –Ruukki Sheet Metal center with different mixing proportions of hemp shives, lime and water. Wall 1 was cast with only small shives in the mix, wall 2 was cast with only large shives in the mix, and wall 3 was cast in a state of the art design after the careful study of the acoustic behavior across Hempcrete walls.
The acoustic measurements in one-third octave bands showed varying insulating responses among three different walls. Wall 1 and 2 produced unsatisfactory results with a Sound Reduction Index, Rw of less than 20 decibels and were unable to meet the acoustic standards. However, wall 3 constructed in a state of the art design performed much better with a Rw of 46 decibels. The results showed that a specific structure of Hempcrete wall can provide a Sound Reduction Index of the wall which meets the European and the Finnish standards. In addition, the water-proof, rot-proof and the moisture-proof properties of the Hempcrete noise barrier wall along with its capacity to store carbon dioxide in its molecular fabric, make it an environmentally sustainable construction solution in the future. To maintain confidentiality and copy rights of the successful invention of the thesis work commissioned by Hemprefine Oy, the design and casting methods of Hempcrete wall- 3 have not been described within this publication.
Three Hempcrete walls were constructed in the HAMK –Ruukki Sheet Metal center with different mixing proportions of hemp shives, lime and water. Wall 1 was cast with only small shives in the mix, wall 2 was cast with only large shives in the mix, and wall 3 was cast in a state of the art design after the careful study of the acoustic behavior across Hempcrete walls.
The acoustic measurements in one-third octave bands showed varying insulating responses among three different walls. Wall 1 and 2 produced unsatisfactory results with a Sound Reduction Index, Rw of less than 20 decibels and were unable to meet the acoustic standards. However, wall 3 constructed in a state of the art design performed much better with a Rw of 46 decibels. The results showed that a specific structure of Hempcrete wall can provide a Sound Reduction Index of the wall which meets the European and the Finnish standards. In addition, the water-proof, rot-proof and the moisture-proof properties of the Hempcrete noise barrier wall along with its capacity to store carbon dioxide in its molecular fabric, make it an environmentally sustainable construction solution in the future. To maintain confidentiality and copy rights of the successful invention of the thesis work commissioned by Hemprefine Oy, the design and casting methods of Hempcrete wall- 3 have not been described within this publication.