What is the last step in the design of flexible pavement? Explanation: The last step in the design of the pavement is
design of pavement thickness
, after design of mix, design of sub grade, sub base and base. Explanation: If one or more wheels act as a single load then it is called as an equivalent single wheel load.
Which factor does not affect the pavement design Sanfoundry?
Explanation: The
weather factor
is not considered in CBR method as it keeps changing frequently, growth rate keeps increasing, VDF is a constant so climate doesn’t actually affect the CBR. Sanfoundry Global Education & Learning Series – Highway Engineering.
What are the design steps of flexible pavement?
A flexible pavement structure is typically composed of several layers of materials.
Each layer receives loads from the above layer, spreads them out, and passes on these loads to the next layer below
. Thus the stresses will be reduced, which are maximum at the top layer and minimum on the top of subgrade.
Which of the following layers of the flexible pavement should have highest modulus of elasticity?
13. The layer which should have high modulus of elasticity is? Explanation: The modulus of elasticity should increase as the
pavement layer increase from bottom to top
.
What is the life of flexible pavement?
Explanation: The design life of flexible pavement is considered as
15 years
, it may last even further if properly maintained. Explanation: The design period of cement roads is usually taken as 30 years but they can even last longer if properly maintained and designed.
What is effective CBR value?
▪
Composite strength of the subgrade and the embankment soil below
it is termed as EFFECTIVE CBR. ▪ This composite strength should be taken for design consideration ▪ This composite strength should be taken for design consideration rather than strength of top 500mm.
What are the layers of flexible pavement?
Typical layers of a conventional flexible pavement includes
seal coat, surface course, tack coat, binder course, prime coat, base course, sub-base course, compacted sub-grade, and natural sub- grade
. Seal Coat: Seal coat is a thin surface treatment used to water-proof the surface and to provide skid resistance.
What are the factors considered in pavement design?
Traffic is the most important factor in the pavement design. The key factors include
contact pressure, wheel load, axle configuration, moving loads, load, and load repetitions
.
Which layer of pavement should withstand stress?
The lower layers are the base courses.
The surface course
constitutes the top layer of the pavement and should be able to withstand high traffic- and environmentally-induced stresses without exhibiting unsatisfactory cracking and rutting.
Which bitumen does not need heating?
Which bitumen does not need heating? Explanation:
The cutback bitumen
which is the most economical type may or may not require heating, whereas the remaining required to be heated.
Which type of pavement has multiple layers?
A composite pavement
comprises multiple, structurally different layers of heterogeneous nature. A typical example is a concrete pavement of two layers, sandwiching a brick layer. A base of roller compacted concrete and surface course of bitumen is another example.
What is Burmister theory?
Burmister developed the
two layer theory
in 1943. • As known the flexible pavement sections are composed of layers. • The effect of layers above subgrade is to reduce the stress and deflections in the subgrade.
What is difference between flexible and rigid pavement?
Flexible pavements tend to have more layers and are therefore much thicker by default.
Rigid pavements have fewer layers and are thinner than flexible pavements
, which makes them susceptible to more repairs over time.
Where is flexible pavement used?
Major highways constructed in the world are of bituminous surfacing. For example, 86 percent of
rural highways
and 78 percent of urban roads in the U.S. are of flexible type. Most of the runways in the world have flexible pavements, Autobahn in Germany is also with flexible pavement.
What is flexible pavement used for?
The concrete slab itself supplies most of a rigid pavement’s structural capacity. Flexible pavement uses more
flexible surface course and distributes loads over a smaller area
. It relies on a combination of layers for transmitting load to the subgrade.
How many types of flexible pavements are there?
Types of Flexible Pavements
Conventional layered flexible pavement, Full – depth asphalt pavement, and
.
Contained rock asphalt mat
(CRAM).
