This set of Pavement Design Multiple Choice Questions & Answers (MCQs) focuses on “Bituminous Material Properties”.
1. Tar is no longer used as a binder in pavements because of its ______
c) Temperature susceptibility
d) Colour change
Explanation: The binder used are bitumen and tar. The colour of tar is black, it has similar viscosity and durability to the bitumen. The problem is the high temperature susceptibility. Also, it results in the release of harmful fumes when it is heated.
2. Which of the below is not a type of bitumen used in the construction of flexible pavements?
a) Oxidised bitumen
b) Cut-back bitumen
c) Modified bitumen
d) Bitumen emulsion
Explanation: Oxidised bitumen is prepared by oxidizing the refined bitumen. This reduces its ductility and can be used for non-road applications. It is employed for use in paints, roofing, adhesives, etc.
3. Bitumen is classified as hard and thin based on ______
Explanation: Bitumen is classified into hard and thin bitumen based on their application. Thin bitumen is used for road applications and hard bitumen is used for non-road applications like in paints, sealants, etc.
4. What does PMB stand for?
a) Polymer Modified Bitumen
b) Polymer Mix Bitumen
c) Penetration Modified Bitumen
d) Penetration Mix Bitumen
Explanation: PMB stands for Polymer Modified Bitumen. These are produced by adding polymers like styrene-butadiene-styrene (SBS), SBR, polyethylene, etc. The polymers help in modifying the properties of bitumen.
5. The paving grade bitumen is susceptible to temperature changes.
Explanation: The ordinary paving grade bitumen is susceptible to temperature changes. The road pavements become softer in summer and brittle in winter. This can be solved by adding modifiers to the bitumen.
6. The grades of bitumen used for non-road applications are called as ______ grade bitumen.
Explanation: There are two grades of bitumen based on application – one for road construction purpose and one for waterproofing structures. Paving grade bitumen is used for road construction purpose and industrial grade bitumen is used for other works.
7. Which of the below options represent the types of cut-back bitumen?
a) Rapid, medium and slow setting
b) Rapid and slow setting
c) Rapid, medium and slow curing
d) Rapid and slow curing
Explanation: Rapid, medium and slow curing are the different types of cut-back bitumen. Rapid, medium and slow setting are the types of bitumen emulsion.
8. Which type of bitumen has a volatile oil added to it?
a) Bitumen emulsion
Explanation: In cut-back bitumen, certain oil is added to it to reduce its viscosity. His is done to make it usable for application of tack coat. Modified bitumen has polymers added in it to improve properties. An emulsion is a liquid product and oxidized bitumen has low ductility.
9. What shows the first sign of the breakdown of bitumen emulsion?
a) Texture change
b) Colour change
c) Odour change
d) Temperature change
Explanation: Bitumen emulsion consists of a liquid base in which bitumen is dispersed as small droplets. The initial colour is chocolate brown when applied to the road. The colour changes to black and depicts the first sign of the breakdown of emulsion.
10. Which code gives the classification of modified bitumen?
a) IS 15464
b) IS 15466
c) IS 15468
d) IS 15462
Explanation: The IS code 15462 gives details on polymer and rubber modified bitumen. IS 15464 deals with ethanol for use in automotive fuel, IS 15466 deals with rubber seals for hydraulic gate and IS 15468 deals with performance evaluation of ultrasonic thickness gauges.
11. On what basis have the classifications RC, MC and SC been further classified into?
a) Amount of solvent
b) Temperature range
c) Rate of curing
d) Initial viscosity
Explanation: The oil is added to the bitumen to reduce its viscosity and the product is called cut-back bitumen. The classifications RC, MC and SC are based on the rate of curing and their further classifications are based on the initial kinematic viscosity.
12. What does an 80/100 grade bitumen indicate?
Explanation: Bitumen is graded in terms of penetration and viscosity. According to penetration grading, the 80/100 grading indicates that the penetration of bitumen is between 8 to 10 mm. Viscosity grading is represented by VG 10, which has penetration value in the range 8 to 10 mm.
13. Anionic bitumen emulsion is preferred in wet weather conditions.
Explanation: Anionic bitumen emulsion depends on the evaporation of the liquid. So, it depends on the climatic conditions and hence it is preferred in dry weather conditions.
14. ______ is a mixture containing bitumen and sand.
Explanation: Asphalt and bitumen are different in their composition. Asphalt is a mixture of bitumen (binder) and sand (mineral aggregate). Bitumen consists of hydrocarbons and is obtained by the distillation process of petroleum.
15. Which of the below abbreviation – full form pairs have been matched incorrectly?
a) HSS – high stress seal
b) SAMI – stress absorbing membrane interface
c) EVA – ethylene vinyl acetate
d) SAM – shear absorbing membrane
Explanation: All the above abbreviations are related to modified bitumen. SAM stands for strain/stress absorbing membrane. Modified bitumen has the advantage of improved resistance to cracking as SAM and SAMI. EVA is a modifier added to bitumen. HSS is a modified bitumen that is used for sealing applications.
Sanfoundry Global Education & Learning Series – Pavement Design.
To practice all areas of Pavement Design, here is complete set of 1000+ Multiple Choice Questions and Answers.