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SILICONE JOINT SEAL PERFORMANCE

Report to National Executive ASCP

By Todd Myers 9 September, 2012 Disclaimer: The views represented in this report are those of the author and do not necessarily represent those of ASCP Executive nor the companies that responded to the questionnaire on joint sealing issues on recent projects. All data supplied via the questionnaire with respect to previous project performance has been supplied by the individual organisations that completed the work and has not been verified and all assessments on percentage of joints with issues are subjective at best.

REPORT TO NATIONAL EXECUTIVE ASCP

SILICONE JOINT SEAL FAILURES

INDEX

1. EXECUTIVE SUMMARY ...................................................................................................... 1

2. BACKGROUND ................................................................................................................... 2

3. CUTTING AND SEALING HISTORY IN NSW ...................................................................... 3

4. DATA COLLECTION RECENT PROJECTS ........................................................................ 5

5. ANALYSIS OF COLLECTED DATA .................................................................................... 6

6. SILICONE PRODUCTS ....................................................................................................... 9

7. USA PRACTICES .............................................................................................................. 11 8. CONTRIBUTING FACTORS .............................................................................................. 14

APPENDIX A – Sample Blank Questionaire APPENDIX B – Summary Maps Pacific & Hume Highways Showing Projects since 2006 APPENDIX C – Spread sheet Summary all Collected Data APPENDIX D – Letter from Dow Corning 21st May 2012. APPENDIX E – Letter from Dow Corning 18th June 2012.



Page 1

1. EXECUTIVE SUMMARY

After finding a project with poor performing silicone sealant in transverse joints a project questionnaire was developed and sent out the members of the Executive of the ASCP.

The issue found involves the silicone seal dropping within the joint due to adhesion failure. It first appears in the wheel path of the slow lane, but has been seen also in the fast lane. In most cases the issue has not presented until after 9- 15 months after opening, and is not visible at normal driving speed.

A total of 11 projects were identified as have been paved during the period of 2006 till current. Of these one is yet to be inspected and one is yet to be opened to traffic and thus excluded from the analysis. The 9 projects reviewed cover both the Pacific and Hume Highways.

Of the 9 projects included 6 have greater than 10% of affected joints, with 4 of these greater than 20%.

The 4 worst affected projects are all located on the Pacific Highway and have average rainfall between 1400mm and 2200mm. The 2 best performing projects are located on the Hume Highway and both have less than 500m of average rainfall per year. One of these currently shows no signs of distress while the other has < 1%.

This report does not make any recommendations but discusses possible contributing factors that may lead to a possible solution.



Page 2

2. BACKGROUND

During a routine inspection of the Coopernook to Herons Creek Alliance Project (C2HC) (Thiess) some silicone seal issues were identified. The project had been open to traffic for over 18 months when the issue was first identified. After a few calls to other major contractors, it was found that a similar issue had also occurred at the Ballina Bypass Alliance Project (BBA) (Leighton’s), again the project had been open to traffic for only about 12 months.

In both projects the issue was very similar, in that the slow lane wheel path was where the issue appeared first, with the silicone failing in adhesion to the edge of the saw cut. The silicone is then dropping down within the saw cut.

A detailed inspection was undertaken on the C2HC project by the site team. There appeared to be no pattern to the location of the joints with issues, except that they were often in the wheel path of the slow lane but were not exclusively at that location. While the issue appears to be spread along the entire length of the project geographically, there are many locations where 10-20 adjacent joints show no signs of distress and then the next 2- 5 joints all show issues of adhesion failure.

Figure 1.

An example of a transverse joint adhesion failure

Figure 2.

Close-up view of Silicone adhesion failure



Page 3

3. CUTTING AND SEALING HISTORY IN NSW

The practice of cutting and sealing of PCP roads in NSW has been undertaken since the introduction of concrete roads in the late 1970’s. During this period of 40 years there have been only a few changes to the standard practices used.

There are 3 main processes involved with cutting and sealing, these include;

• Cutting Method – Wet Cutting or Early Entry Cutting

• Cut Type- Two Cut method or Single Cut Method

• Seal Type – Preformed Seal or Silicone Seal

Figure 3 below shows an approximate timeline when the 3 processes described above where changed throughout the period 1980- 2012. While there was some period of overlap within the 3 process, the change-over date as shown below would represent the approximate time period when the majority of the industry within NSW change from one method to the other for each process.

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

2006

2008

2010

2012

History of Cutting & Sealing Methods in NSW

Seal Type

Cut Type

Wet Cutting Early Entry

Two Cut Method Single Cut Method

Preformed Seals Silicone Seals

Cut Method

Figure 3. History Cutting & Sealing Methods in NSW

NSW has had good experience with the use of silicone sealants over the past 20+ years. Many projects are well in excess of 10-15 years and have experienced little or no silicone failures. An example of this would be Bulahdelah Deviation build under a DCM contract form when after the end of the 10 year maintenance period no sealant joint repairs were identified during the detailed handover inspection process. This project is approaching 14 years old and the silicone is still performing very well. There are many other projects of similar age that are performing just as well and thus clearly shows that the process used on these projects were in fact sound.



Page 4

The saw cut widths and ratios used today are still the same as that used for the past 20-30 years.

Figure 3 shows that there was has been really only 2 major changes (since introduction of Silicone seals in about 1988) in the saw cutting and sealing process in the past 30 years, these being;

1. The introduction of the single cut saw method (to replace the two cut method). This was progressively used from about 1992.

2. The introduction of the early entry cut sawing replacing the conventional wet sawing process.

The single cut method of sawing the transverse P8 joint is as the name suggests a single cut sawing method where the full design width of the cut is made as soon as the cutting is able to be undertaken with excessive spalling. The two-step cutting process uses an initial narrow (3mm) cut as soon as the pavement is able to be cut (8-16hrs are placing) and then it is later widened to the design with of 7mm -0/+3 after about 4-5 days.

The benefit of the single wet cut method as put forward by Dave Rees the Managing Director of Concut Pty Ltd( Concut were up until about 2005 one of the major subcontractor cutting organisations in NSW) was the micro texture left behind when completing the saw cut after only 6-10 hrs. The water used during the sawing process, with the concrete at a very early age allowed a ‘sandpaper’ like effect on the inside of the saw cut, whereas if the concrete was cut again (two cut method) then the resulting finish was a smooth finish which was not a desirable finish for the silicone to adhere onto.

The early entry sawing was first undertaken in NSW in about 2005-6 and has been used basically exclusively since by all contractors and subcontracts cutting organisations. This new cutting method allows early cutting of the pavement (without excessive spalling) thus reducing the risk of unplanned cracks in the pavement.

The early entry cut process has been used in the US for many years and examples have been found of articles on the internet as far back as 20 years ago showing early entry cutting process, thus it is not new. The main difference between early entry sawing and conventional wet cutting is the early entry sawing is completed dry and a powder produced, rather than a wet slurry. The other difference is the early entry cutting process uses a up cut saw rather than a down cut as per a wet cutting saw.

The US Federal Highways Administration (FHA) (1) reported in a technical brief in June 2007 that 25 of the 33 respondent highway organisations with the US allowed early entry sawing. Of these only 3 have separate specifications for saw using the early entry method which allow shallower depths of cuts when using the early entry cutting method.



Page 5

4. DATA COLLECTION RECENT PROJECTS

After identification that the issue was occurring on multiple projects it was decided that the need existed to collect information from recent projects to try and establish the extent of the issue throughout NSW. A project information sheet was developed and circulated to members of the Executive to be completed on behalf of their respective organisations for all projects paved after 2005.

The project information sheet collected data in the following categories;

• Project Details

• Pavement Details

• Cutting & Sealing Details

• Visible Defects

• Possible Causes

In total data was collected on 11 projects although no inspection has yet been undertaken of Brunswick Heads project and also Kempsey Bypass Alliance project is yet to be opened to traffic and thus has been excluded from the analysis.

A blank copy of the questionnaire is included as Appendix A. All data was supplied direct from the contractor that completed the project, being Abigroup, Leighton Contractors and Thiess.

The nine projects during paved during the period of 2006 thru to 2011 encompass over 250carriageway km’s of PCP pavement. There are 4 projects on the Pacific Highway and 5 on the Hume Highway, They span from Ballina Bypass in the north to the Southern Hume Alliance project in the south of the state.

A map of both the Pacific Highway and Hume Highways has been included as Appendix B showing each of the projects along the respective highways. The length of each project in question along with the dates of the mainline paving (MLP) as well as the percentage of visible joints affected is included on each map.



Page 6

5. ANALYSIS OF COLLECTED DATA

From the completed questionnaires the data was transferred into a spread sheet for analysis. A full copy of all data collected in spread sheet format is included as Appendix C.

It should be noted that all estimated % of joints affected are very subjective and in some cases a full project review has not been undertaken and values shown in the analysis are purely taken from roadside visual observations after stopping at several locations within a project.

While no conclusive outcome can be drawn from the data there is some interesting points that are derived from the data.

• 7 of 9 projects have >1% of affected joints

• 6 of 9 projects have =>10% of affected joints

• 4 of 9 projects have >20% of affected joints

• All 4 of the projects with >20% affected joints are on the Pacific Highway

• All 4 of the projects with >20% affected joints recorded > 1000mm/yr rainfall

• All 4 of the projects with >20% affected joints are within 10kms from the ocean

• All projects were sealed with Dow Corning 888 Silicone.

• All projects were cut using early entry sawing.

• All projects were cut using the Single cut method for the P8 joint

• All projects used the same cleaning methods prior to silicone sealing

• A total of 4 different sub-contractors undertook the cutting & sealing.

A series of graphs highlighting some of these issues follows;

Figure 4.

Summary Recent

Projects with Estimated %

Joints Affected and

Average Yearly Rainfall

Figure 4 above clearly shows that the 4 worse affected projects are located in wet areas where the annual average rainfall is greater than 1000mm/year



Page 7

Figure 5.

Summary Recent Projects with

Estimated % Joints Affected and

Distance from Sea

Figure 5 above shows the 4 worst affected projects are all located within close proximity to the coastline, in fact they are all within 10km as the crow flies to the sea. As the coastal areas on NSW receive a much higher average rainfall than inland areas Figure 4 and 5 highlight this fact.

Figure 6.

Summary Recent Projects with

Estimated % Joints Affected Project Age

(Years)

Figure 6 above shows the age of the project on the secondary axis. One important fact that was gathered thru the questionnaire is that the issue tends to appear initially within the first 1- 2 years after opening and thus projects that are beyond this period and currently do not exhibit any signs of the issue (eg Coolac) may be unaffected. On the other side of the coin, projects that have not reached this age ie less than 2 years old may not yet be showing the true performance as yet.



Page 8

A Summary of the common aspects of the Silicone Joint Issue;

• Joint sealant starts to drop down into the saw cut joints.(Adhesion Failure) • The issue has generally started under the wheel paths of the slow lane. It seems to

propagate outwards from there. • The issue is not noticeable when traveling on the highway at highway speeds. • The issue has tends to appear 12-18 months after the pavement has been opened to

traffic. • The issue is mainly in the transverse joints but has also been observed in longitudinal

joints. • Where the issue has been noticed the silicone does have a darker appearance. • Some joints that visually appear ok are found to be affected when the silicone is push

down by hand pressure. • The issue is not isolated to a specific date of installation. It seems to be random,

although in some areas generally worse than others. • Issue does not seem to be prevalent in the Shoulder although was noticed on very

rare occasions.



Page 9

6. SILICONE PRODUCTS

All of the projects within this report were sealed with Dow Corning 888 Silicone from the USA. A locally made product is available from Parchem, although research has shown that the product is widely used on bridge parapet sealing and expansion joints, as well as minor seal repairs as it is often supplied in “sausages” for use in hand applications. The last major road pavement project to use the Parchem Roadseal was Karuah to Bulahdelah section 1 completed by Baulderstone’s in 2005-2006.

Tabl1 1 below lists both the Dow Corning 888 and the Parchem Roadseal as well as another major supplier (Crafco) from the US for comparison purposes. The table list the relevant manufactures recommendations with respect to joint preparation and sealing restrictions.

Company Dow Corning Parchem Crafco Product Name 888 Roadseal Roadsaver

Origin USA NSW, Australia Arizona, USA Install Brochure 40 Pages 4 Pages 2 Pages

Min Concrete Age

7 days in good conditions add 1 day

extra for each inclement day.

14 days 7 days

Water Cleaning Yes High pressure Yes High pressure. Yes, flushing Sandblasting Joints Yes 2 Passes N/A Yes

Compressed Air Blown Yes min 90 psi Yes Yes min 90 psi Non - recommended

Practices Grinding or wire-

brushing N/A N/A

Time Restrictions N/A Min 16 hrs drying after air blasting

Cleaning must occur same day as sealing

Cleanliness test No residual cement dust on finger after

rubbing N/A Rub finger any dust,

further cleaning

Field Adhesion Test Yes N/A N/A

Primer Not required in most applications

Required if weather conditions not conducive

to drying N/A

Backer Rod Yes, Closed Cell Yes, Closed Cell Yes, Closed Cell Tooling Required Yes Yes, within 10mins Yes Minimum Recess 9.35mm 5mm 6mm

Recommended Min Joint Width

9.35mm, Can be 6mm 6mm 3mm

Optimum Width/Depth Ratio 2:1 2:1 2:1

Seal Depth (Restrictions) N/A Min 10mm Max 12mm

Minimum Air Temp 4 Deg C & rising 5 Deg C 4 Deg C

Joints Must Be Clean, dry and frost

free, free of standing water

Clean, dry free from concrete slurry, oil dirt or

loose material, form release or curing

compound

Completely Clean and Dry



Page 10

A comparison of the important aspects as recommended by each supplier highlights some close consistency as well as some major differences.

Common Recommendations

• High Pressure Washing required by all

• Both US products recommend sand blasting of the joints

• High pressure air blasting is required by all

• Tooling is required by all

• Optimum Width to Depth ratio 2:1

• Minimum Temp for seal 4-5 Deg C

Differential Recommendations;

• Parchem require 14 days minimum concrete age, both US products minimum 7 days

• Parchem are silent on sand blasting of the joints

• Parchem have a recommended 10mm min depth whereas Crafco has a maximum 12mm sealant depth. These two suppliers appear to have recommendations that are in direct contradiction of each other.



Page 11

7. USA PRACTICES

The US builds many hundreds of miles of concrete pavement each year. The specification they use for concrete pavement, sawing and sealing varies from states to state.

Gerald F Voigt reported (2) in 1997 that 52% of US states used silicone sealants while 25% used hot poured seals and 22% used preformed compression seals. While there are many articles on performance of silicone seal there is one common thread within every article, that being the preparation of the joint reservoir is of utmost importance with respect to being clean, dry and silicone applied to the correct ratio.

The one aspect that does appear similar between various US states is the specifications for saw and sealing is the preparation of the cut joint. Two examples are given below;

• CALTRANS (3)

o Saw joint using power driven saw

o Immediately wash joints (max pressure100psi)

o Install joint filler to keep moisture in the joint (min 72hrs)

o If joint filler not used additional curing compound must be applied to inside of saw cut.

o A minimum 7 days after paving and not more than 4 hours before sealing use dry sandblasting to clean wall of the joints. Minimum 2 passes with max nozzle dia ¼”

o Vacuum clean the joint reservoir of all material

o Remove any surface moisture with compressed air (water and oil free)

o Install backer rod

o Apply sealant (air temp above 40 degrees F/ 4.5 degrees Celsius)

• IDAHO (4)

o Install stress relieving cut as soon as practicable.

o A minimum 72 hours after placing joint reservoir sawing to be undertaken

o Immediately wash joints by jet washing

o Not more than 1 hour before sealing use dry sandblasting to clean wall of the joints.

o Remove all loose materials with compressed air (100psi) (water and oil free)

o Install backer rod

o Apply sealant (air temp above 50 degrees F/ 10 degrees Celsius)

o Technical representative from sealant manufacturer must be on site for a minimum of two days during initial sealing works

Although slightly different the two common items are the water jet washing and the grit (sand) blasting of the joints. Both of these two items appear in most US specifications read.



Page 12

This is highlights a major departure as compared to NSW specifications which states that grit blasting is not allowed. It is not known when this clause was introduced in NSW specifications but it is likely to have been in place for over 20 years.

The Seal no Seal group(5) in the US has funded a research project by WJE Associates of Illinois for “Joint Reservoir Moisture and Contamination Test Procedure” and is due for completion in the 3rd quarter of 2012. While every specification for silicone joint seals uses the words ‘clean and dry’ this appears to be the first time that a procedure has been developed to try and define what ‘clean and dry’ actually means.

The study is working of 3 aspects of the joint reservoir, being;

1. Cleanliness Test

2. Moisture Test

3. Wipe Test

Figure 6

Cleanliness Test

A length of electrical tape is inserted into the prepared saw cut with a tongue depressor with the sticky side outwards and pushed firmly against the sides of the cut and then removed and compared back to the reference photos.

Figure 7

Moisture Test

A length moisture sensitive paper is inserted into the saw cut using a tongue depressor pushed firmly against the sides and base of the cut and then removed and compared back to the reference photos.

Figure 8

Wipe test

A length 2” wide 100% cotton black cloth is inserted into the saw cut using a tongue depressor pushed firmly against the sides and base of the cut and then removed and compared back to the reference photos.



Page 13

While the study is not yet complete it does provide some insight in the steps that may be appropriate for determining what degree of cleanliness is required before joint sealing operations can commence.



Page 14

8. CONTRIBUTING FACTORS

While it is widely recognised that the (lack of) cleanliness and dryness of a joint is the major factor in silicone sealant suffering from adhesion failure although there appears to be no accepted method of determining these two aspects of a sawn joint.

Experience has shown that when trying to solve a new issue that often it will not have a single answer but is likely to be a combination of several factors with varying levels of influence. If the starts align on several of the aspects then ‘failure’ may occur while if only ‘some’ of the issues occur then the product performs as per expectations.

The following factors discussed below are considered to be potential contributors to the issue but no weighting is able to be given to each individually.

8.1 Environmental Factors

From the data shown in Figure 4 it is clear that projects with higher average rainfall have been experiencing a higher percentage of joints with the adhesion failures, although there are also some projects such as the Hume Highway Woomargama Alliance located in an area with only 450mm of rainfall on average already showing an unacceptable percentage of joint issues at a very young ago of only 8-9 months.

While it is believed that all contractors are complying with the minimum 7 day age of the concrete prior to sealing the issue remains as to how is the pavement being assessed as to when it is dry enough after rainfall events as to when it is acceptable to commence sealing. The standard practice would currently be leaving this decision with the sawing and sealing subcontractor. What steps or processes do they have in place? It is likely that a visual assessment based on ‘experience’ is the only process in play.

The extent of this environmental factor (high rainfall) being the major factor in this issue is undefinable and the proposition that it is the sole cause is unlikely. There have been many projects completed in the late 1990 and early 2000 in very high rainfall areas such as Bulahdelah Deviation, Raymond Terrace Bypass and Karuah Bypass which appear to be performing without any evidence of a problem with the joint seals.

8.2 Joint Seal Widths

While all of the 3 suppliers listed in Table 1 show an optimum width to depth ratio of 2:1 for the sealant, the standard in NSW for P8 transverse joints has been unchanged to any major extent for nearly 20 years at 1:1. Apart from the past 4-5 years the current specification sealant ratio has been performing well and thus it is very unlikely to have contributed to any effect on the current issue.

8.3 Sealant Products Used

All projects assessed as part of this report show that Dow Corning 888 was the silicone used on the project. This same product from the US has been used for over 20 years in NSW. After discussions with other paving contractors in the US there has been no recent issues with the performance of this product in similar applications. The only potential issue that could occur is if the product is outside the use by date which is 12 months after its manufacture date. This is monitored on each project and the wide spread but intermittent pattern to the issue is not reflective of a ‘bad’ batch of product.



Page 15

8.4 Cleaning Methods

All of the projects completing the questionnaire reported that the cleaning process includes high pressure air blasting and wire brushing of the saw cut. While all 3 sealant suppliers as detailed in Table 1 all recommend high pressure water blasting and the 2 US manufactures also recommend sand blasting on the joints.

This discrepancy was raised with the Dow Corning representative in Australia, Mr Vic Ostic and he advised in a letter to Supercut in May 2012 that high pressure air blasting is sufficient to remove joint contamination and that water and or sand blasting is not required. A copy of this letter is included as Appendix D. Supercut have also verbally advised that Vic has informed them that the reference to water blasting in the Dow Corning install documentation was a ‘hang-over’ from conventional wet cutting process of the past.

The current RMS specification specifically advises that the use of sand or grit blasting is NOT allowed.

8.5 Cutting Methods

The method of cutting the concrete pavements using early entry cutting process is a significant change from the standard practice of wet sawing. This does necessarily mean that this is a change for the worse but the timing of the introduction of the sawing method cannot be overlooked when looking for a contributing factor in this issue. The timeline detailed in Figure 3 shows the introduction of the early entry cutting process commenced around 2006, the same time as these joint sealant issues appear to have surfaced.

Could it be the cutting process that has contributed to the issue or some sort of consequential effect of the cutting process? If this cutting process is a contributing factor then why has not similar issue been observed overseas as early entry cutting has been used since about 1998 in the US? The answer may be explained by the different cleaning process used throughout the US as compared in here in NSW.

Two example specifications from the US are detailed in section 6 of this report and both mandate that water blasting followed by grit (sand) blasting followed by air blasting as the full cleaning process.

One hypotheses put forward by Supercut/Dow Corning is that the early entry saw blade is depositing some of the curing compound from the surface onto the sides of the saw cut. Some laboratory testing undertaken by Dow Corning US found that if the side of the cut is contaminated with curing compound then adhesion of the 888 was found to be poor and unsatisfactory. This is not unexpected as the issue of line marking peeling off roadways cured with hydrocarbon based curing compounds is quite common in NSW unless it is fully removed.

The one missing fact in this hypotheses is that no evidence has been put forward of any actual contamination being found on a completed saw cut. This does not mean it does not exist, but is yet to be reported.

Dow Corning have since superseded there letter dated 21 May 2012 (refer Appendix D) re Dry Cutting Procedure and issued a new procedure in a letter dated 16th June 2012 (Refer Appendix E) which now includes a step to ‘mechanically abraded the joints with a wire wheel or equivalent to ensure all impurities are removed’

This appears to be in direct contradiction to the Dow Corning Installation Guide(6) on page 15 specifically states ‘Other techniques such as grinding or wire brushing are not recommended’



Page 16

The question that needs to be asked is that, will Dow Corning stand behind its warranty of the product, if installation is undertaken in accordance with this latest ‘Dry Cutting Procedure’? The answer may lie in fact that they do not appear any longer offer any warranty on the product at all even if all recommendations are followed.

8.6 Workmanship & Training

The saw cutting and sealing process is a heavy semi skilled labour orientated operation, and thus open to the normal compliancy associated with all repetitive operations.

The importance of the cleaning process for each and every cut cannot be lost in the boredom’ of a long day in the sun.

Has the current issue been discussed and tool boxed with the supervisors and crews at the front line of the sealing operations?

Have we become complacent in this part of the pavement operation, or loss focus on this part while concentrating management time on the placing and compacting of the pavement?

Is there any formal or informal training given to the crews cleaning and placing the silicone sealants? As this has been predominately an area where subcontractors have been used in the past and they are ‘specialist’ at their chosen activities and thus they have tended to be left to their own devices, with little or minimal supervision.

Employing some or all of the checking process as described in section 6 of this report as per the current trial being sponsored by the Seal no Seal group may be a small but very positive step forward.



Page 17

References

(1) US Federal Highways Administration Tech Brief Use of Early Ag sawing in Portland Cement Concrete Pavements

(2) Pavement Crack and Joint Sealants for Flexible & Rigid Pavements Conference May 20-21 1997 Gerald F Voigt PE

(3) CALTRANS Department of Transportation Standard Specifications 2010

(4) IDAHO Transportation Department– Standard Speciation’s for Highways Constructions 2004

(5) Seal no Seal Group(www.sealnoseal.org) Concrete Pavement Joint and Crack Sealing (Originally Presented at World of Concrete, January 2012)

(6) Dow Corning Installation Guide accessed via web at www.dowcorning.com

Appendix A

Sample Blank Questionnaire

1 Project Details1a Project Name:1b Head Contractor:1c Project Dates Award Final Opening1d Distance from Sea1e Project Length1f Annual Average Rainfall

2 Pavement Details2a PCP Length (C/Way km's)2b Paving Dates (MLP) Start Completion2c % Manufactured Sands (Base)2d Cement Source2e Flyash Source2f Admixture Source

3 Cutting and Sealing Details3a Cutting & Sealing Subcontractors Name3b Cutting Method Used3c Brand Silicon Sealant Used3d Sawcut Cleaning Methods Used

Compressed AirWire BrushHigh Pressure Water

4 Visible Defects4a Silicon Sealant Defects Visible4b Is Defect Silicon Sagging in Sawcut4c If Not Describe Defect4d Time after First Trafficking Defects Visible(Months)4e Are Defects Visible Along Entire Project Length4f Is Defect confined to Transverse Joints Only4g Does Defect Affect both Slow Lane and Fast Lane4h Is Defect more Pronounced in Slow Lane Wheel Path4i Do Any Samples Show Signs of Incomplete Curing4j Do Removed Samples exhibit full Elastic Behaviour

5 Possible Causes5a Have any Possible Causes been Identified?

Rev B 21/05/2012

To Be Completed for All Projects PAVED After 2005Concrete Pavement Project Summary

YES/NOYES/NOYES/NO

Appendix B

Summary Maps Pacific & Hume Highways Showing Projects since 2006

BALLINA

BYRON BAYBRUNSWICK HEADS

TINTENBARBANGALOW

MURWILLUMBAH

TWEED HEADS

MACLEAN

WOODBURN

NEWCASTLE

KARUAH

HEXHAMRAYMOND TERRACE

BULAHDELAH

FORSTER

TUNCURRY

TAREE

NABIAC

KEW

COOLONGOLOOK

KEMPSEY

PORT MACQUARIE

MACKSVILLENAMBUCCA HEADS

URUNGA

COFFS HARBOUR

WOOLGOOLGA

GRAFTON

F3 F

WY

Upgrade completed todual carriageway

Upgrade approved and/orroute being prepared forconstruction

Under construction

LEGEND

Banora Point upgrade

Tintenbar to Ewingsdale

Ballina bypass

Coffs Harbour bypass

Sapphire to Woolgoolga

F3 Freeway to Raymond Terrace

Warrell Creek to Nambucca Heads

Frederickton to Eungai

Oxley Highway to Kundabung

Failford Road to Tritton Road (northbound carriageway)

Bulahdelah upgrade

Herons Creek to Stills Road

Open to traffic

Project approval obtained. Detailed design finalised

Under construction

Under construction

8 km section near Macksville under reviewwith rest of section being prepared for construction

Design construct contract awardedPreconstruction activities in progress

Project approval obtainedProcurement for main construction underway

Under construction

Concept design finalised

Project approval obtained and being prepared for construction

Concept design finalised

Under construction

Glenugie upgrade

Kempsey bypassUnder construction

Devils PulpitConstruction commenced

PACIFIC HIGHWAY STATUS OF DUAL CARRIAGEWAY MAY 2012

Open to traffic

Woolgoolga to BallinaConcept design preparedEnvironmental assessment

underway and beingprepared for construction

Kundabung to KempseyProject approval obtained and

being prepared for construction

Nambucca Heads to UrungaProject approval obtained

Procurement for main construction underway

Todd

Callout

C2HC Alliance (Thiess) MLP 11/2008 - 5/2010 Length 32km's 25% Joints Affected

Todd

Callout

Ballina Alliance (Leigtons) MLP 4/2010 - 1/2011 Length 12km 80% Joints Affected

Todd

Callout

Bonville Abigroup MLP 08/2007 - 08/2008 Length 10km's 50% Joints Affected

Todd

Callout

Karuah to Bulahdelah 2-3 (Abigroup) MLP 07/2008 - 09/2009 Length 23km's 25% Joints Affected

Todd

Callout

Brunswick Heads (Abigroup) MLP 2/2007 - 2/2007 Length 3km's Not Inspected

Todd

Text Box

Pacific Highway Summary of Concrete Paving Projects since 2006 All projects saw cut using Single Soft Cut Sawing All projects sealed with Dow Corning 888 Silicone

Barton Highway

COOLAC YASS

ALBURY

VictoriaWODONGA

Snow y Mts Hwy

GUNDAGAI

HOLBROOK

TABLE TOPMULLENGANDRA

WOOMARGAMA

To SydneyTo

Melb

ourne

TARCUTTA

LITTLE BILLABONG

KYEAMBA

KEAJURA

Sturt Hwy

PETTIT

BOOKHAMBOWNING

JUGIONG

YARRA YARRA

NSW

ACT

Oly m

pic H

wy

WAGGA WAGGA

0 10 20 30Kilometres

(c) Map Data Copyright 2001 Telstra Corporation United and Universal Press Pty Ltd

LEGENDWorks completed since 2007Works in planning, design or constructionExisting dual carriageway

Status : December 2011

N

Todd

Callout

Coolac Bypass (Abigroup) MLP 04/2008 - 06/2009 Length 14km's <1% Joints Affected

Todd

Callout

Tarcutta Hume Alliance (Leightons) MLP 11/2010 - 12/2011 Length 7km's Nil Defects Noted to date

Todd

Callout

Hume Woomargama Alliance (Abigroup) MLP 10/2009 -10/2011 Length 9km's 15% Joints Affected

Todd

Callout

Southern Hume Alliance (Abigroup) MLP 11/2008 - 07/2009 Length 41 km's 5% Joints Affected

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Northern Hume Alliance (Leightons) MLP 08/2007 - 11/2009 Length 35km's Nil reported but 10% visible

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Hume Highway Summary of Concrete Pavement Projects Since 2006 All projects saw cut using Single Soft Cut Sawing All projects sealed with Dow Corning 888 Silicone

Appendix C

Spread sheet Summary all Collected Data

1 Project Details NHA Bonville Coolac K2B HHSA C2HC BBA HHWA THA KBA

1a Project Name: Northern Hume Alliance Bonville Upgrade Coolac BypassKaruah to Bulahdelah

Sections 2&3Hume Highway Southern

AllianceCoopernook to Herons

Creek AllianceBallina Bypass Alliance

Hume Highway Woomargama Alliance

Tarcutta Hume Alliance Kempsey Bypass Alliance

1b Head Contractor: Leighton Contractors Abigroup Abigroup Abigroup Abigroup Thiess Leighton Contractors Abigroup Leighton Contractors Leighton Contractors1c Project Dates Start 01-Dec-06 01-May-06 01-May-07 01-Feb-07 01-Jan-06 01-Jul-07 01-Dec-07 01-Oct-09 01-Nov-10 01-Feb-09

Project Dates Finish 01-Dec-09 01-Sep-08 01-Aug-09 01-Dec-09 01-Sep-09 01-Oct-10 01-Jun-13 01-Oct-11 01-Dec-11 01-Dec-121d Distance from Sea (km) 250 5 210 10 275 6 5 260 350 151e Project Length (km) 35 10 14 23 32 32 12 9 7 141f Annual Average Rainfall (mm)/Yr 650 1700 427 1230 462 2382 1795 1032 450 1100

2 Pavement Details2a PCP Length (C/Way km's) 47 9 23 46 41 48 8.4 17 13 202b Paving Dates (MLP) Start 01-Aug-07 15-Aug-07 14-Apr-08 24-Jul-08 07-Nov-08 25-Nov-08 01-Apr-10 01-Oct-10 01-Feb-11 01-Feb-12

Paving Dates (MLP) Finish 01-Oct-09 20-Aug-08 17-Jun-09 10-Sep-09 16-Jul-09 20-May-10 01-Jan-11 01-Sep-11 01-Oct-11 01-Nov-12MLP Age (yrs) as of 1/08/2012 2.8 4.0 3.1 2.9 3.0 2.2 1.6 0.9 0.8 -

2c % Manufactured Sands (Base) Nil Nil Nil 20% of Mix Nil Nil Nil Nil Nil 16% of mix2d Cement Source BCSC - Berrima Blue Circle Berrima Blue Circle Berrima Cement Australia Boral Cement Berrima Cement Australia Cement Australia - Bulwer Island Boral Cement Berrima Boral Cement - Berrima Boral Cement - Berrima2e Flyash Source Mt Piper Eraring Mt Piper Eraring Mt Piper Eraring Tarong Mt Piper Mt Piper Eraring2f Admixture Source BASF BASF BASF BASF BASF BASF Grace BASF Grace Grace

3 Cutting and Sealing Details3a Cutting & Sealing Subcontractors Name Leightons-NHA Roadcut Australia Supercut Roadcut Australia Supercut Supercut Leightons - BBA Cut n Seal Leightons - THA Leightons -KBA3b Cutting Method Used Soft-cut with single cut P8 Soft-cut with single cut P8 Soft-cut with single cut P8 Soft-cut with single cut P8 Soft-cut with single cut P8 Soft-cut with single cut P8 Soft-cut with single cut P8 Soft-cut with single cut P8 Soft-cut with single cut P8 Soft-cut with single cut P83c Brand Silicon Sealant Used Dow Corning 888 Dow Corning 888 Dow Corning 888 Dow Corning 888 Dow Corning 888 Dow Corning 888 Dow Corning 888 Dow Corning 888 Dow Corning 888 Dow Corning 8883d Sawcut Cleaning Methods Used

Compressed Air Yes Yes Blower Yes Yes Yes Yes Yes Yes YesWire Brush No Yes Yes Yes Yes Yes No Yes Yes YesHigh Pressure Water No No No No No No No No No No

4 Visible Defects4a Silicon Sealant Defects Visible Yes Yes 1 Only Yes Yes. Yes Yes Yes. No None noted- too early4b Is Defect Silicon Sagging in Sawcut No Yes Yes. Yes Yes. Yes Yes Yes. No None noted- too early4c If Not Describe Defect - - - - - - - - - None noted- too early4d Time after First Trafficking Defects Visible(Months) N/A Unknown > 3 years Unknown Unknown 15 to 18 Months 10 -12 mnths Unknown No defects noted to date None noted- too early4e Are Defects Visible Along Entire Project Length No Yes No. Yes Yes. Yes Yes Yes No defects noted to date None noted- too early

Estimated % Faliures Visible 10% 50% 1% 25% 5% 25% 80% 15% 0 None noted- too early4f Is Defect confined to Transverse Joints Only N/A Yes Yes. Unknown Yes. No No Yes. No defects noted to date None noted- too early4g Does Defect Affect both Slow Lane and Fast Lane N/A Yes No. Mostly Slow. Mostly Slow. Yes Yes Mostly slow. No defects noted to date None noted- too early4h Is Defect more Pronounced in Slow Lane Wheel Path N/A Yes Yes. Yes. Yes. Yes Yes Yes. No defects noted to date None noted- too early4i Do Any Samples Show Signs of Incomplete Curing No ?? n/a ?? - Yes No - No defects noted to date None noted- too early4j Do Removed Samples exhibit full Elastic Behaviour Yes ?? n/a Did not remove any seal. - No Yes - No defects noted to date None noted- too early

5 Possible Causes

5a Have any Possible Causes been Identified?

Full inspection by RMS in Mar 12.

Only 3 minor silicon repairs required.

New seal post grinding is sagging.

Less than 1%, struggle to find another seal failure in

addition to the photo.

We estimate (by stopping at widenings) 20 to 30% of

slow lane seal failure. -

1-Cleanliness of the surface inside the cut.

On investgation and looking at lot records - the probable cause

is damp concrete.

By stopping at Widenings, approx 10 - 15% had seal

failure. - -Note at one intersection

joints have opened up and silicon has failed - this is

- - - - 2-Timing of seal after placement or rainfall(i.e wet

joint)

Ballina is a very wet region with regular stom activity - even

though joints appeared dry it is

-

- -

Note: The 10% of issues noted is Estimated based

on Observatiosn from Abigroup

- - - -3-Poor performance of

silicone due to mixing or batch issues.

Inspections of the silicon failed to find an deleterious material imbedded in the slicon which

indicates that the joint was clean and the silicon failed to bond to

the concrete joint face

-

- -

Past Concrete Pavement Project Summary

Appendix D

Letter from Dow Corning 21st May 2012.

Appendix E

Letter from Dow Corning 18th June 2012

silicone joint seal performance - ascp seal... · silicone joint seal performance . ... report to...

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