Abstract
It is necessary to estimate acoustic decline caused by rot to maintain wood sound barriers for the long term. We tried to estimate the life of the wood sound barriers by conducting a fungus cellar test to perform accelerated deterioration of small specimens with specifications equivalent to real wood sound barriers as well as measuring sound transmission losses using a small anechoic box. The sound transmission losses of untreated specimens were all less than the standard value provided by the sound barrier regulation for Japanese expressways 24 months after the accelerated deterioration test started. Conversely, the sound transmission losses of specimens treated with preservatives still exceeded the standard value mentioned above 42 months after the test started. Because the rate of deterioration of wood specimens in the fungus cellar test is considered about 6 times that in an outdoor condition, the service life of preservative-treated wood sound barriers can be estimated as at least 20 years.
