Presented at the XXIV Nordic Concrete Research Symposium in Stockholm, August 17-19, 2022.

1. Rapid Repair of Concrete Pavement Using
Precast Concrete Technology
Doctoral student: Saima Yaqoob
Main supervisor: Johan Silfwerbrand
KTH Royal Institute of Technology, Stockholm, Sweden
24th NCR Symposium, Stockholm, Aug. 17, 2022
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2. Content of the PhD Project
I. Literature survey (completed)
II. Numerical analysis (on-going)
III. Full-scale tests (planned for 2023)
Sponsored by Trafikverket (Swedish Transport
Administration)
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3. • Concrete pavements are suitable for high
traffic volumes.
• Several other advantages: Durability, fire
resistance, resistance against frost heave,
evenness, aesthetic etc.
• Concrete pavements are long-lasting but if
damage appears they need rapid repair to
avoid traffic congestion.
Benefits of concrete pavement
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4. • Jointed plain concrete pavement (JPCP)
o JPCP is designed so that the concrete slab expands or contracts
at joints.
o Dowels bars are used across the transverse joints to transfer the
load between the adjacent slabs.
o JPCP is most common in Sweden.
• Jointed reinforced concrete pavements (JRCP)
• Continuously reinforced concrete pavements (CRCP)
Types of concrete pavements
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5. • With precast concrete technology,
rehabilitation of concrete pavement can be
done during short time work windows.
Precast concrete technology
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6. • Promising experience with precast concrete
technology to rehabilitate concrete
pavements exists in USA.
• The aim is to adopt the US experience to
Swedish conditions, i.e., climate, weather,
geology, studded tire traffic, views on
environmental & economic issues, rules &
traditions for procurement etc.
Aim of the research
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7. Precast concrete slabs
 American experience
since 2001.
 Presented at the
workshop ”Achieving
High-Quality Precast
Concrete Pavement
Installations” in San
Antonio, TX, USA, in
August 2016.
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8. Experiences
 Minor American projects in the 1960s & 1970s.
 Should exist early projects also in Russia & Japan.
 Interest from FHWA (USA) since 1990s.
 New start in USA in 2001 (roads, airfields).
 Since then, 80 projects in 15 states with 60
contractors involved.
 Total: 50 lane-km (32 lane-miles)
Tayabji, 2016
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9. Precast concrete slabs
Repair Panels
Conventional Jointed PCP System
Tayabji, 2016
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10. Principle repair
Existing Slab Existing Slab
Existing Base
Precast Panel
Prepared bedding (Granular or
flowable concrete)
Tayabji, 2016
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11. Joints & dowels 1 (2)
 Two main alternatives:
1. Using slots at the panel top surface (several
variations)
2. Using slots at the panel bottom (one patented
system)
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12. Joints & dowels 2 (2)
Tayabji, 2016
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13. Production of precast concrete
panels
Tayabji, 2016
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14. Success factors
 Create full contact between the precast concrete
slab & well produced underlying layer.
 Make certain that the load-transferring dowels in
the transverse joints are completely surrounded
by grout.
 Produce a finished concrete surface on an even
and correctly produced roadbase layer.
 Construct a finished concrete surface with correct
slope.
NPCA, 2016
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15. NJ I-295 (2008) – Repair panels
 Process:
 Cutting the edges of the repair in advance.
 Repair night: Remove damaged panel, prepare the base, drill
dowel holes in existing panels, install dowels, install new
panels.
 Next night: Fill the dowel holes with grout, inject grout under
the new panel.
Tayabji, 2016
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16. NJ I-295 (2008)
NEXT
NIGHT

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FIRTST NIGHT
Tayabji, 2016

17. Load transfer efficiency in JPCP is dependent on the dowels,
therefore numerical analysis will be conducted to analyse the
stress concentration around the dowel bars at three different
positions.
• Position 1: Dowels at the top- height of concrete slab
• Position 2: Dowels at the mid-height of concrete slab
• Position 3: Dowels at the bottom-height of concrete slab
Numerical analysis
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18. The field test will be conducted to…
• To analyse the total lane closure time of the
rehabilitated pavement using precast concrete
slab.
• To analyse the structural performance of
precast concrete slab according to Swedish
conditions.
• To find out the possible cost for the concrete
pavement rehabilitation using precast concrete
panels.
Tests planned for spring 2023 in co-operation
with the City of Stockholm and the Swedish
producer of precast concrete products Abetong
focusing on bus stops.
Field test
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