%0 Journal Article
%T 30 Years of Microsurfacing: A Review
%A Ben Broughton
%A Soon-Jae Lee
%A Yoo-Jae Kim
%J ISRN Civil Engineering
%D 2012
%R 10.5402/2012/279643
%X Microsurfacing has been utilized in the United States since 1980 as a maintenance treatment for pavement. This paper reviews the benefits, limitations, and factors that contribute to successful applications of microsurfacing. The history of microsurfacing, as well as a definition and process description of the treatment, is included. The body of scientific work on microsurfacing is shown to promote its use in preventative maintenance programs, and the potential for microsurfacing to meet tightening environmental and budgetary restrictions is discussed. Suggestions are given for future research to expand microsurfacing¡¯s applications and efficacy stemming from the ability of microsurfacing to be cold-applied and utilize polymers in the bitumen. 1. Introduction Microsurfacing is a road maintenance tool that involves laying a mixture of dense-graded aggregate, asphalt emulsion (about 7% by weight), water, polymer additive (about 3% by weight), and mineral fillers (about 1% of weight of total dry mix) to correct or prevent certain deficiencies in pavement conditions [1]. In the same category of pavement treatments as seal coating and thin hot mix asphalt (HMA) overlays, microsurfacing treatments cover the entire width of the roadway to which they are applied [2]. The treatment may be as thin as 3/8 inch (9.5£¿mm), or it can fill wheel ruts up to 2 inches (50.8£¿mm) deep using multiple passes. Because of the similar ingredients used in microsurfacing as in slurry seals, microsurfacing is sometimes referred to as a ¡°polymer-modified slurry seal.¡± The difference, however, is slurry seals cure through a thermal process while microsurfacing uses a chemically controlled curing process [3]. Since the use of a polymer-modified binder results in more stability, microsurfacing can be placed in multistone thicknesses, unlike slurry seals. Due to this thickness, more powerful mixers are needed than those required for slurry seals. In order to provide a uniform flow of the mixture into the spreader box, a twin-shafted paddle or spiral auger is needed [4]. Microsurfacing should not be applied if either the pavement or air temperature is below 50¡ãF (10¡ãC) nor if there is a possibility of the treatment freezing within 24 hours of placement [3]. Microsurfacing is generally classified as a preventative maintenance treatment as opposed to a corrective maintenance treatment [5]. Due to this classification by agencies involved in road repair and maintenance, microsurfacing is most often used as a surface treatment to correct rutting, improve surface friction, and extend pavement
%U http://www.hindawi.com/journals/isrn.civil.engineering/2012/279643/