Test: Highway Materials & Testing- 1

Petrol is not used directly in highway construction, but by-product like bitumen is used. Stone, dust and soil may be used in subgrade and base.

If the HFL is more than the formation level of the road which is going to be provided, then it has to be built on embankment.

The embankment is the lowest layer and it is below the sub grade, base is above sub base, sub base is above the sub grade.

CBR number decreases with an increase in height, the soil requires the highest CBR and the pavement requires the lowest CBR.

Fly ash is an industrial waste obtained from the thermal plants, it has been mandatory to use the fly ash in bricks.

Bitumen is obtained by burning the petroleum at high temperatures, it is mostly used in the construction of flexible pavements.

It is a natural substance, oozing out of the ground in places like the La Brea tar pits. Usually it is made by heating coal inside a chemical apparatus. Most tar is produced from coal as a byproduct of coke production, but it can also be produced from petroleum, peat or wood.

Flexible pavements are easy to construct and have cheaper cost than C. C pavements and also they are easily accessible to the users.

For the bituminous concrete surface course, the impact value should not exceed 24%, so the sample in the question cannot be used. For cement concrete base course, it must not exceed 45%, bitumen bound macadam base course 35% and for water bound macadam base course 40%.

The length of gauge size is obtained by multiplying the average of sieve sets with 1.8. So, for particles passing 25 mm sieve and retained on 20 mm sieve, the length of the gauge size would be