This document provides an overview of continuously reinforced concrete pavement (CRCP). It discusses the characteristics and importance of CRCP, including that it is a rigid pavement without joints that requires little maintenance. The document outlines various design considerations and factors like crack spacing, width, and steel reinforcement. It also describes the typical design process involving calculating the required steel percentage based on parameters like concrete strength and temperature differentials. Finally, it provides an example of a typical CRCP design with specifications.

1. CONTINUOUS
REINFORCED
RIGID PAVEMENT
Bhavya S. Jaiswal
Btech civil,
Mtech
Transportation
Engineering

2. Content of The Presentation
◦ Introduction
◦ Characteristics and importance
◦ Design and performance factors
◦ Design steps
◦ Typical design of CRCP
Prepared by: Bhavya S. Jaiswal

3. Introduction
◦ The CRCP which means Continuous Reinforced Rigid Pavement.
◦ It is a pavement which doesn't not have any joints within it is having a continuous reinforcement.
◦ These are the pavement which usually not requires any type of regular maintenance in fact Once
CRCP roads are constructed they need not to be taken care of for the next 50-60 years.
◦ However, the minor and tight transverse cracks are observed in the pavment.
Prepared by: Bhavya S. Jaiswal

4. Characteristics and importance
◦ Flexible pavement (bitumen) is most common for both national
and state highways. Majority of roads are also built with
conventional bitumen pavements considering its lower initial
cost, though the life cycle cost of these pavements are very
high compared to rigid pavements due to frequent repairs and
need for complete resurfacing at interval of 4-5 years.
Continuous reinforced concrete
Bituminous aggregate mix
Aggregate subbase
6’’
4’’
10’’
o In advanced countries rigid pavement is increasingly being used due to large number of benefits it offers.
o And beneficially, Continuously reinforced concrete pavement, eliminates the need for transverse joints and keep
cracks tight, resulting in a continuous, smooth-riding surface that is virtually maintenance free.
Prepared by: Bhavya S. Jaiswal

5. Design consideration and performance factors
Design consideration
Design Aspects:
• Crack Spacing
• Crack width
Steel stress
• Steel Reinforcement
• Longitudinal Reinforcing Bars
• Transverse Reinforcing Bars
Prepared by: Bhavya S. Jaiswal

6. Design consideration
◦ Crack Spacing:
 The limits on crack spacing are based on the possibility of spalling and punch outs.
 However, the maximum spacing between consecutive cracks should be limited to 2.4m to minimize
spalling. To minimize the potential of punch outs, the minimum desirable crack spacing is about 1.1m.
◦ Crack width:
 The limit on crack width is based on a consideration of spalling and water infiltration.
 The crack width should be reduced as much as possible through the selection of higher steel percentage
or smaller diameter reinforcing bars. But As per AASHTO stipulation the allowable crack width should
not exceed 1.0mm.
Prepared by: Bhavya S. Jaiswal

7. Design consideration
◦ Steel Reinforcement:
 Depth and the total provided number of bars is a most important thing as It affects transverse crack spacing
and the width of the cracks.
 he longitudinal reinforcement in CRCP is used to control the fine transverse cracks that form due to volume
changes in the concrete. The function of steel is to hold the random cracks tightly closed, to provide structural
continuity and to minimize the penetration of potentially damaging surface water and incompressible.
◦ Longitudinal Reinforcing Bars:
 The total area of longitudinal reinforcing bars required is stated as a percentage of the cross-sectional area of
the pavement.
 The amount of longitudinal reinforcing bars is generally between 0.5% and 0.7% and it may be more where
weather conditions are severe and also the temperature differentials are more.
Prepared by: Bhavya S. Jaiswal

8. Design consideration
◦ Transverse Reinforcing Bars:
Transverse reinforcements are useful to support the longitudinal steel when the steel is preset
prior to concrete placement.
The Transverse reinforcement used are may be lesser grade.
Thus, the functions of the transverse bars are…
1. To support the longitudinal bars and hold them at the specified spacing. When used for this
purpose, the longitudinal bars are tied or clipped to the transverse steel at specified locations.
2. To hold unplanned longitudinal cracks that may occur tightly closed.
Prepared by: Bhavya S. Jaiswal

9. Performance Factors
◦ These are the self-explanatory parameters which can be listed as followed:
Temperature
Humidity
Thermal contraction
Curing period
Material properties such as cement, aggregate
Proportion of the component
Prepared by: Bhavya S. Jaiswal

10. Design steps
1. The design is performed using the worksheet
given in the Table3.5,AASHTO’93. In the
table, space is given to input the values
2. Also, there is a separate worksheet in the
table3.6,AASHTO’93 for the design revision
Prepared by: Bhavya S. Jaiswal

11. Design steps
Here are the design inputs that are required for the design performance:
𝑓𝑡= concrete indirect tensile strength
𝑍= concrete shrinkage at 28 days
𝛼𝑐= concrete thermal coefficient
𝜑= bar diameter
𝛼𝑠= steel thermal coefficient
𝐷𝑇𝐷= design temperature drop
Prepared by: Bhavya S. Jaiswal

12. Design steps
3. After obtaining the slab thickness same as per the rigid pavement, Obtain the required
amount of the steel reinforcement using the design chart fig 3.10, 3.11, 3.12 and
record the resulting steel percentage and put that into the table3.5.
4. If P𝑚𝑎𝑥 < Pmin than…
 find which design value should be revised
Add those revised values in the worksheet 3.6 and also check if it affects the subbase
and slab thickness because sometimes it is maybe necessary to revaluate the subbase
and slab thickness.
Prepared by: Bhavya S. Jaiswal

13. Design steps
5. If the P𝑚𝑎𝑥 > Pmin than perform another step as…
 determine the range of the number of the reinforcement bars as:
𝑁𝑚𝑖𝑛 = 0.01273 × 𝑃𝑚𝑖𝑛 × 𝑊
𝑠 × 𝐷
𝜑2
𝑁𝑚𝑎𝑥 = 0.01273 × 𝑃𝑚𝑎𝑥 × 𝑊
𝑠 × 𝐷
𝜑2
Where,
Nmin= minimum number of bars
Nmax= maximum number of bars
Pmin= minimum steel % required
Pmax= maximum steel % required
𝑊
𝑠= total width of the pavement section
D= thickness of the concrete layer
𝜑= diameter of the bars
Prepared by: Bhavya S. Jaiswal

14. Design steps
6. Determine the final steel design by selecting the total number of steel bars in
the final design section as Ndesign which lies between Nmin and Nmax.
Prepared by: Bhavya S. Jaiswal

15. Typical design of CRCP
◦ The following parameters are considered for design:
◦ Design Life -> (a) 20 years for Flexible pavement (b) 30 years for Rigid pavements.
◦ Traffic Density ->(a) 5000 Vehicles/day on 4-lane road
◦ For Rigid Pavements:
◦ Concrete grade: M40
◦ Grade of steel: Fe 415
◦ Maximum temperature differential between top and bottom of Slab = 21°C (The maximum value for India as per IRC 58)
◦ Difference between mean temperatures of the slab at the time of construction and coldest period = 30°C (Assuming 35°C at
the time of construction and 5°C at coldest period)
Prepared by: Bhavya S. Jaiswal

16. Typical design of CRCP
Sr. item CRCP
1 Design Code AASHTO’93
2 Total pavement thickness (mm) 610
3 Grade of concrete M40
4 Spacing of contraction joints -
5 Steel reinforcement 0.57% long – 16 mm @ 140mm c/c Trans
– 12 mm @ 600mm c/c
6 Durability >30 years
7 Saving in Fuel 10-20%
8 Maintenance Very less
9 World experience Very good reports. 4500 km in USA; all
states have started using CRCP
10 Construction More special care needed
11 Expertise in the country yes
12 Corrosion problem No corrosion problem.
Prepared by: Bhavya S. Jaiswal

17. References
◦ IRC 58:2015: https://documentcloud.adobe.com/link/review?uri=urn:aaid:scds:US:94896878-
b990-46b8-a13e-50c7cd03b0d0
◦ AASHTO 1993: https://habib00ugm.files.wordpress.com/2010/05/aashto1993.pdf
◦ CEP civil Engineering portal: https://www.engineeringcivil.com/continuously-reinforced-
concrete-pavement.html
Prepared by: Bhavya S. Jaiswal