多孔磨耗层外文翻译.doc

Characterization of porous friction course mixes for different Marshall compaction efforts Department of Cvili Engnieernig,Natoina lInsttiute of Technology Karnataka,Surathka,lMangaolre 575 025,India ABSTRACT Porous friction courses(PFCs)are mainly recommended as surface drainage layers on high-speed roadcorridors and runway pavements.Permeability and sound attenuation characteristics are considered to bet he indicesf orp erformancea ssessmento fP FCs.Oneo ft her easonsf or thel osso fp ermeabilityi nP FCs is densification under heavy traffic.But,resistance to ravelling too,is of main concern in the case of under-compacted PFCs.This paper summarises the details of laboratory investigation on the characterization of PFC mixes corresponding to four different gradations and two binder contents,for three levels of the Marshallc ompaction.Thef indings oft he investigations uggestt hat thes electiono ft hec ompaction level for PFC mix design should be based on the design traffic level,and the gradation selected. 2009 Elsevier Ltd.All rights reserved. Keywords: Porous friction course Porous asphalt Marshall compaction Air voids Voids in coarse aggregate Permeability Moisture susceptibility Abrasion loss Introduction Porous friction courses(PFCs)are typical open-graded asphaltic mixes,composed of relatively uniformly-graded aggregate and asphalt cement or modified binders,and are mainly used to serve as drainage layers,either at the pavement surface or within the pavement structure[1].Pavements surfaced with open-graded asphaltic mixes were found to improve wet weather skid-resistance,minimize hydroplaning,reduce splash and spray,improve night visibility during wet weather conditions,and reduce traffic tyrenoise[2,3].In countries like the United States of America,Japan,the United Kingdom,Malaysia,Australia,New Zealand,and South Africa,open-graded mixes are in use as surface layers over high-speed and heavily trafficked highway pavements[2–8].These are also