Basic knowledge for a highway Engineer || Interview questions for a road construction job

This video is about basic knowledge for a highway engineer. In this video we discussed top 10 interview questions for a site Engineer highway.This video is helpful for civil engineers, fresher civil engineers, highway engineers, transportation engineers and civil engineering students.
HI !
Today, we are going to discuss some basic knowledge which a highway engineer must know.
1-Do you know about types of roads?
Roads are classified as flexible payments and Rigid payment.
2- what is structure of flexible payment?
Flexible payment has 4 main layers
1-subgrad
2-subbase
3-base
4-Asphaltic course
3-What is wearing course?
Wearing course is the top asphaltic course used for providing comfortable drive.
4-What is CBR?
CBR is termed as "California bearing ratio" .It is a measure of the strength of the subgrade of a road or other paved area, and of the materials used in its construction.
5-what is minimum CBR value for subgrade according to NHA ?
According to NHA specifications, for top 30 cm ,CBR shall not be less than 8 % .
6-What is Optimum Moisture Content?
During compaction of soil when compacting effort is applied, grains of soil slip, break and rearrange
themselves. Some lubrication is required to ease this phenomenon and for that water is used. So, the
max value of water or moisture at which maximum dry density achieves, is called optimum moisture
content.
7-How the compaction quality be controlled in the field?
Core cutter (Direct in-situ)
 Sand Cone ( Direct in - situ)
 Water Balloon ( Direct in-situ)
 Nuclear Densometer ( Indirect in-situ)
8-What is PGL?
The profile grade line (PGL) is a longitudinal section taken along the centerline and shows the
elevations to which road is built.
9-What types of soil are well suitable for subgrade?
A-1-a, A-1-b, A-2-4, according to AASHTO soil classification.
10-What is the proctor test?
The Procter Compaction Test is a laboratory method of (experimentally) determining the optimum
moisture content at which a given soil becomes most dense.