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In a bituminous pavement, alligator cracking is mainly due to

As per IRC:37-2012, in order to control subgrade rutting in flexible pavements, the parameter to be considered is

Consider the following statements:

P) RC-2 is thicker than MC-2 and SC-2.

Q) Emulsion are two phase systems consisting of two immiscible liquids and are used in patch repair works.

R) Bitumen and Tar are produced by the destructive distillation of wood.

Choose the correct code considering the above statements.

Match List – I (Pavement deficiency) with List-II (Explanation) and select the correct option.

List – I (Pavement deficiency)	List – II (Explanation)
Bird Baths	A steep-sided, bowl-shaped cavity caused by loss of surfacing as well as base course erosion.
Potholes	Deformations which may be caused by localized or variable subgrade failure.
Raveling	Removal of larger surface aggregate leaving craters.
Subsidence	Abrupt lowering of the road surface due to poor drainage.

A soil subgrade sample is analysed and the group index of the subgrade is found to be α. Result of the test analysis are listed as shown below:

(i) Liquid limit = 45%

(ii) Plastic limit = 25%

(iii) Soil passing 75 μ sieve = 60%

The thickness of the pavement is designed based on group index value and found to vary linearly with the group index. The thickness requirement from the standard data with Group Index is as tabulated below:

G.I. Values	Total thickness
0	20 cm
5	30 cm
10	40 cm
15	50 cm

 
The required pavement thickness based on above analysis is:

Plate bearing test was conducted on a 30 cm dia plate and yielded the following results:

Load (kg)	270	580	770	1010	1260	1480
Settlement (mm)	0.25	0.50	0.75	1.00	1.25	1.50

The modulus of subgrade reaction (k) in kg /m²/m corresponding to a 75 cm diameter plate

There is a 2-lane NH section as a divided highway. The existing traffic in one direction is 2500 commercial vehicles per day. The following design data is given for the modification of the highway:

Growth rate of traffic = 10%

VDF = 3.5, Design life = 10 years, Lane Distribution factor = 0.75

The construction of the pavement will take around 2 years for its completion. The cumulative standard axles at the end of design life is

The results of one day axle load survey on a road is as shown below:

Weight (kN)	Frequency (n)
0 – 50	50
50 – 100	150
100 – 150	200
150 - 200	50

If the total number of axles surveyed is 900 and the total number of vehicles is 450, the vehicle damage factor is (Consider the standard axle load is 80kN)

The tensile stress developed in the cement concrete pavement due to contraction is 0.5 kg/cm², the coefficient of friction between the bottom of the pavement and the supporting layer is 1.1 and the unit weight of cement concrete is 2400 kg/m³. Calculate the spacing between the contraction joint (in meters).

Cohesiometer value (c) for the three layered pavement section respectively is given below.

Materials	Thickness (cm)	C-value
Bituminous concrete	11.5 cm	70
Cement treated base	23 cm	260
Gravel sub-base	18 cm	30

 

The equivalent c-value of the three layered pavement section will be ________.