This set of Pavement Design Multiple Choice Questions & Answers (MCQs) focuses on “Highway Maintenance – Geosynthetics in Pavement”.
1. What is the name of the product that has a geosynthetic as well as another material in it?
Explanation: Geosynthetic is actually a broad term that has many materials and a wide range of mixes in it. Generally, geotextiles and geogrids were in use, but now geocomposites are being used. These are a mix of geosynthetic and other materials.
2. The use of geosynthetics in the hot mix asphalt overlays is to reduce the ______
b) Block cracking
c) Reflective cracking
d) Joint cracking
Explanation: Reflective cracking is a defect common in hot mix asphalt overlays that are placed over an existing rigid pavement. So, in order to prevent that, geosynthetics can be applied to the pavement mix.
3. Geosynthetics can be used in the pavement to resist the moisture intrusion into underlying layers.
Explanation: One of the functions of the construction of pavement using geosynthetic is to resist the intrusion of moisture into the underlying pavement layers. The type of geosynthetic is used such that the water intrusion can be avoided.
4. Which of the below is not a type of geocomposite?
Explanation: Geoshell is a software used in the windows systems and not a type of geocomposite. Geogrid, geomesh, geonet, geoweb are all different types of geocomposites that are made with geotextile and other materials.
5. ______ can be considered as a three-dimensional grid that can be used to confine unbound low cohesion materials.
Explanation: Geocell is an advanced geosynthetic material that forms three-dimensional confinement over materials having low cohesion. These are much effective in reducing the thickness of the pavement because they provide great quality confinement.
6. Geo pipes are used for ______
a) Transmitting water
Explanation: Geo pipes are perforated or solid pipes that are used for the drainage of liquids and gases. The leachate and gas from the landfills can be transmitted through these pipes. These are sometimes wrapped with geotextile filters.
7. The geosynthetic clay liners are made with ______ and geotextile.
Explanation: The geosynthetic clay liners are geocomposites that are used as liners. These are made of geotextile and bentonite. A layer of bentonite is sandwiched between geotextile layers.
8. What is the yarn running along the length of a woven geotextile called?
Explanation: A woven geotextile has threads running in both directions just like the regular woven textiles. The yarn running along the length is called the warp and the one running perpendicular to it is called weft.
9. Geo webs are manufactured as per the quality standards in ______
a) IRC 1009
b) IRC 9001
c) ISO 1009
d) ISO 9001
Explanation: Geo webs is another product that uses geosynthetics to provide confinement to the soils and aggregates. The ISO 9001 gives the quality standard to be followed for the manufacturing the Geoweb geocell cellular confinement systems.
10. Geotextiles can be placed in between two layers of the pavement to ______
a) Strengthen them
b) Interlock them
c) Separate them
d) Protect them
Explanation: The main purpose of placing a layer of geotextile between the pavement layers is to separate them. The grades of the materials in each layer are different, and in an attempt to differentiate them, the geotextile layer is introduced. It helps in keeping the fines from mixing with the coarse aggregates.
11. Which of the below has high strain characteristics?
a) Woven geotextile
c) Non-woven geotextile
Explanation: The non-woven geotextile is found to have more strain and low strength characteristics when tested. This is attributed to the non-interwining of each thread of the geotextile. In woven, geogrid and geonet geosynthetics, the threads are interconnected and form a strong bond.
12. What is another name used to refer to a geonet sometimes?
Explanation: A geonet is also called geospacers. These are planar products that consist of ribs running in two directions. The aperture is diamond-shaped. The thickness of these is greater than geogrids. Geomesh is another product.
13. A geotextile is not good at which of the below functions?
Explanation: The geotextile is used in the pavement to serve the following functions – separation, drainage, reinforcement and filtration. It does not help in the containment of the materials. The confinement is done by the geosynthetic clay liners and geocells.
14. Which product is used in pavements subjected to excessive freezing and thawing conditions?
Explanation: Geofoam is a type of geosynthetic that is made up of polystyrene. It is in the form of lightweight blocks of varying sizes. They have low density and high strength. These are used in the roadways under freeze-thaw cycles because of their nature.
15. Geogrids are used only for reinforcement.
Explanation: Geogrids are used exclusively for the reinforcement of pavement materials. They have low strain and more strength compared to other types of geosynthetics. Geotextiles, geocomposites and geocells can also be used for reinforcement.
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.