1. 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.
2. Which type of bitumen has a volatile oil added to it?
a) Bitumen emulsion
b) Modified
c) Cut-back
d) Oxidised
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.
3. 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.
4. 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.
5. 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.
6. What does an 80/100 grade bitumen indicate?
a) Viscosity
b) Temperature
c) Penetration
d) Proportion
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.
7. Anionic bitumen emulsion is preferred in wet weather conditions.
a) true
b) false
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.
8. ______ is a mixture containing bitumen and sand.
a) Binder
b) Asphalt
c) Tar
d) Filler
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.
9. 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.
10. For how long is the needle allowed to penetrate in the penetration test?
a) 5 seconds
b) 5 minutes
c) 10 seconds
d) 10 minutes
Explanation: The guidelines for the penetration test have been laid down in IS 1203. As per the same, the time allotted to the needle for penetration into the sample is 5 seconds. There are machines that automatically stop the penetration at the end of 5 seconds.