Geometric Design (Parameters) of HILL ROAD

Design of Hill Road  to predetermined standard is necessary so that  travel is safe and comfortable.

Class 9 : Other District Road

Class 5 : Village Road

Road Land Width (Right of way): It is the land width required for Road Purpose.

Carriage Way : It is the portion of Roadway designed & constructed for vehicular traffic.

Roadway : It is sum of carriageway width and shoulder width on either side.It is exclusive of side drain & parapets.

Formation Width: It is Roadway width + side drain + parapets.

Shoulder: It is the portion immediately beyond the edges of carriageway on which vehicular traffic may pass occasionally.

AS PER LATEST IRC: THERE IS NO SINGLE LANE ROAD.

-Roadway width is exclusive of side drain width (usually 0.6m) & parapet width (usually 0.6m).
- In case Retaining wall with parapet is provided on valley side then earthen shoulder may not be provided.
-Strategic and Border Road for Military purpose shall be constructed for not less than two lane carriageway along with paved shoulder on Hill side + paved and earthen shoulder on valley side.
-In  hard Rock, width may be reduced by 0.8m for two lane road.


AS  PER IRC :52 -1981

AS PER BRO TI-1

In BRO TI , It is Roadway width + side drain + parapets.(side drain =0.6m & parapet =0.6m)

Camber : Camber is a slope given to the cross section of the carriage way.

Design Speed : 

Sight Distance: It is the distance along the road surface at which driver has visibility of object at a specified height above the carriageway.

Minimum Radii of Horizontal Curve :

Vertical Alignment : Recommended Gradients

Passing Place on single Road:

Bridle Road , Bridle parth and OP Track : Isolated village habitation can be connected by bridle road or bridle path.(for the pocket of very small population in remote areas)

All about Bitumen (Type, Requirements, Selection, Tests & Conformity Criteria)

Bitumen is prepared by the refining of crude petroleum by suitable methods.

In the third revision of IS:73-2006 grading of bitumen was changed from penetration grade to viscosity grade.

Grades of Bitumen & Selection of Bitumen:
Bitumen is classified into four grades based on the viscosity, and suitability recommended for maximum air temperature as given below:

Latest revision has also rationalized the Bitumen selection process by categorizing the binder grade based on design maximum air temperature.
So,The choice of the grade depends upon the design maximum air temperature of the location where the binder has to be used.

Requirements of Bitumen : 
The various grades of bitumen shall conform to the requirements prescribed below:

In  latest revision (2013), emphasis is given to the viscosity measurement at 60°C & hence viscosity ranges are provided for all the grades instead of a range for penetration as specified in the third revision(2006). Rather,Minimum value of penetration at 25°C is stipulated.

Tests on Bitumens: 
Tests on Bitumen are given above in table for requirements for bitumen.

Adoption of viscosity-graded paving bitumen specification also reduced the number of total tests to seven, resulting in reduced cost of testing paving bitumen.

Ductility test is no longer mandatory for specification compliance.

This eliminated empirical tests/parameters such as, penetration ratio, paraffin wax content, and Fraass breaking point without compromising the quality of bitumen.

No. of Samples for Test : The number of containers to be selected at random from the lot shall depend upon the size of the lot given  below:

Criteria for Conformity : The lot shall be considered as conforming to the requirements of bitumen, if the condition mentioned  below is satisfied.

Condition: From the test results of absolute viscosity at 60°C,penetration and softening point, the mean ( X ) and the range (R) shall be calculated. The following conditions shall be satisfied:

a) [ x –0.6R] shall be greater than or equal to the minimum specification limit specified in Table for requirements of bitumen and
b) [ x + 0.6R] shall be less than or equal to the maximum specification limit specified in Table for requirements of bitumen.

-BRO TI 25 may be read with this latest revision of bitumen.