This set of Pavement Design Multiple Choice Questions & Answers focuses on “Soil-Bitumen Stabilization – 2”.
1. Bitumen emulsion is the most commonly used material for the bitumen and soil stabilization in any place.
Explanation: Bitumen emulsion and cut back bitumen are tye two commonly used materials. Bitumen emulsion is commonly used in areas having scarce availability of water.
2. Which of the below soil type and principle involved has been matched correctly?
a) Cohesive – binding
b) Fine-grained – binding
c) Non-cohesive – waterproofing
d) Coarse-grained – binding
Explanation: The main principle involved in the bitumen stabilization of cohesive and fine-grained soils is waterproofing. The principle involved in the case of non-cohesive and coarse-grained soil it is binding.
3. What governs the density of the soil and bitumen mixture?
a) Moisture content
b) Volatile content
c) Mineral content
d) Clay content
Explanation: The density of soil and bitumen mixture is governed by two factors – volatile content and compaction. Generally, lower volatile content provides more density and thus higher strength to the mix.
4. The uniformity of the mix can be determined by ______
a) Visual inspection
b) Blend uniformity
c) Content uniformity
d) Colour uniformity
Explanation: Uniformity of the mix can be easily determined by the visual inspection of the mixture of soil and bitumen. When bitumen emulsion breaks, it changes colour from brown to black. Blend and content uniformity are terms related to the pharmaceutical industry.
5. At what stage does the initial curing occur?
Explanation: It is necessary to allow initial curing so as to support the equipment for compaction of the mixture. The initial curing is provided during the aeration stage. The initial curing results from the evaporation of diluents from the mixture.
6. In frost areas, the soil-bitumen stabilization can be done using tar.
Explanation: Tar is highly susceptible to temperature changes and hence cannot be used in frost areas. Asphalt is less affected by temperature changes and can be used in frost areas for soil stabilization.
7. What is the right particle size consideration of soil for stabilization using bitumen?
a) Passing 0.425 mm sieve > 50%
b) Passing 4.75 mm sieve > 50%
c) Passing 0.425 mm sieve < 50%
d) Passing 4.75 mm sieve < 50%
Explanation: The soil particles passing 4.75 mm sieve must be less than 50%. The particles passing 0.425 mm sieve must be in between 35 to 100%. These properties of soil with respect to their particle size are desired for stabilization using bitumen.
8. The anti-stripping agent amine is not used with ______
Explanation: To impart resistance against the stripping of bitumen from the soil particles and aggregates, additives like anti-stripping agents are added. They can be polyphosphoric, silane and amino. Amino is generally used with porphyry, basalt and granite. Polyphosphoric and silane can be used with porphyry, granite, basalt and limestone.
9. What is the range of percentage of the weight of dry soil corresponding to which the optimum bitumen content is taken?
a) 4 to 10%
b) 5 to 10%
c) 4 to 6%
d) 5 to 6%
Explanation: The optimum bitumen content, OBC for the maximum stability is obtained at 4 to 6% by weight of dry soil. It varies according to the type of soil. The stability increase with an increase in bitumen content until a point, then it decreases.
10. What does the relative affinity of soil particles for water and bitumen depend on?
a) Surface chemicals
b) Cohesiveness of soil
c) Surface tension
Explanation: The relative affinity of soil particles for water and bitumen depend upon the surface chemical factors. Cations like calcium, aluminium and potassium are desired because of their less affinity to water. Chemical additives can be used to exchange undesirable cations.
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.