Preliminary Investigation of Acoustical Properties of Concrete Containing Oil Palm Shell as an Aggregate ReplacementJ. Zanariah, H. Zaiton, Y. Musli Nizam, Y. Khairulzan, M. Dianah, D. Nadirah and O. Mohd HanifiE3S Web Conf., 34 (2018) 01015DOI: https://doi.org/10.1051/e3sconf/20183401015