Design of Flexible Pavements – OL426 (23 PDH)

Quiz Answers – Design of Flexible Pavements

1.	Major defect types that can be observed on flexible pavements are:
		Cracking
		Deformations
		Disintegration and wear
	⊗	All of the above
2.	The results of the AASHO road test are still used today.
	⊗	True
		False
3.	The AASHTO design method had the drawback of being:
		Too easy
		Long
	⊗	Empirical
		None of the above
4.	The cracks in the picture below is due to:
		High temperature
	⊗	Low temperature
		Rain
		None of the above
5.	Raveling, bleeding and pothole formation can be rated as signs of:
		Disintegration
		Wear
	⊗	Both
6.	The Timber truck in the picture below is completely stuck on an earth road due to too ________ contact pressures and a too low shear resistance of the pavement material.
	⊗	Low
		High
7.	A system with a stiffer layer on top of a softer half space is called a ___________ layer system.
		One
	⊗	Two
		Three
		Four
8.	If the horizontal tensile stress at the bottom of the top layer is too high, it will be the cause for cracking of the __________ layer.
	⊗	Top
		Bottom
9.	________________ shear stresses act in the longitudinal and transverse direction
		Vertical
	⊗	Horizontal
10.	Knowledge on axle and wheel loads is important but even more so is knowledge on the contact pressures.
	⊗	True
		False
11.	Temperature has a significant effect on the:
		stiffness
		fatigue
		permanent deformation resistance of asphalt mixtures
	⊗	All of the above
12.	TGP takes a ___________ value when the top part of the total asphalt thickness is softer than the bottom part.
		Negative
	⊗	Positive
13.	Moisture has a large effect on the ____________ and bearing capacity of soils and unbound materials
		Stength
	⊗	Stiffness
14.	Repeated load tests are needed to obtain the stiffness characteristics of asphalt mixtures in relation to the loading time and _______.
		Length
	⊗	Temperature
15.	The procedure proposed by the Belgian Road Research Centre is preferred since it is based on a dataset.
		More detailed
		Smaller
	⊗	Larger
		More accurate
16.	______________ of the asphalt mixture has to do with the fact that asphalt mixtures have the capacity to “repair” themselves.
		Peeling
		Straining
	⊗	Healing
		None of the above
17.	Because of lateral wander, the ______________ stresses and strains don’t always occur in the same location.
		Minimum
	⊗	Maximum
18.	Which one of the following does not affect the vertical stress at which shear failure occurs in a granular material?
		the amount of confinement
		the cohesion
		angle of internal friction of the material considered.
	⊗	the strain
19.	The picture below displays excessive pavement deformation due to deformation of the:
		bound base
	⊗	unbound base
20.	Van Niekerk’s work has also been used to develop relations for the allowable ____________ strain at the top of the unbound base or subbase.
	⊗	Vertical
		Horizontal
21.	Depending on the load transfer across these cracks, significant traffic induced tensile strains might develop to these cracks resulting in longitudinal cracking.
	⊗	Parallel
		Perpendicular

1. 4 – All of the Above
2. T
3. 3 – Empirical
4. 2 – Low Temperature
5. 3 – Both
6. 1 – Low
7. 2 – Two
8. Top
9. 2 – Horizontal
10. T
11. 4 – All
12. 2 – Positive
13. 2 – Stiffness
14. 2 – Temperature
15. 3 – Larger
16. 3 – Healing
17. Maximum
18. 4 – Strain
19. 2 – Unbound Base
20. Vertical
21. Parallel

100% correct answers: verified 06 Feb 2022

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