What is the main design criteria for designing the rigid pavement?
What is the main design criterion for designing the rigid pavement? Explanation: Rigid pavement is not flexible i.e. it is not elastic in nature. The deformations once formed due to the tensile stress are not reversible. They tend to develop into big cracks later on.
What are pavement design methods?
Two methods of flexible pavement structural design are common today: Empirical design and mechanistic empirical design.
What are the steps for the thickness design of rigid pavements as per IRC guidelines?
The following steps may be used for this purpose:
- Assume a trial thickness for the slab.
- Calculate the stresses due to load [σe and σc from Eq.
- Calculate the stress ratio (SR) by dividing the edge stress due to load by the flexural strength of the concrete (modulus of rupture, MR)
What is the thickness of rigid pavement?
The minimum thickness of reinforced concrete pavements should be 6 inches, except that the minimum thickness for driveways will be 5 inches and the minimum thickness for reinforced overlays over rigid pavements will be 4 inches.
What is the main aim of the pavement design process?
What is the main aim of the pavement design process? Explanation: The pavement design mainly aims at determining the total thickness of the pavement. The thickness of each layer of the pavement is found out by designing it with proper inputs and then the total thickness is found out.
What is IRC 37?
The Pavement designs given in the previous edition IRC:37-1984 were applicable to design traffic upto only 30 million standard axles (msa). These guidelines will apply to design of flexible pavements for Expressway, National Highways, State Highways, Major District Roads, and other categories of roads.
What is IRC method?
The design procedure given by IRC makes use of the CBR value, million standard axle concept, and vehicle damage factor. Traffic distribution along the lanes are taken into account. The design is meant for design traffic which is arrived at using a growth rate. Introduction to Transportation Engineering.
What is CBR in pavement design?
The California Bearing Ratio (CBR) is a measure of the strength of the subgrade of a road or other paved area, and of the materials used in its construction. Empirical tests measure the strength of the material and are not a true representation of the resilient modulus.
How many layers are there in rigid pavement?
A rigid pavement structure is typically composed of a PCC surface course built on top of either (1) the subgrade or (2) an underlying base course. Because of its relative rigidity, the pavement structure distributes loads over a wide area with only one, or at most two, structural layers (see Figure 1).
Why cement is used in rigid pavement?
The rigid pavement slab as tensile strength , tensile stresses are developed due to the bending of the slab under the wheel load temperature variations Providing a good base at sub base course layer under the cement concrete slab increase the pavement life considerably and there for workout more economical in the long …
What is the most important while designing a pavement?
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.
What is rigidity factor?
Explanation: Rigidity factor is the ratio between contact pressure and tyre pressure. When the tyre pressure is 7 kg/cm2, it is equal to the contact pressure. When the tyre pressure is more than the contact pressure, the rigidity factor is less than one.
What do you need to know about rigid pavement design?
The following input variables are needed for the AASHTO rigid pavement design procedure. The M r of concrete is a measure of the flexural strength of the concrete as determined by breaking concrete beam test specimens. An M r of 620 psi at 28 days should be used with the current statewide specification for concrete pavement design.
What do you need to know about CPCD pavement design?
CPCD Pavement Design Process. The following input variables are needed for the AASHTO rigid pavement design procedure. The M r of concrete is a measure of the flexural strength of the concrete as determined by breaking concrete beam test specimens.
What are the different types of pavements used for?
Different pavement types use different types of joints and reinforcement to control the forces acting on the concrete pavement. These forces include drying shrinkage of the concrete, environment changes, and traffic loads.
Which is the drainage layer of rigid pavement?
Granular sub-base (GSB) or drainage layer: • The GSB course has to serve as an effective drainage layer of the rigid pavement to prevent early failures due to content in the subgrade soil.