1. Long-Life Concrete Pavements InLong-Life Concrete Pavements In
The WorldThe World
Submitted to : Assoc.Prof. Mustafa SAHMARANSubmitted to : Assoc.Prof. Mustafa SAHMARAN
Prepared BY :Prepared BY : Hazhar HayderHazhar Hayder
Samadar SalimSamadar Salim
1

2. 2
This Search is about LLCP in
these Countries:
Canada
Germany
Austria
Belgium
Netherlands
United Kingdom

3. 3
The motivation for an international scan of long-life
concrete pavement technology:
1 - Safety
2 - Mitigation of congestion

4. Aging highway system
Heavier truck loads
High maintenance costs
Congestion
Work Zone Safety
Noise
44

5. 5
Background
Why long life?
––Reduce future maintenance and
rehabilitation requirements
–– Minimize traffic disruptions
–– Reduce user costs
–– Increase safety (fewer work zones)
–– Reduce life-cycle costs

6. 6
Solution
30--60 year service lives
Includes minor maintenance
and rehabilitation

7. 77
LLCP require:
less frequent repair
Rehabilitation
Reconstruction
and therefore contribute to
Improving Highway safety
Mitigating congestion

8. 88
Scope of the scan include the following:
• Materials evaluation and specification procedures for
both virgin and recycled materials
• Design methods of long-life concrete pavements
• Construction practices
• Maintenance practices

9. 99
Issues of Interest
•Materials (cement, coarse & fine aggregates,
admixtures, and supplementary cementations
materials)
•Concrete mixture design
•Pavement thickness design (including geometrics,
spacing, and location of joints)
•Specifications

10. 10
Issues of Interest cont.
• Construction procedures
• Maintenance procedures
• Rapid construction and rehabilitation
techniques
• Performance of jointed plain JPCP, jointed
reinforced JRCP, and continuously reinforced
concrete pavements CRCP.
• Life-cycle costs

11. 11
Pavement Selection Strategies
Long-life concrete pavements:
In every country , "concrete pavement" is
considered synonymous with "long life.“
These countries expect concrete pavements to be
strong and durable, provide service lives of 25, 30,
or more years before rehabilitation or replacement.

12. 12
Technology
Changes

13. 1313
Public and environment:
The public is expressing concerns about
environmental issues such as noise, congestion and
safety.
Environmental issues, especially noise, are
becoming major concerns to the driving public.

14. 14
Public and environment:
In all these countries , there is a heavy emphasis
on traffic safety, noise mitigation, congestion
relief, and use of recycled materials.
In UK , political forces have driven the decision to
reduce noise, (all highway pavements must have
asphaltic surfaces).

15. 15
Scan Objectives
Identify techniques
used in other
countries, and
Implementable in US,
for achieving longer-life
concrete pavements

16. 16
Pavement type selection factors
1. Life-cycle costs
2. Functional class
3. Truck traffic levels
4. Initial cost
5. Environmental issues

17. Pavements optimized for a performance
period in excess of 40 years,
An extended time to first rehabilitation and
minimal interventions for M & R activities.
17

18.  Design catalogs used in
Austria, Belgium &Germany
 Design lives of 30 years
typically used up to 50 years
service expected
 Truck loadings are
heavier than in US,
18

19. Note : Maximum concrete slab thicknesses are a common
feature of the design catalog.
1919
Catalog designs (updated regularly) based on:
1.Theoretical & lab studies
2.Field experiments
3.Performance observations
Pavement DesignPavement Design

20. 20
Pavement DesignPavement Design
In Netherlands & United Kingdom
Mechanistic-empirical design software is used
for project-level design works
The maximum slab thicknesses appear to be
thinner than those designed in US for similar
traffic levels and in many cases heavier trucks.

21. Full-width, full-depth concrete emergency
lanes constructed for future capacity needs
Widened slabs used to reduce concrete
stress and deflection (as in US) and
extending pavement life.
21

22. Fewer tie bars used in longitudinal joints (about half the
number used in US).
Smaller dowel bars (25 mm diameter) used
JCP and CRCP built to same thickness (as in US)
CRCP used for long life in Belgium - technology adopted
from the US
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23. 23
 Sealed and unsealed joints
both perform well
 Bases: dense HMA and CTB;
 5 mm thick Geotextile used to
separate CTB and PCC in Germany
 Foundations are drainable, stable,
protect against frost, and allow
recycling of materials

24. 24
Concrete
HMA
Unbound Base
Type 5
Concrete
HMA Layer
CTB
Type 6
Portion of Austria’s design catalog page showing concrete pavement layer
thicknesses for different traffic loading levels. Motorways are in the S class.

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26. 26

27. 27
1970 -1977
PCC t = 20 cm Steel =
0.85%
1977 -1991
PCC t = 20 cm Steel =
0.67%
1992 -1995
PCC t = 23 cm Steel =
0.72%
Since 1995
PCC t = 23 cm Steel =
Catalog DesignsCatalog Designs
EX: Class B1EX: Class B1
Design lifeDesign life
30 years30 years

28. 28
Emergency Lane
Top lift w/ exposed aggregate
Bottom lift w/ recycled aggregates
10in.
Concrete (combined graded(
HMAC or CTB (with AC/geotextile(
Thick frost protection layer
Subgrade

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30. 30
 Lower-alkali cements and
blended cements used to
mitigate ASR
 SCMs typically not
considered in mixture
proportions
 Attention to aggregate
quality and gradation …
specially for top layer in
two-lift construction

31. 31
Construction and MaterialsConstruction and Materials
 Recycled concrete and
recycled asphalt
pavement used (or
mandated) in lower
layer in two-course
construction
 Some countries use tie
bars coated only in
middle third

32. 32
Construction and MaterialsConstruction and Materials
 Coated dowel bars used
 Intelligent compaction control
used in Austria
 Small-plate proof testing of
granular layers used in some
countries
 Roughness measured with
four-meter straightedge;
excellent smoothness achieved

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ConcreteConcrete
 Freeze-thaw resistant
 Flexural strength (28-days)
Bottom lift ≥ 800 psi
Top lift ≥ 1,000 psi
 Compressive strength (28days)
Bottom lift ≥ 5,000 psi
Top lift ≥ 6,000 psi
 Well graded aggregates – 4
bins
 Two plants
Bottom lift concrete
Top lift concrete

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Max. agg. size typically
used in Europe is (20 mm).
Aggregates
In Netherlands, where
primarily single-lift
construction is done, (32
mm) is the maximum
aggregate size.

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Aggregate BinsAggregate Bins
16to 32 mm 8to 16 mm 4to 8 mm 0to 4 mm

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Interlayer's
In Germany: using (5mm-thick) Geotextile interlayer as a
bond breaker between concrete pavement and cement-
treated base is a recent requirement.
German engineers indicated that the mortar is presumed to
saturate the Geotextile during construction, adding just
enough stiffness to provide support while still acting as a bond
breaker.

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Geotextile Interlayer's
The required concrete thickness for cement-
treated base alternative was increased from
(26 - 27 cm) when the design was changed from
one with a bonded base to one with a base
separated from the slab by a Geotextile.
In the other countries , the typical interlayer
between a concrete slab and a cement-treated
base is a layer of hot-mix asphalt concrete.

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39. 393939
Recycled materials (including concrete and masonry from
demolition) have been used in the base layers in various
countries.
Austria requires the use of Recycled Concrete and Recycled
Asphalt Pavement (RAP) in the lower layer of two-course
concrete (and for base).
Recycled asphalt is allowed up to a maximum of 30 % of the
coarse aggregate in these mixtures.
Recycling

40. 40
Recycling Concept for ConcreteRecycling Concept for Concrete

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Compaction control
In Austria : Intelligent compaction control is used.
The European countries are strict about control of
compaction of all layers.
In some countries load testing of granular layers to
check compaction is conducted with a small plate.

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350 kg/m3 = 590 lb/cy
400kg/m3 = 674 lb/cy , 450 kg/m3 = 758 lb/cy

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Top Lift Concrete Placement
Fresh to fresh on bottom lift concrete

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Placing of the top lift
concrete
Tie-bar placed by hand (right
behind first paver(
Dowels - placed
automatically
Densely compacted bottom
lift – No sinkage

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Two-lift paving
Two-lift construction is
the placement of two
wet-on-wet layers or
bonding wet to dry
layers of concrete, instead
of the homogenous single
layer commonly placed in
concrete paving.

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The bottom layer ( thick & lower quality)
(lower durability or strength), locally available
aggregate or recycled aggregate (such as
recycled asphalt, concrete rubble, or local
aggregate).
The top layer (thin & consists of high-quality
aggregate designed to provide better resistance
to freeze-thaw damage, reduced noise, or
improved friction.
The high-quality surface also increases friction
and reduces noise.

48. Goals of Two-Lift Paving
•Improved Surface Durability
•Improved Safety (friction)
•Reduced Tire/Pavement Noise
•Improved Environment by Recycling
•Improved Pavement Performance

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Low-noise exposed aggregate surfacing:
The solution to concrete pavement noise popular in some
European countries is exposed aggregate surfacing, in which
exceptionally high-quality, durable aggregates are used in the top
course of the concrete slab, and a process of set retardation and
abrasion is used to produce an exposed aggregate surface with
good low-noise properties.
Exposed aggregate is also touted as yielding other benefits,
including good friction and durability. However, favorable noise
levels may also be achieved by specific pavement texturing
techniques.

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Exposed Aggregate Surface
Step 1 - Curing compound + retarder
- water-repellent coefficient > 90 % (first 24 h)
Step 2 - Curing compound (applied after brushing)
- water-repellent coefficient > 85 %

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Minimal surfaceMinimal surface
finishing -finishing -
longitudinallongitudinal
smoothersmoother

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BrushingBrushing
MachineMachine
Exposed aggregate surface
8 or 11 mm max size

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Cement and concrete testing
.
Workability is evaluated using a compaction test, similar to
the ASTM Vibe test.
Ontario and Austria check the air content in hardened
concrete.
In the European countries : alkali-silica reaction (ASR) is
controlled, if detected by preconstruction testing, using
blended cements or cements with low alkali content.

55. 5555
Pavement testing
Countries do not perform quality control testing for noise.
Texture measurements are made, both for end-product and
pavement management system-based data collection.
Only in Germany and Canada MIT-SCAN equipment used
for detecting dowel bar misalignment for both quality
control and quality assurance purposes.

56. 56
Pavement testing
In EU countries A 4-m straightedge is typically
used to measure roughness .
Belgium also uses APL (length profile analyzer) to
measure pavement profile.
The smoothness of pavements was excellent in all
countries .

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MaintenanceMaintenance
 Typically, very little maintenance done on concrete
pavements
 Little if any joint resealing done
 One widely used maintenance technique is a thin
asphalt overlay to correct rutting caused by
studded tires or to mitigate tire-pavement noise.
 Ontario is field-testing precast slab techniques
(similar to US) for rapid repair

58. 58
MaintenanceMaintenance
Only in Canada is diamond
grinding used to improve
smoothness on bare concrete
pavements (Diamond grind
whole surface and perform
full-depth repairs on 1.5% of
surface area at 25 years)
In UK, concrete pavements
overlaid with asphalt to
reduce noise.

59. 5959
Precast slabs for rapid repair
Canada is evaluating the use of U.S developed precast
concrete technology for rapid repair.
Also panels were used for individual slab & multi slab
replacement.

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Overall HighlightsOverall Highlights
 Standard designs
Frost-free foundation & good base
(HMAC/CTB)
 Standard materials
Higher strength concrete than in US
Blended cements more common, less SCMs
Up to 4 bins for concrete aggregate
Exposed aggregate surface – lower noise

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Overall HighlightsOverall Highlights
 Good construction practices
Good ride, even though no ride specs
They use straight-edge testing
Low paste surface (only 1 to 2 mm –
brushed off)
Joint sawing with very little raveling
 Very careful approach to introducing new
features/techniques
Design, materials and construction features need to
be well integrated

64. 64
Thank you
For
Your
Attention