AGGREGATES AND VARIOUS BINDERS AND ADDITIVES

paper presents part of an on-going research effort to develop alternative asphalt surface mixtures that are quieter and durable without much sacrifice of safety. The objective of the study is to investigate the effects of several common combinations of binder type and additive on noise reduction property and durability of a small aggregate size, open-graded (porous) asphalt mixture. Five binder types (PG 64-16, PG 58-34PM, PG 76-22PM, asphalt rubber, and PG 76-22TR) and two additives (hydrated lime and cellulose fiber) were selected for a 4.75-mm nominal maximum aggregate size (NMAS) gradation and a series of laboratory tests were conducted to evaluate their pavement surface performance related properties, including acoustic absorption, texture, resistance to raveling, moisture sensitivity, permeability, friction, resistance to permanent deformation, and resistance to reflective cracking. Results show that using polymer-modified or rubberized binders instead of unmodified binder in the 4.75-mm NMAS open-graded mixture reduces permeability, but increases acoustic absorption, with the mixture containing asphalt rubber binder showing the most acoustic absorption improvement. Using asphalt rubber can also increase the mixture resistance to moisture damage/premature failure, raveling, rutting, an