Stone Mastic Asphalt PDF Print E-mail
Written by Carl Thodesen   
Stone Mastic Asphalt (SMA) was initially developed in Europe to minimize the effects of studded tires on pavements. Since its introduction to the USA, it has primarily been used for its resistance to permanent deformation, noise reduction, and for its increased durability. 

SMA is composed of crushed coarse aggregate, crushed fine aggregate, mineral filler, asphalt cement, and a stabilizing agent. One of the main design requirements for an SMA mix design is the resistance to draindown of the binder. Research confirms that draindown can be prevented through the use of fibers and/or polymers. Studies have shown that asphalt rubber can be used without additional fibers to achieve the draindown requirements of SMA pavements. Additionally, the increased elasticity of asphalt rubber also prevents the formation of thermal cracking in SMA pavements.


As illustrated in the figure below, SMA blends utilize high coarse aggregate contents (70-80%) and high asphalt contents (usually over 6%). The purpose of the high coarse aggregate content is to promote stone on stone contact which in turns yields a more rut resistant pavement.










ECOPATH has extensive experience in suggesting the right pavement types to certain climatic zones/countries, moreover ECOPATH is dedicated to developing solutions with economic efficiency as a priority. Please contact us for further information on mix and binder design services. 
Last Updated ( Tuesday, 30 June 2009 22:36 )