HP Bitumen Handbook - Hindustan Petroleum Corporation Limited

Appendix-I : road metals and
materials
SATURATES: Saturates are aliphatic hydrocarbons and are non polar in nature.
They are white or straw in colour. Saturates account for 5 to 20% of the weight of
bitumen. Increasing Saturates can make the bitumen softer.
SHOULDER - In highway use, that portion of the roadbed between the traveled
way or pavement and the top of the ditch slope in cuts or top of embankment in
fills.
SILT - Silt consists of natural mineral grains smaller than 0.05 mm which lack
plasticity and have little or no dry strength.
SLAG - Fused or partially fused composed of silica in combination with lime or
other bases, resulting in secondary products from the reduction of metallic ores.
SLAKED LIME - Slaked lime is calcium hydroxide, a compound formed by
hydration of free lime.
SOFTENING POINT : Softening point is the temperature at which a standard
quantity of bitumen will become fluid. It is usually tested by a ball/ring test
method.
SOLUBILITY :
The portion of bitumen which fully dissolves in carbon
tetrachloride represents the actual binder material in the bitumen sample.
TALUS - Talus is naturally broken stone as is often found in slides and at the
base of rocky heights. Talus rock, with some exceptions, has all faces fractured
and is usually classified angular to subangular.
TAR: Tar is obtained during the process of destructive distillation of wood or
coal. Tar was used in road construction in India till 1950s. Today due to better
quality and availability Bitumen has completely replaced tar in the road
construction industry.
THEORETICALLY GRADED STONE : Theoretically graded stone is obtained by
uniformly mixing calculated percentages of known graded sizes to yield a
combined gradation suited to the work proposed. Gradation limits are ordinarily
specified in writing or are shown on a gradation chart, in either case the
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