Long Life Epoxy OGPA

Presentation Outline

o An emerging issue

o OECD Summary (Phase 1-3)

o NZ Phase 2 – Lab Work

o NZ Phase 3 – Field trials

An Emerging Issue

An Emerging Issue

• Our Communities want better road surfaces and external environmental agencies are requiring then on major projects as part of consenting conditions.

• NZTA has about 7,000,000 m2 of Open Graded Porous Asphalt (OGPA). Its quiet and smooth with good skid resistance.

• Our RONs programme will double the amount of OGPA.• About 6.4% of the network, but 50% of > 20000 AADT.• Around $20/m2- $30/m2 to replace?• The average life for OGPA is 7.2 years. • Maintenance Budgets are Static and look to remain so.

Are we Agile enough to cope?

Herrington, P.R., Reilly, S., Cook S. 2005. Porous Asphalt Durability Test. Transfund New Zealand Research Report 265. The most common form of distress of aged open graded

porous asphalt (OGPA) is loss of chip from the surface (fretting and ravelling) caused by embrittlement through reaction with atmospheric oxygen.

Resistance to chip loss (the durability of the mix) depends not only on the oxidation resistance of the binder but also on binder film thickness, aggregate grading and percentage of air voids.

OECD Summary

OECD WORKING GROUP ONLONG LIFE PAVEMENT SURFACING

The OECD long-life pavement surfacing project was conducted in three distinct phases:

• Phase 1 (2001-2003): Economic viability of long life wearing courses and identification of candidate materials for long life surfacing;

• Phase 2 (2005-2007): Laboratory elaboration and accelerated load testing of suitable candidate materials.

• Phase 3 (2009-2013): Field tests of the selected materials.

OECD Phase 1 – Innovation in life Surfaces

Phase 1 concluded that long-life pavement surfacing costing around three times that of traditional wearing courses per square metre would find a market for a range of high-traffic roads, depending on: • an expected life of 30 years, • discount rates of 6% or less, • an annual average daily traffic (AADT) of 80,000 or more

with at least 15% of heavy trucks.

• two innovative materials had potential: Epoxy Asphalt and High Performance Cementitious Materials (HPCM).

What is Epoxy Bitumen?

Innovative material developed by Shell in 1960’s for Airfields but mainly been used on difficult Bridge decks.

Commercially available (at least 4 Suppliers Active In Market – Chemco, Colas, ICOPAL, and a Chinese Supplier)

Mixture of specially formulated epoxy resins and ~80-100 bitumen

Two part material Cures to hard rubbery-plastic consistency

Epoxy Bitumen

Epoxy BitumenR

utt

ing

Resi

stan

ce

Hot or Slow Cold or Fast

Chemco Two Part Acid Epoxy

• Part A (used at 14.6% by weight) consists of an epoxy resin formed from epichlorhydrin and bisphenol-A.

• Part B type V (85.4%) consists of a fatty acid curing agent in approximately 70 penetration grade bitumen.

• The product is free from solvents.

Source: Turner-Fairbank Highway Research Center, USA

OECD Phase 2 Summary – Laboratory testing of Epoxy Asphalt

OECD Main findings regarding Epoxy Asphalt

• Stiffer (higher modulus) at service temperatures, with greater load spreading ability.

• More resistant to rutting.• More resistant to low temperature crack initiation.• More resistant to surface abrasion from tyre action,

even after oxidation.• More resistant to fatigue cracking (although the benefits

are less marked at higher strain levels).• Less susceptible to water induced damage.• More resistant to oxidative degradation at ambient

temperatures.

OECD Phase 3 Field Trials

The aims of the field tests were to: • Confirm the performance of the two materials under

real traffic and environmental conditions.• Develop construction methods.• Improve cost estimates.• Optimise material mixes.Thanks to the GFC sites using Epoxy asphalt: • Two 60 m OGPA sections in Christchurch, built 2007• Three 210 m OGPA sections in Christchurch, built 2012.• The United Kingdom: a 110 m SMA section near Truro

(in Cornwall) built 2012.

Increase contractor experience levels.

NZ Phase 2 Laboratory Work

‘Standard’ local OGPA mix design 5.0% binder 20.8 +-0.3% air voids Control : 80/100 penetration bitumen Epoxy : 2 Part Chemco acid curing epoxy

bitumen

Sieve Size(mm)

13.2

9.5 4.75

2.36

0.075

Passing (%)

100 95 32 19 2.5

New Zealand Lab Study Due Diligence

Epoxy Stiffness Gains – not oxidation

0 20 40 60 80 100

Ox ida tion tim e a t 85oC (da ys)

0

2000

4000

6000

8000

10000

12000

Ind

irec

t te

nsi

le m

od

ulu

s at

25

oC

(M

Pa)

EM O G P A O G P A EM O G P A nitrogen a tm osphere O G P A nitrogen a tm osphere

LA Abrasion Test 300 revolutions 30 rpm 10 ºC & 25 ºC % Mass lost

Cantabro Test For Cohesion

Cantabro Test For Cohesion

0 10 20 30 40 50 60 70 80 90

Ox ida tion tim e a t 85oC (da ys)

20

30

40

50

60

70

80M

ass

loss

at

10oC

(%

)

E M O G P A O G P A

NZ Innovation - Dilution Experiments!

Cantabro Test Results (144 years!)

Beam Fatigue

Mix

Initial flexural modulus at

25°C (MPa) (± sd)

Cycles to failure at 25°C and 900 µε

(± sd)

Control800 ± 150 31,900 ± 9700

25% EMOGPA 685 ± 48 40,300 ± 3100

100% EMOGPA 576 ± 64 30,500 ± 7700

IDT Fatigue After 171 Days Oxidation

Mix Cycles to failure at 100 ± 20µε (± 95% confidence limits)

Control 8700 ± 5500

25% EMOGPA 12,600 ± 12,200

50% EMOGPA 10,300 ± 12,300

100% EMOGPA >223,000

Fail Fast, Fail Early Trial at CAPTIF

198,000 wheel passes over 3 weeks

8.2 tonne axle load 45 km/hrAverage of 12.1ºCTyre set at 1.5º angle after

175,000 passes

Epoxy section undamaged

Surface damage to control

CAPTIF Rutting Results

0 20 40 60 80 100 120 140 160 180 200 220

W heel passes (x1000)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Ru

t de

pth

(mm

)C ontro l

E poxy

Figure 6. CAPTIF trial: Progression of rutting.

Table 10. Test section texture depth (mm, replicate measurements)

Section Initial After 198,000 passes

Control 1.43, 1.50, 1.43 1.18, 1.13, 1.08

Epoxy 1.58, 1.76, 1.67 1.36, 1.36, 1.36

Table 9. Test section skid resistance (British Pendulum Number, replicate measurements).

Section Initial After 198,000 passes

Control 65, 64, 64 68, 68, 72

Epoxy 63, 62, 62 56, 59, 58

CAPTIF Skid and Texture Results

NZ Phase 3 Field Trial

Field Trial 1 - State Highway 1 CHCH

Three 60m sections laid – December 2007Standard TNZ P/11 – PA 14 OGPA (20% Void)20% Void Epoxy OGPA30% Void Epoxy OGPA

Site ~ 16,000 vpd heading north – with 6% Heavy Commercial Vehicles

Existing OGPA laid in 1992 being replaced due to fretting

Site checked for structural soundness with FWD

SH 1 Field Trial-December 2007

SH1 Trial Site

SPBI Component Difference (Epoxy – Control)

SH 1LWP Rutting

0 1 2 3 4 5 6 7 80

0.51

1.52

2.53

3.54

4.5

HS14 OGPA Control30% Void Epoxy OGPA20 % Void Epoxy OGPA

Year

Aver

age

LWP

Rutti

ng

SH 1 Skid Resistance

12 13 14 15 16 17 18 19 200

0.10.20.30.40.50.60.7 20 % Void Epoxy

OGPA l30% Void Epoxy OGPA lHS14 OGPA Control L20 % Void Epoxy OGPA r30% Void Epoxy OGPA rHS14 OGPA Control r

Survey No.

Scrim

MSS

C

TRIAL 2 2012 - CSM Materials

3 x 100 Tonne (210m) trial sectionsLaid on Structural AC100% EMOGPA •Prevented pick up and marks of 1st Trial 1.•Lay down Trial invaluable practice50% EMOGPA •Made a bit hot, left dull marks, now ok. 25% EMOGPA •Made and Laid like normal OGPA.

CSM 2 EMOGPA Manufacture

• Manufactured at the Fulton Hogan asphalt plant in Miners Road Christchurch

• Continuous drum plant with a mixing box.• Aggregate is heated to the desired temperature

in a rotating drum before entering a “mixing box” into which bitumen is feed at the desired rate.

• Mixing is achieved by an augur in the box.• The box is not separately heated.

CSM 2 EMOGPA Manufacture

• Part A (the less viscous component) was heated to 85°C in a small tank,

• Part B was decanted from the 200L drums in which it was supplied into a bitumen distributor truck

• Part B maintained at 125°C • Part A was pumped into the main bitumen line

(through which Part B travelled) about 2 m from the mixing box, so that minimal blending would have occurred before entering the box.

•

CSM 2 EMOGPA Manufacture

CSM 2 EMOGPA Manufacture

CSM2 Construction

CSM2 Construction

CSM Cantabro Test Results

0 40

Tim e a t 85C (days )

0

20

40

60

80

100

120

% M

as

s L

os

s i

n C

an

tab

ro t

es

t a

t 1

0C

Co n tro l 2 5 % E p o xy 5 0 % E p o xy 1 0 0 % E p o xy

CSM ITM Results

CSM 2014 Skid Resistance

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 1810

0.1

0.2

0.3

0.4

0.5

0.6

0.7

MSSC LeftMSSC Right

Bridge End

Off ramp

Curved Alignment

CSM 2014 Skid Resistance

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 1810

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Epoxy = 0.6MSSC LeftMSSC Right

Bridge EndBridge End

Off ramp

100% Epoxy

50% Epoxy

25% Epoxy

Curved Alignment

Normal OGPA

Normal OGPA and possibly SMA on bridge

EPOXY OGPA – TRIAL 2 Economics

25% EMOGPA •40 Year Analysis, 6% Discount rate•Extremely good Contract Rate for OGPA•Long Term $6/m2 extra for Epoxy Bitumen•8 Year Life OGPA, 40 Year Life Epoxy•PWOC OPGA 2.4 times Epoxy •11 year Epoxy has same PWOC as OGPA•EI of 4.7, 14 year life for EI of 1

•

Where is it at!

• NO BUDMT and VAC approved• Use on new and existing RONS where

possible• Innovation bedded down in Draft

Specification Available (P/11E)• 1st Contract Tendered and sensible

rates received• Agility being tested with negotiated

rates

The REAL CONCLUSION

We were agile enough to implement a innovative solution to the emerging issue of low noise surfaces and fixed budgets

• Potential reduction of OGPA surfacing maintenance budget to 1/6 of current level.

• Or more good low noise surfaces for the same money

The End