Highway Materials

Question 1
The softening point of bitumen has the same unit as that of
A
distance
B
temperature
C
time
D
viscosity
GATE CE 2021 SET-2   Transportation Engineering
Question 1 Explanation: 
Softening point is the temperature at which bitumen becomes soft and starts flowing.
Question 2
Group-I gives a list of test methods for evaluating properties of aggregates. Group-II gives the list of properties to be evaluated.

The correct match of test methods under Group-I to properties under Group-II, is
A
P-4, Q-1, R-2, S-3
B
P-2, Q-1, R-4, S-3
C
P-3, Q-4, R-1, S-2
D
P-2, Q-4, R-3, S-1
GATE CE 2020 SET-2   Transportation Engineering
Question 2 Explanation: 
Soundness test is done to evaluate resistance against weathering of aggregate.
Crushing test is done to evaluate strength of aggregate.
Los angles abrasion test is to evaluate hardness of aggregate.
Stripping value test is to evaluate ratio of uncovered area observed to the total area of aggregate. The test is conducted to determine the effects of moisture upon the adhesion of binding material.
Question 3
The Los Angeles test for stone aggregates is used to examine
A
abrasion resistance
B
crushing strength
C
soundness
D
specific gravity
GATE CE 2020 SET-1   Transportation Engineering
Question 3 Explanation: 
Los Angles abrasion test is carried out to examine the hardness i.e., abrasion resistance property of aggregate
Question 4
Structural failures considered in the mechanistic method of bituminous pavement design are
A
Fatigue and Rutting
B
Fatigue and Shear
C
Rutting and Shear
D
Shear and Slippage
GATE CE 2019 SET-2   Transportation Engineering
Question 5
The initial concavity in the load-penetration curve of a CBR test is NOT due to
A
uneven top surface
B
high impact at start of loading
C
inclined penetration plunger
D
soft top layer of soaked soil
GATE CE 2018 SET-2   Transportation Engineering
Question 5 Explanation: 
Initial concavity in CBR test due to
Improper compaction.
Soft top layer
Inclined plunger
Question 6
A bitumen sample has been graded as VG30 as per IS : 73-2013. The '30' in the grade means that
A
penetration of bitumen at 25^{\circ}C is between 20 and 40
B
viscosity of bitumen at 60^{\circ}C is between 2400 and 3600 Poise
C
ductility of bitumen at 27^{\circ}C is more than 30 cm
D
elastic recovery of bitumen at 15^{\circ}C is more than 30%
GATE CE 2018 SET-1   Transportation Engineering
Question 7
The following observations are made while testing aggregate for its suitability in pavement construction:

i. Mass of oven-dry aggregate in air = 1000 g
ii. Mass of saturated surface-dry aggregate in air = 1025 g
iii. Mass of saturated surface-dry aggregate under water = 625 g

Based on the above observations, the correct statement is
A
bulk specific gravity of aggregate = 2.5 and water absorption = 2.5 %
B
bulk specific gravity of aggregate = 2.5 and water absorption = 2.4 %
C
apparent specific gravity of aggregate = 2.5 and water absorption = 2.5%
D
apparent specific gravity of aggregate = 2.5 and water absorption = 2.4 %
GATE CE 2017 SET-1   Transportation Engineering
Question 7 Explanation: 
Bulk specific gravity =\frac{A}{B-C}
Apparent specific gravity =\frac{A}{A-C}
Where,
A= Mass of oven dry aggregate in air
B= Mass of Saturated surface dry aggregate in air
C= Mass of Saturated surface dry aggregate under water
\therefore Bulk specific gravity
=\frac{1000}{1025-625}=\frac{1000}{400}=2.5
Water absorption
=\frac{1025-1000}{1000} \times 100=2.5 \%
Question 8
During a forensic investigation of pavement failure, an engineer reconstructed the graphs P, Q, R and S, using partial and damaged old reports.

Theoretically plausible correct graphs according to the 'Marshall mixture design output' are
A
P, Q, R
B
P, Q, S
C
Q, R, S
D
R, S, P
GATE CE 2016 SET-1   Transportation Engineering
Question 8 Explanation: 
The graph between VFB and Bitumen content is,

Question 9
In Marshall method of mix design, the coarse aggregate, fine aggregate, fines and bitumen having respective values of specific gravity 2.60, 2.70, 2.65 and 1.01, are mixed in the relative proportions (% by weight) of 55.0, 35.8, 3.7 and 5.5 respectively. The theoretical specific gravity of the mix and the effective specific gravity of the aggregates in the mix respectively are:
A
2.42 and 2.64
B
2.42 and 2.78
C
2.42 and 2.93
D
2.64 and 2.78
GATE CE 2015 SET-2   Transportation Engineering
Question 9 Explanation: 
Theoretical specific gravity,
\begin{aligned} G_{t} &=\frac{w_{1}+w_{2}+w_{3}+w_{4}}{\frac{w_{1}}{G_{1}}+\frac{W_{2}}{G_{2}}+\frac{W_{3}}{G_{3}}+\frac{W_{4}}{G_{b}}} \\ &=\frac{55+35.8+3.7+5.5}{\frac{55}{2.6}+\frac{35.8}{2.7}+\frac{3.7}{2.65}+\frac{5.5}{1.01}}+ \\ &=2.42 \end{aligned}
Effective specific gravity of aggregates (coarse + fine) is given by,
\begin{aligned} G^{\prime} &=\frac{(55 \times 2.6)+(35.8 \times 2.7)}{55+35.8} \\ &=2.639=2.64 \end{aligned}
Question 10
Match the information related to test on aggregates given in Group-I with that in Group-II.
A
P-1, Q-3, R-4, S-2
B
P-3, Q-1, R-4, S-2
C
P-4, Q-1, R-3, S-2
D
P-3, Q-4, R-2, S-1
GATE CE 2015 SET-2   Transportation Engineering
There are 10 questions to complete.

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