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Prof. Dr. Eng Shafik Jendia
Rigid Pavement
Lectures of 11., 12. Week11. Week 16. 11 - 22. 11 . 201312. Week 23. 11 - 29. 11 . 201313. Week 30.11 – 06.12. 2013
Prof. DR. Eng. Shafik Jendia
Islamic University of Gaza
Prof. Dr. Eng Shafik Jendia
ReferencesHighway Engineering, Structural Design, Shafik Jendia (Arabic Version) AASHTO, Guide for Design of Pavement Structures.
Concrete Pavement Design,Construction, and Performance. Norbert Delatte
RIGID PAVEMENT DESIGN MANUAL.PUBLISHED BY FLORIDA DEPARTMENT OF TRANSPORTATION PAVEMENT MANAGEMENT OFFICE
Concrete Pavement Design, Guidance Notes, Geoffrey Griffiths and Nick Thom
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Prof. Dr. Eng Shafik Jendia
Rigid Pavement
IntroductionAdvantages and disadvantages of rigid pavementStresses of rigid pavement Design and construction of pavement jointsReinforcementDesign of rigid pavementDiscussion
Prof. Dr. Eng Shafik Jendia
Introduction
Rigid Pavements have been used for highways, airports, local roads, parking lots, industrial facilities,
and other types of infrastructure.When properly designed and built out of durable materials, concrete pavements can provide many decades of service with little or no maintenance.
Concrete generally has a higher initial cost than asphalt but lasts longer and has lower maintenance costs.
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Prof. Dr. Eng Shafik Jendia
IntroductionRigid Pavement or
Cement Concrete Pavementcan be paved as reinforced or unreinforced slabs
with certain dimensions. Longitudinal and transverse joints separate the slabs from each
other .
Prof. Dr. Eng Shafik Jendia
IntroductionCement Concrete consists of
Aggregates, Cement and Water
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Prof. Dr. Eng Shafik Jendia
Produce of Rigid (Cement Concrete) Pavement
Introduction
Prof. Dr. Eng Shafik Jendia
Flexible (Asphalt) and
Rigid (Cement Concrete) Pavements
Introduction
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Prof. Dr. Eng Shafik Jendia
binder
wearing
Introduction
Prof. Dr. Eng Shafik Jendia
Other Example For Rigid Pavement
Introduction
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Prof. Dr. Eng Shafik Jendia
Rigid Pavement has specific advantageswhen compared with asphalt pavement:• It lasts longer due to its rigidity and strength.
• It consists of a system of stiff plates (slabs)connected together to form a continuous, hingedslab system.
• The specific advantage of a rigid pavement isthat the relatively rigid plates apply load over awide area.
Advantages and disadvantages of rigid pavement
Prof. Dr. Eng Shafik Jendia
Advantages and disadvantages of rigid pavement
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Prof. Dr. Eng Shafik Jendia
• Because of its high skid resistance andbrightness, it is safer than asphalt pavement.Brightness provides the night drivers with bettersight and safety.
• No rutting and no/ or slight deformation.
• The binder (cement) isn't affected by temperature(unlike bitumen).
Advantages and disadvantages of rigid pavement
Prof. Dr. Eng Shafik Jendia
Rigid Pavements have specific disadvantageswhen compared with asphalt pavements:
• Rigid Pavement has a higher initial cost thanasphalt, thus it has been used for airports, heavilyloaded highways, industrial facilities and otherspecial types of infrastructure.
• The Joints between the slabs can be considered asa source for failures.
• It is not preferable to be used in urban roads,because of maintenance difficulties of infrastructurefacilities.
Advantages and disadvantages of rigid pavement
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid PavementThe concrete slab of the rigid pavement faces different types of stresses caused by repeated traffic load, temperature, moisture etc. which lead to: buckling, expansion, contraction and warping of the slab.Thus the designed slab must have high strength to resist all these effects. This means that the design Engineer should take into consideration in addition to traffic load and weather conditions: type of concrete, dimension of slabs, joints and their construction, the necessity of reinforcement and base type below.
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement
• Wheel Load Stress
• Warping Stress
• Frictional Stress
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load StressCritical Location of Loading
according Westergard
Interior Loading Edge Loading Corner Loading
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load StressStresses at Critical Location of Loading modified by
Westergard, Teller, Sutherland and Kelly.
Interior Loading
Edge Loading
Corner Loading
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load Stress
Where:
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load Stress
Example 1: Calculate
the stresses caused by a vehicle
wheel (P) at all critical
locations of a cement concrete
pavement.
Given:
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load Stress
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load Stress
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load Stress
Example 2: Calculate the
stresses caused by a vehicle wheel (P) at corners of cement concrete
slabs with the thicknesses:
h = 10 cm, 15 cm, 20 cm, 22 cm,
for the data given in example 1
Solution
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load Stress
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load Stress
Example 3: Calculate the
stresses caused by a vehicle wheel
(P) at edges of cement concrete
slabs with the thicknesses:
h = 10 cm, 15 cm, 20 cm, 22 cm,
for the data given in example 1
Solution
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load Stress
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load Stress
Example 4: Calculate the
stresses caused by a vehicle wheel
(P) interior of cement concrete
slabs with the thicknesses:
h = 10 cm, 15 cm, 20 cm, 22 cm,
for the data given in example 1
Solution
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load Stress
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load StressRelationship between slab thickness and wheel load
stresses at the three critical locations
3
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load StressConclusions
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load StressSlab Deflection W
here:
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load StressExample 5: Calculate
the deflections caused by a vehicle
wheel (P) at all critical
locations of a cement concrete
pavement.
Given:
α = 200 mm
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Wheel Load StressSlab Deflection/ solution
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping Stresses
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping StressesSummer Midday
Temperature Distribution over the slab thickness
Slab Deformation Summer Midday
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping Stresses
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping StressesWinter Midnight
Temperature Distribution over the slab thickness
Slab Deformation Winter Midnight
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping Stresses
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping Stresses
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping Stresses
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping StressesExample 6: Calculate
the warping Stresses at interior and
edgelocations of a cement concrete
pavement.
Given:
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping Stresses
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping Stresses
Given:
= 15 cmExample 7: Calculate
the warping Stresses at interior and
edgelocations of a cement concrete
pavement.
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Warping Stresses
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Frictional Stress
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Frictional Stress
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Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / Frictional Stresses
Example 8: Calculate the
frictional stresses if the length of
cement concrete slabs:
L= 5 m, 10 m, 20 m,
Solution
Compared with other stresses, the frictional stress is relatively low. It affects the edge and interior of the
slab. It is considered in winter tensile and in summer compressive stress.
Prof. Dr. Eng Shafik Jendia
Stresses of Rigid Pavement / CombinationDuring Summer: The critical combinations for interior and edge during mid day exists when the slab tends to warp downward.
At this moment tensile stresses develop at the bottom fibre which are additive to the tensile stresses due to the loading.
σ(total) = σ(Load) + σ(warping) - σ(friction).
During Winter: The critical combinations for interior and edge exists when the slab contracts and the slab warps downward
during the midnight. σ(total) = σ(Load) + σ(warping) +σ(friction).
Since the Δt during winter lower than in summer, the combination during summer is the worst in our country
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Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints
Although the existing of joints in the rigid pavement can be considered sometimes as a
reason of distresses in the pavement, their construction in the rigid slab is very
necessary. Through joints, thermal stresses can be minimized. This means while the joints
carry stresses induced by expansion, contraction and warping of the slab, the slab resists all stresses caused by wheel loading.
Prof. Dr. Eng Shafik Jendia
Design and Construction of Pavement Joints
Joints can be divided according to their locations into two types:
• Transverse Joints: are perpendicular to the centerline of the roadway (at right angle to the traffic direction) .
• Longitudinal Joints: are parallel to the centerline (the same direction of traffic)
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Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints
Joints can be divided according to their functions into three types:
- Expansion Joints- Contraction Joints- Construction Joints
Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints/ Expansion Joints
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Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints/ Expansion Joints
Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints/ Expansion Joints
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Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints/ Expansion Joints
Jointed plain concrete pavement (JPCP) or unreinforced concrete pavement (URC)
Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints/ Expansion Joints
Jointed reinforced concrete pavement (JRCP) or jointed reinforced concrete (JRC) pavement
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Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints/ Expansion Joints
Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints/ Contraction Joints
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Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints/ Contraction Joints
Prof. Dr. Eng Shafik Jendia
Aggregate interlock joints are formed during construction by sawing
1/4−1/3 of the way through the pavement to create a plane of weakness. A
crack then propagates through the remaining thickness of the pavement as
the concrete contracts. This crack has a rough surface because it propagates
around the aggregates through the green cement paste, and as long as
it remains narrow the joint can transfer load from one slab to another
through bearing stress of the aggregate particles against each other across
the crack. Load transfer is compromised if the joint opens too widely or if
the aggregates wear away. The quality and erosion resistance of the material
supporting the slab at the joint also affect load transfer.
Design and construction of pavement joints/ Contraction Joints/ Aggregate interlock
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Prof. Dr. Eng Shafik Jendia
Design and construction of pavement joints/ Longitudinal Joints and Construction Joints
Prof. Dr. Eng Shafik Jendia
Reinforcement of Rigid Pavement
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Prof. Dr. Eng Shafik Jendia
Reinforcement of Rigid Pavement
Time
Tens
ile S
tres
s
Tem
pera
ture
Relationship between temperature variation of (concrete direct after laying due to hydration and tensile stress) and time
Prof. Dr. Eng Shafik Jendia
Reinforcement of Rigid Pavement
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Prof. Dr. Eng Shafik Jendia
Reinforcement of Rigid Pavement
Prof. Dr. Eng Shafik Jendia
Reinforcement of Rigid Pavement
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Prof. Dr. Eng Shafik Jendia
Reinforcement of Rigid Pavement
Prof. Dr. Eng Shafik Jendia
Reinforcement of Rigid Pavement
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Prof. Dr. Eng Shafik Jendia
Reinforcement of Rigid Pavement
Prof. Dr. Eng Shafik Jendia
Reinforcement of Rigid Pavement
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Prof. Dr. Eng Shafik Jendia
Design of rigid pavement
Prof. Dr. Eng Shafik Jendia
Design of rigid pavementModulus of Subgrade Reaction
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Prof. Dr. Eng Shafik Jendia
Design of rigid pavementPCC Elastic Modulus
Prof. Dr. Eng Shafik Jendia
Design of rigid pavementPCC Modulus of Rupture
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Prof. Dr. Eng Shafik Jendia
Design of rigid pavementPCC Modulus of Rupture S’C or (fT)
fT
fC
fT = 0.79 (fC ) 0.5
Third Point Loading
Prof. Dr. Eng Shafik Jendia
Design of rigid pavementLoad Transfer coefficient J
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Prof. Dr. Eng Shafik Jendia
Design of rigid pavementLoad Transfer coefficient J
.
Prof. Dr. Eng Shafik Jendia
Design of rigid pavementDrainage Coefficient Cd
.
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Prof. Dr. Eng Shafik Jendia
Design of rigid pavement
Example
Prof. Dr. Eng Shafik Jendia
Design of rigid pavement
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Prof. Dr. Eng Shafik Jendia
Design of rigid pavement
Prof. Dr. Eng Shafik Jendia
Design of rigid pavement / Example
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Prof. Dr. Eng Shafik Jendia
Design of rigid pavement / Example
Prof. Dr. Eng Shafik Jendia
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Prof. Dr. Eng Shafik Jendia
Prof. Dr. Eng Shafik Jendia