Transportation Engineering (General Engineering) (SSC JE)

• Hardness of bitumen is obtained by the penetration test, it measures the distance a standard blunt pointed needle will vertically penetrate a sample of materials at 25ºC, the load being 100 g and time of application of load being 5 seconds.
• The unit of penetration is 1/10 nm. Thus 80/100 grade bitumen mean 8-10 mm penetration.
• Penetration test on bitumen is used for determining its grade.

Bituminous emulsion–It is a condition in which bitumen is suspended is an aqueous medium. It is used for patch up work. The biggest advantage of bitumen emulsion is that it can be used in rainy season also.
• Cut back bitumen is a type of bitumen which is obtained when viscosity of bitumen is reduced by volatile diluent. It is generally used in colder regions.

The surface roughness on a drawing is represented by triangles. These are classified into four groups

As per Indian Road Congress, the slope of earth in cutting should be 1 : 1, and for filling this ratio takes 2 : 1.

Aggregate impact value test gives an indication of aggregate's toughness property.
• Aggregate to be used for wearing course, the impact value shouldn't exceed 30%.
• Bituminous macadam, the maximum permissible value is 35%.
• Water bound macadam base courses the maximum permissible value defined by IRC is 40%.
• To provide large openings in the existing walls such as doors, windows, shop fronts or garages at a lower level.

Bitumen–Bitumen is a petroleum based material used for binding stone and sands and producing asphalt for road construction.