This paper reports on the progress of the development of recycled aggregate concrete (RA concrete) that is used in the production of a noise barrier for urban freeways. The following aspects of the development are covered: inherent strength and porosity of the recycled concrete aggregate (RC aggregate), the use of the aggregate in new RA concrete and an acoustic performance of the noise barriers made from this aggregate. The barrier under development utilises the porosity of the aggregate, which is further enhanced to produce a barrier, which absorbs sound energy in specific wavebands. Preliminary results based on laboratory scale prototype indicate sound absorption of up to 50 percent of incident sound waves striking the barrier in the low frequency band characteristic of traffic noise. (a)
Samenvatting