tpf-5(188), evaluation of fiber reinforced composite dowel bars and stainless steel...

providing engineering solut ions to improve pavement performance

TPF-5(188), Evaluation of Fiber Reinforced Composite Dowel Bars

and Stainless Steel Dowel Bars

Research Review Session

October 13, 2011


TPF-5(188) Project Team

• Technical Panel

– Roger Green, Ohio DOT (Chairman)

– Mark Gawedzinski, Illinois DOT

– Andy Gisi, Kansas DOT

– Barry Paye, Wisconsin DOT

– Max Porter, Iowa State University

– Paul Virmani, FHWA TFHRC

• Consultants

– Roger Larson and Kurt Smith, APTech


Project Background

• 1996 – FHWA Test and Evaluation Project 30 (TE-30)

• 1998 – ASCE HITEC Evaluation Plan

• 2002 – FHWA Alternative Dowel Bar Report

• 2003 – HITEC Evaluation Resumed (APTech)

• 2005 – HITEC Draft Interim Report

• 2006 – FHWA Updated TE-30 Technical Summary

• 2008 – TPF-5(188) Initiated


TPF-5(188) Project Tasks and Schedule

Work Task Start End

1. Revise Draft Interim Report 10/17/08 5/1/09

2. Conduct Initial Web Conf 2/25/09 2/25/09

3. Execute Revised Eval Plan 5/1/09 7/1/11

4. Prepare Draft Final Report 1/1/11 6/14/11

5. Host Panel Meeting 6/20/11 6/20/11

6. Prepare Final Report 7/1/11 10/17/11

7. Provide Qtrly Progress Rpts -Each calendar qtr-

8. Conduct Close-out Mtg 10/13/11 10/13/11


TPF-5(188) Evaluation Approach

• Revised Evaluation Plan (April 2009)

– No laboratory testing

Cores not full length specimens

– Field Testing of Alternative Dowel Bars

2009, 2010, and 2011 (Only OH & WI)

FWD testing at FRP, SS, and control joints

Chloride concentrations at top of dowel (ASTM C 1152 – Acid Soluble)


TPF-5(188) Evaluation Approach (cont’d)

Coring – 6 in diameter cores

–FWD testing done before coring

–Cores: outer dowel, 6rd dowel, 8th dowel

–Photographs, visual examination

–Chloride level at top of dowel in core

Desirable versus minimum testing levels

Profile evaluation to get IRI (and faulting?)

– Field evaluation of 15-30+ year old epoxy-coated dowel projects


Chloride Testing (ASTM C 1152) Acid Soluble Residue


Ohio 2 (US 50, Athens) (constructed 1997-1998)

Nominal Design:

10-in JRCP

21-ft Joint Spacing

4-in open-graded base

Dowel Bars:

1.5-in Epoxy

1.5-in FRP

1.5-in SS Tubes

1.5-in SS Clad

71

70

50

Ohio 2

U.S. 50, Athens

Columbus

Athens

77


Current Findings—Ohio 2

• Very low LTE’s on 1.5-in polyester resin FRP

• Intermediate LTE’s on Type 304 solid stainless steel or mortar filled stainless steel tubes and Type 316 stainless steel clad dowels (EB-1998 constr.)

• Relatively good performance of epoxy-coated dowels – major problem debonding of epoxy and rusting under coating but no loss of section


OH 2 EB (Approach Joint)


OH 2 EB (Leave Joint)


OH 2 EB (Epoxy-Coated)


OH 2 EB (Type 304 Stainless Steel Tubes)


OH 2 EB (FRP Polyester Bars)


OH 2 WB (Type 316 Stainless Steel Clad)


Other Ohio Projects

71

70

50

Belmont County

Route 7

(constructed 1983)

1.25-in FRP Bars

Columbus

Athens

77

Wayne County

US 30

(constructed 2005)

Epoxy Dowels

FRP Bars

MMFX Bars

Zinc-Plated Dowels


Current Findings—Other Ohio Projects

• Bel 7 (28 years – 1.25-in vinyl ester FRP and epoxy-coated dowels)

– Lower LTE’s but relatively good performance of FRP (poor LTE’s of full-depth repair with polyester resin FRP)

– Epoxy dowels LTE less than 70% - debonding of epoxy and some section loss

• US 30-Wayne Co. (2005, with DBI)

– Epoxy control, 2 sections, 7 and 6 joints; 3 MMFX joints; 3 zinc plated joints; 1 FRP Composite joint


Investigation of Older Epoxy-Coated Dowel Projects—OH

• OH epoxy-coated dowel performance (14-28yrs)

– No apparent correlation between chloride content and corrosion

– Major problem delamination of epoxy coating and rusting and pitting of steel dowel – some loss of section

– Estimated service life 25-30 years

• Twelve cores of 1.25-in plastic-coated dowels

– Much better condition than epoxy coated after 33 years


Ohio Older Epoxy-Coated Dowels (CUY-176, 14 yrs)


Ohio Older Epoxy-Coated Dowels (BEL-7, 28 yrs)


Ohio Plastic-Coated Dowels

71

70

50

Allen County

Route 81

(constructed 1978)

1.25-in Plastic-Coated Bars

Columbus

Athens

77

Summit County

Route 59

(constructed 1978)

1.25-in Plastic-Coated Bars


Route 81, Allen County

Recovered Dowel Bar

Surface Condition


Route 59, Summit County

Recovered Dowel Bar

Surface Condition


Wisconsin 2 (Hwy 29, Owen) (constructed 1997)

Nominal Design:

11-in JPCP

17-20-18-19 ft Joints

Dense aggregate base

Dowel Bars:

1.5-in Epoxy

1.5-in FRP

1.5-in SS Tubes

1.5-in Solid SS

39

29 94

94 Milwaukee Madison

Abbotsford

Owen

Wisconsin 2

Highway 29 EB,

Owen to Abbotsford


Current Findings—Wisconsin

• WI 2 (12 years)

– Support marginal > 10 mils

– Concrete quality poor at crack face

– FRP (3 types marginal LTEs – 60’s and 70’s) – 2 polyester and 1 vinyl ester

– Hollow Filled Type 304 SS good LTE

– Type 304 solid stainless steel <60% LTE (1 joint)- poor concrete quality at joint

– Epoxy control generally > 85%


WI 2 (LTE vs. Dowel Type)


WI 2 Faulting


Investigation of Older Epoxy-Coated Dowel Projects—WI

• WI epoxy-coated dowel performance (12-33 yrs)

– FWD testing 4 locations

– Coring bit poor quality – Severe deterioration of crack face at joint

– 4 of 44 cores – no dowel(1) or dowel bar end in core (3) – inadequate embedment

– Corrosion not correlated to chloride content

– Extensive to moderate deterioration on projects 19 years or older

– Epoxy coating service life 20-25 years


Chloride Concentration vs. Dowel Deterioration (Wisc)


Wisconsin Older Epoxy-Coated Dowels (USH 18/151, 20 yrs)


Wisconsin Older Epoxy-Coated Dowels (STH 67, 33 yrs)


General Comments

• Very small sample represented (OH and WI)

• Joint deterioration a concern – concrete quality (see TPF-5(224) study)

• Need better documentation of dowel material properties – particularly FRP but also SS

• Other factors [perm base support, joint sealant, construction quality (consolidation, dowel embedment length, early curl/warping stresses, epoxy-coating quality and/or damage during installation)] are also important


Summary and Recommendations

• Recommended testing approach involving

FWD testing and coring of joints appears

good. However, chloride content testing did

not correlate with corrosion observed on older

projects. Add coating thickness and knife-

coating adhesion test (see TRR 2220)


Summary and Recommendations (cont’d)

• LTE performance of 1.5-in polyester resin and

e-glass not acceptable. Larger diameter vinyl

ester resin and ECR-glass needed - Suggest

1.75-in for strong base support (unbonded

concrete overlays) and service life > 50 years.

Have AASHTO/ACI Materials Group develop

guide spec (Mateen Dowel spec available).

• Evaluation of Type 304 (solid or mortar filled

tubes) and 316 Stainless Steel clad dowels

inconclusive due to short evaluation period.


Summary and Recommendations (cont’d)

• Service life of epoxy coating on mild steel dowels appears to be in the 25-30 year range. For longer life pavements more durable coating required.

• Plastic-coated dowels (2 projects) showed better performance than epoxy-coated dowels

• Due to small sample size and confounding factors, recommendations are based on a subjective evaluation of test results and other published literature


Draft Implementation Plan

• Evaluate long-term corrosion of epoxy-coated dowels (coring and FWD) in each state to determine corrosion protection performance.

• Use vinyl ester (not polyester) for FRP dowels – Have AASHTO/ACI Materials Group develop generic spec for long-life FRP dowels.

• Improve quality control checks of epoxy-coated dowels if continued to be used.

• Consider adopting plastic-coated dowels as standard on new projects.


Other Relevant Research

• Iowa – Field and Lab studies • Caltrans – Lab and HVS • West Virginia – Lab and Field

– 2009 Final Report • Mn/DOT Lab and Field • Canada Lab and Field – Quebec Report 2011

– 10 year plan to evaluate use of fiber composite materials in reinforcing bars and dowels nearing completion

• CPTP Tech Briefs on Long-Life Pavements and FRP Bars in CRCP


TPF-5(188)

• Final Report - Evaluation of Alternative Dowel Bar Materials and Coatings

• Data and related reports CD?

• Questions????

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