087 active crack control of continuously reinforced concrete pavements through partial surface...

Delft University of Technology

Active Crack Control of Continuously Reinforced Concrete Pavements Through Partial Surface Notches-Field Investigation

Dongya REN, PhD Students

Promotor: Prof.dr.ir. S.M.J.G. Erkens

Copromotor: Ir. L.J.M. Houben

Road Engineering, CEG, TU Delft

2 Investigation of Early Age Crack pattern in Continuously Reinforced Concrete Pavements

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Why is CRCP used?

Antwerp Ring 1,CRCP, rebuilt in 2004

200,000 vehicles per day

• Low maintenance

• Heavy Traffic

• Smoothness

• Longer lasting (Design life 40 years)

• Less costly (Life cycle cost analysis)


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• Motorway E40 Brussels- Liege

• Built in 1971

• Excellent performance!

• E313, Herentals-Antwerp • Rebuilt in 2012

• Active crack control


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Concept 1

1970-1981

• 0.75%(φ18mm@150mm), H=200mm, Asphalt interlayer

• Unfavorable crack pattern ( L= 0.4~0.6 m about 18 years, cluster of closely spaced cracks)

• Some sections still behave quite well after 40 years of services

Concept 2

1981-1995

• 0.67%(φ16mm@150mm), H=200mm, No Asphalt interlayer

• Ideal crack pattern ( L= 1.4~2.4m, 70% within 0.8-0.3m)

• Punchout problems due to the erosion of the base layer

Concept 3

1995-Now

• 0.75%(φ16mm@150mm), H=230-250mm, Asphalt interlayer

• L is about 1.0m about 2 years with clusters of closely spaced crack(few data available)

• Behave perfectly

CRCP Design Concept Change in Belgium


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Characteristics of crack spacing of concept 3 in Belgium

S. Holler (2009) E40(Walshoutem), E34(Antwepen) F. Feys (2010) E40(Affigem), N255 J. Van. Avermaet (2010) E17(Kruishouterm) D. Ren (2011,2012) E17(De Pinte), E313(Active crack control)


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Problem

• Non-uniform crack patterns are detrimental and common

• They can lead to spalling and punchout

Punchouts


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A12 Design features of A12 • Reconstructed in 1998

• Porous Asphalt + CRCP

• 40 Years Design Life

• 100,000 ADT

• 5 cm Porous Asphalt • 25 cm CRCP, 0.7% steel • 6 cm dense Asphalt base • 25 cm cement bound

recycled asphalt sub-base

A5, A12, A50, A59, A73/74


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A50


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CRCP in Netherlands

Schematic view of crack map in CRCP on November 9, 2013, on A50. The red line represents a crack with reflective crack, the blue line represents a crack without reflective crack.

0 5 10 15 20 25 30 35 40 45 50

50 55 60 65 70 75 80 85 90 95 100

R R R R R R R R

R R R R RRR


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Active Crack Control

Tape Insertion

Partial surface notches

Transverse surface notches


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Active Crack Control

0.4 m

1.2 m

• saw cut length : 400 mm • saw cut interval: 1200mm • saw cut depth: 30 mm &60 mm • Saw cut time: Immediately after the surface treatment but for sure within 24 hours after placement

6 cm


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Monitoring Program

• Concrete temperature

• Concrete properties • Crack width

• Crack movement

• Crack spacing

Passive Crack Control Test section E17 2.0 km long test section 6 surveys Active Crack Control Test section E313 1.6 km long test section 5 surveys


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Effectiveness of crack inducer

Percentage of Cracks Initiated at the Notches


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Crack spacing

Comparison of Cumulative crack spacing distribution between E17 and E313

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.0 0.6 1.2 1.8 2.4 3.0 3.6 4.2 4.8 5.4 6.0

Cu

mu

lati

ve

per

cen

tag

e

Crack spacing (m)

E313- 60 mm-12 months

E313-30 mm- 14 months

E17- 0.75%- 12 months

27.6%

66.0%

74.3%

Desirable Crack Spacing range: 0.6 m~2.4 m


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Crack spacing

Average crack spacing for five consecutive cracks

Uniformer Better Crack Spacing Distribution


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Cluster cracks

Cluster cracking probability

A typical section with clusters of closely spaced cracks in E17

(Conventional CRCP section)


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Crack Pattern

Straighter

E17

E313

E313


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Crack width measurement


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Crack Width

60 mm depth saw cut section

10 months (03-04-2013)

4.2 ℃

Crack width measured on the surface in

E313

60 mm depth saw cut section

2 days (13-09-2012)

25.0 ℃


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Crack Width

Crack Width on the Pavement Surface Measured by Microscope

Crack Width Limitation of CRCP in the Netherlands: 0.4 mm


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Summary of findings and Conclusions

• A CRCP with an active crack control system outperform CRCP with passive

crack control because of crack pattern are more uniform, straighter.

• CRCP with 6 cm depth saw cut perform much better than the one with 3 cm

depth saw cut.

• All test sections meet the crack width requirement.


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Thanks for your attentions

Questions?

087 active crack control of continuously reinforced concrete pavements through partial surface...

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