Bituminous Mix Design - IES Previous Year Questions

1. A typical Marshall test graph is shown in the given figure. The variable on the X-axis is % binder content by weight of total mix. The variable on the Y-axis for the given graph will be _____ .

[IES 1995]

  1. Flow value
  2. Percentage of voids
  3. Unit weight
  4. Stability value
Answer: Option A
Explanation:
As the percentage of bitumen content increases, the flow value of the mix also increases, but the graph is concave upwards.

2.  Which one of the following diagrams illustrates the relationship between VMA and % bitumen content (BT) in Marshall test ?

[IES 1996]

Answer: Option D
Explanation:
  • Curve (A) represents the percentage of air voids in the total mix with respect to bitumen content.
  • Curve (B) represents the flow value of the mix with respect to bitumen content.
  • Curve (C) represents the unit weight of the mix with respect to bitumen content.
  • Curve (D) represents the percentage of volume of mineral admixture in the mix with respect to bitumen content.

3.  With reference to the Marshall mix design criteria for highways, which one of the following parts is NOT correctly matched ?

[IES 1998]

  1. Flow value : 8 -16
  2. VFB : 50 – 75
  3. % Air Voids : 3 – 5
  4. Stability value : 340 (minimum)
Answer: Option B
Explanation:
Marshall mix design criteria for bituminous concrete is
  • Marshall stability = 340 kg (minimum)
  • Flow value, 0.25 mm units = 8 to 16
  • Percentage of air voids in total mix = 3 to 5%
  • Percentage of voids filled with bitumen =75 to 85%

4.  Assertion (A): In bituminous mixes, the minimum voids requirement provides space for densification under traffic movements and expansion of bitumen at high temperature.

Reason (R): Insufficient voids in the bituminous mix causes bleeding of the bituminous surface and skidding. 

[IES 1999]

  1. Both A and R are true and R is the correct explanation of A.
  2. Both A and R are true but R is not a correct explanation of A.
  3. A is true but R is false.
  4. A is false but R is true.
Answer: Option A
Explanation:
In case of bituminous mixes, the requirement of minimum percentage of air voids ensures compaction under traffic movement and expansion of bitumen at high temperatures. Lack of voids in the bituminous mix can cause bleeding of the bituminous surface and skidding.

5.  Which one of the following curves illustrates the correct relation between % voids in total mix and % bitumen ?

[IES 2000]

Answer: Option A
Explanation:
  • The percentage of voids in the total mix decreases with increase in bitumen content. Curve (A) represents the percentage of voids in the total mix with respect to bitumen content.
  • Curve (B) and (C) represents the flow value of the mix with respect to bitumen content.
  • Curve (D) represents the percentage of voids filled with bitumen with respect to bitumen content.

6.  Assertion (A): The Marshall test, being a confined compression test has a correlation with deformation as it occurs on the road.

Reason (R): In road, loaded area is confined by the tyre, the surrounding surfacing and the road base. 

[IES 2002]

  1. Both A and R are true and R is the correct explanation of A.
  2. Both A and R are true but R is not a correct explanation of A.
  3. A is true but R is false.
  4. A is false but R is true.
Answer: Option D
Explanation:
Marshall test is an unconfined compression test as there is no cell pressure applied.

7.  Which one of the following diagrams illustrates the relationship between flow value (FV) and percentage bitumen (%BIT) ?

[IES 2006]

Answer: Option A
Explanation:
  • Curve (A) represents the percentage of voids in the total mix with respect to bitumen content.
  • Curve (B) represents Marshall stability or unit weight of the mix with respect to bitumen content.
  • Curve (C) represents the flow value of the mix with respect to bitumen content. The flow value of the mix increases with increase in bitumen content, but it is concave upwards.
  • Curve (D) represents the percentage of voids filled with bitumen with respect to bitumen content.
PYQs of Competitive Exams :
Join Us On:
Scroll to Top