Highway Materials (bituminous)
This article is about highway and transport engineering, this time we talk about the Highway Materials (aggregates)
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Bituminous materials are used extensively for roadway construction, primarily because of their excellent binding or cementing power and their waterproofing properties, as well as their relatively low cost. Bituminous materials consists primarily of bitumen, which, according to ASTM D8, is a class of black or dark colored solid or viscous cementitious subsatnces composed chiefly of high molecular weight hydrocarbons; by definition, it is soluble in carbon.
Bituminous materials are divided into two broad categories: asphalt and tars. Asphalts are the residues of the petroleum oils. A great majority of asphalts used nowadays are the residues from the refinery of crude oils, although there are natural deposits called "native asphalt." Tars are residues from the destructive distillation of organic substances such as coal, wood or petroleum. Tars obtained from the destructive distillation are tars, which must undergo further refinement to become road tars.
Asphalts have no odor, are more resistant to weathering, and less susceptible to temperature than tars, which have a pungent (creosote like) odor and react to weathering and temperature. Asphalt will be dissolved in petroleum oils whereas tars will not. Therefore, tars have been used to seat asphalt concrete surfaces, such as fog seals, to improve the oil resistance of asphalt surfaces. Asphalt are lack in color, whereas tars are usually brown black in color.
Today, tars are not used extensively as binders for highway pavements, and therefore, they are treated only lightly here.
(source: Wright, P.H, with contributions by James S. Lai, Peter S.Parsonson, Michael Meyer., Highway Engineering, 6th edition ,John Wiley & Sons, Inc.New York, 1996.)
.jpg)
pict source : www.lmsqld.com.au
.jpg)
pict source : www.ecvv.com
Bituminous materials are used extensively for roadway construction, primarily because of their excellent binding or cementing power and their waterproofing properties, as well as their relatively low cost. Bituminous materials consists primarily of bitumen, which, according to ASTM D8, is a class of black or dark colored solid or viscous cementitious subsatnces composed chiefly of high molecular weight hydrocarbons; by definition, it is soluble in carbon.
Bituminous materials are divided into two broad categories: asphalt and tars. Asphalts are the residues of the petroleum oils. A great majority of asphalts used nowadays are the residues from the refinery of crude oils, although there are natural deposits called "native asphalt." Tars are residues from the destructive distillation of organic substances such as coal, wood or petroleum. Tars obtained from the destructive distillation are tars, which must undergo further refinement to become road tars.
Asphalts have no odor, are more resistant to weathering, and less susceptible to temperature than tars, which have a pungent (creosote like) odor and react to weathering and temperature. Asphalt will be dissolved in petroleum oils whereas tars will not. Therefore, tars have been used to seat asphalt concrete surfaces, such as fog seals, to improve the oil resistance of asphalt surfaces. Asphalt are lack in color, whereas tars are usually brown black in color.
Today, tars are not used extensively as binders for highway pavements, and therefore, they are treated only lightly here.
(source: Wright, P.H, with contributions by James S. Lai, Peter S.Parsonson, Michael Meyer., Highway Engineering, 6th edition ,John Wiley & Sons, Inc.New York, 1996.)
Title Post: Highway Materials (bituminous)
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Author: aditya
Rating: 100% based on 99998 ratings. 5 user reviews.
Author: aditya
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