21. The minimum value of CBR(%) required for granular sub base as per Ministry of Surface Transport (MOST) specification is
    

1. 1. 5
      

   
   
   

   2. 10
      

   
   
   

   3. 15
      

   
   
   

   4. 20

   
   
   

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1. View Hint View Answer Discuss in Forum

   As per MOST standard, minimum value of CBR (% required for granular sub-base is 5%).
   

   Correct Option: A

   As per MOST standard, minimum value of CBR (% required for granular sub-base is 5%).
   

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22. A Marshall specimen is prepared for bituminous concrete with a bitumen content of 5 percent by measured unit weights of the mix are 2.442 g/cm³ and 2.345 g/cm³ , respectively. The bitumen has a specific gravity of 1.02. The percent voids in mineral aggregate filled with bitumen (VFB) are
    

1. 1. 34.55
      

   
   
   

   2. 35.9

   
   
   

   3. 73.55
      

   
   
   

   4. 74.3

   
   
   

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1. View Hint View Answer Discuss in Forum

   G_t = 2.442 g/cm²
   Gm = 2.345 g/cm²
   

   % air voids (Va) =	Vol. of air	= 1.917
   	Total volume

   
   

   =		Gt - G		× 100
   		C1

   
   

   =	2.442 - 2.35	× 100 = 4.1369
   	2.345

   
   

   Vol of bitumen ,Vb = Gm ×	Wb
   	Gb

   
   

   =	2.345 × 0.05	= 11.49%
   	1.02

   
   % voids filled by bitumen
   

   =	0.11495	= 73.536%
   	0.11495 + 0.04

   
   

   Correct Option: C

   G_t = 2.442 g/cm²
   Gm = 2.345 g/cm²
   

   % air voids (Va) =	Vol. of air	= 1.917
   	Total volume

   
   

   =		Gt - G		× 100
   		C1

   
   

   =	2.442 - 2.35	× 100 = 4.1369
   	2.345

   
   

   Vol of bitumen ,Vb = Gm ×	Wb
   	Gb

   
   

   =	2.345 × 0.05	= 11.49%
   	1.02

   
   % voids filled by bitumen
   

   =	0.11495	= 73.536%
   	0.11495 + 0.04

   
   

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23. Three new road P, Q and R are planned in a district. The data for these roads are given in the table below.
    
    Based on the principle of maximum utility, the order of priority for these three roads should be
    

1. 1. P,Q,R
      

   
   
   

   2. Q,R,P
      

   
   
   

   3. R,P,Q
      

   
   
   

   4. R,Q,P

   
   
   

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1. View Hint View Answer Discuss in Forum

   Based an population, weightage is
   < 2000: 1
   2000 – 5000 : 2
   75000 : 3
   

   P =	(8 × 1) + (6 × 2) + (1 × 3)	= 1.15
   	20

   
   

   Q =	(19 × 1) + (8 × 2) + (4 × 3)	= 1.68
   	28

   
   

   R =	(7 × 1) + (5 × 2) + (2 × 3)	= 1.917
   	12

   
   ∴ R > Q > P
   

   Correct Option: D

   Based an population, weightage is
   < 2000: 1
   2000 – 5000 : 2
   75000 : 3
   

   P =	(8 × 1) + (6 × 2) + (1 × 3)	= 1.15
   	20

   
   

   Q =	(19 × 1) + (8 × 2) + (4 × 3)	= 1.68
   	28

   
   

   R =	(7 × 1) + (5 × 2) + (2 × 3)	= 1.917
   	12

   
   ∴ R > Q > P
   

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24. For a road with camber of 3% and the design speed of 80 km/hr, the minimum radius of the curve, beyond which NO superelevation is needed, is
    

1. 1. 1080 m
      

   
   
   

   2. 948 m
      

   
   
   

   3. 406 m
      

   
   
   

   4. 280 m

   
   
   

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1. View Hint View Answer Discuss in Forum

   e + f =	(0.75V)2
   	127R

   
   

   0.03 =	(0.75 × 80)2
   	127 × R

   
   ∴ R = 9 uum

   Correct Option: B

   e + f =	(0.75V)2
   	127R

   
   

   0.03 =	(0.75 × 80)2
   	127 × R

   
   ∴ R = 9 uum

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25. In the context of flexible pavement design, the ratio of contact pressure to tyre pressure is called the Rigidity Factor. This factor is less than unity when the tyre pressure is
    

1. 1. less than 0.56 N/mm²
      

   
   
   

   2. equal to 0.56 N/mm²
      

   
   
   

   3. equal to 0.7 N/mm²
      

   
   
   

   4. more than 0.7 M/mm²

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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