A Reseal Contract Like No Other

A RESEAL CONTRACT LIKE NO OTHER: HOW EXTERNAL FACTORS UNITED IN UNPRECEDENT FASHION

Cameron Ives GenEng Solutions

Available in ANNUAL CONFERENCE PROCEEDINGS

Abstract:

Twelve months since the report into the seal failure where cars and trucks became ‘glued’ to the newly spray sealed road surface of Millaa Millaa-Malanda Road, an hour and a half south of Cairns, two of my reseals contracts in the TMR Darling Downs Region commenced during a severe drought phase. Additionally, they were impacted by bushfires including periods where two National Highways were closed at different times forcing traffic to utilise 2 OSCR roads (Gatton Clifton Road & Millmerran Inglewood Road) whilst reseal works were occurring. This was followed by a wet weather and flooding event delaying works pushing works from Level 1 into Level 2 of TMR’s new Tech Note 186 Sealing in Cold Weather implement as a recommendation after the Millaa Millaa-Malanda Road failure. At the end of the contract a Worldwide Pandemic COVID 19 lockdown and other procedures were implemented that made the completion of the contract a bit more interesting.

This paper goes through the mindset and actions taken by myself as TMR Administrators Representative and Sprayed Sealing Designer during these events.

Tech Note 186

August 2019 saw the introduction of the new TMR Technical Note 186 – Sealing in Cold Weather Conditions. For the Darling Downs District this meant Level 2 restrictions would be triggered for most areas in April and require would require additional mitigation measures to be documented and implement in a Spraying Sealing Management Plan.

2019-20 Reseal Contracts

CN-12630 Reseals in TRC area and CN-12631 Reseals in the WDRC areas were the two contracts that I was responsible for as the Administrators Representative. Both were worth approximately $2-3M each.

These were two of five contracts to be delivered during the 2019-2020 TMR Darling Downs Reseal Program and all contracts were the first in the regions to be delivered following the implementation of Tech Note 186.

The original program from the contractor had a practical completion date for both CN-12630 and CN-12631 as 31st March 2020. Therefore, the implementation of Tech Note 186 wasn’t considered an issue at the beginning of the contracts.

Drought Conditions / Bushfire Warnings

The region was in the midst of a drought and had current high bushfire warnings. Other local governments around the region had suspended their reseal program. TMR decided to continue with the program and implement to following conditions that were toolboxed by the contractor. • Heating bitumen, i.e. gas burners on bitumen tankers and the sprayer - the first shouldn’t be a problem as the heaters are pretty much sealed and no foreign object (i.e. dry grass) can get to the flame.

Also, they should be parked on cleared stockpile sites and never left unattended.

• Parking vehicles with hot exhausts in areas with long grass. • Bush fire preparedness and response - if there is a fire nearby, suggest we issue a stop work direction, remove any restrictions to 2-way traffic flow, make sure the site is safe and leave the area.

• Priority for Emergency Vehicles

Pechey Maclagan Road

CN-12630 was the first contract to commence and the first road to be resealed was Pechey Maclagan Road (AADT 290). A 20km 14mm S/S C170 seal both sides of Goombungee with a D/D 14/7mm seal through Goombungee. Pechey MacLagan Road runs west off the New England Highway just south of the township of Crows Nest. Shortly before the reseal

TMR (2019. p. 19)

commenced a bushfire broke out on the eastern side of the New England Highway in the Grapetree / Ravensbourne area. The Esk Hampton Road was cut off by the bushfire and closed to through traffic for a number of days. Emergency Rural Fire Brigade vehicles were given priority access through the reseal works during the time of construction.

On the 13th November 2019 the New England Highway, between Pechey Maclagan Road, Pechey and the Esk Hampton Road, Hampton was closed to allow back burning by fire units. During this closure both the Esk Hampton Road and New England Highway were closed meaning all traffic moving North / South along to this section of the New England Highway had to be diverted onto the newly resealed section.

On the 17th November 2019 the fire moved towards to the Township of Crows Nest with fear of an Ember Attack.

It was unknown how many additional AADT this added to over the period but the road appeared to hold up ok under the additional traffic load.

Gatton Clifton Road

Following the reseal of Pechey MacLagan Road, the contractor moved onto a section of Toowoomba Karara Road (AADT 472) and then a section of Greenmount Hirstvale Road (AADT 203) to complete S/S C170 seal. The contractor then established on Gatton Clifton Road to complete a 2 X 14mm S/S sections and 1 x 14/7mm D/D section all in M500. This section of Gatton Clifton Road has an AADT of 530. There was a 4km missing link section that was delayed from the contract due to additional time to complete the reseal prior works. This missing link section was going to be included as a variation at the end of the contract. The morning of the first seal we had a spare TMR Inspector available and they were requested to complete the reseal scoping the missing link section and complete the required sandpatch tests. About an hour after leaving the office I received a phone call from the inspector saying that he was able to do a run through and pick up the homogeneous sections, but wouldn’t be able to complete the sand patch tests because to the traffic volumes were too large. He also said he heard the Cunningham Highway may have been closed due to a bushfire and smoke hazards over the weekend and that might explain the extra traffic. I immediately phoned the TMR inspector inspecting the reseal contractor and asked how the traffic volumes were affecting the reseal works. The inspector said that traffic was a lot higher than he had expected and was concerned after the first spray run that the binder might be a bit heavy. He stated we were lucky we were using a multigrade binder instead of C170. I then discussed with the Darling Downs Traffic Control Centre about the last period of closure to the Cunningham Highway and was told it might only be for a couple of days. I then called the RoadTek Warwick office to confirm how long the closure would last and I was informed the closure could be for up to 2 weeks to complete some repairs following the fire. I immediately phoned the TMR inspector to discuss the impact on the design for increased traffic for a 2 week period.

We had discussions with the Contractors Project Manager to see if we could eliminate the risk by moving to another road until the temporary increase in traffic was over. We nominated the Oakey Cooyar Road which had the same M500 binder as Gatton Clifton Road but the contractor said that stone hadn’t been delivered to site and all available truck drivers were assisting with the firefighting operations at the Crows Nest Fire. The contractor then offered to be stood down by the Principal for 2 weeks period. I then phoned the TMR Inspector and Administrator to discuss the risks and the decision was made to review the seal design and continue to proceed with the reseal. The ready availability of a spray truck, stone and the M500 binder gave us confidence that we could rapidly address any issues that arise.

A quick analysis of the AADT for Cunningham Highway and anecdotal information from those on-site lead to review the design with a doubling of traffic. The seal design was reviewed by doubling the traffic which reduced the binder spray rate by 0.1L/m2. This reduction meant that the binder application rate stayed above the stripping limit for when the traffic reverted back to normal. I also notified the contractor that based on anecdotal information that the traffic is above 1000 AADT and therefore portable traffic lights should be implemented and to review the end of queue lengths signage is appropriate. I was told they will review and monitor and didn’t implement the portable traffic lights.

The Gatton Clifton Road connects the New England Highway to Gatton between Toowoomba and Warwick. With the Cunningham Highway closed all vehicle that would usually travel along that road were being diverted through Toowoomba. With the modern-day GPS technology, the Gatton Clifton Road provides the fastest route and detours people off the New England Highway / Warrego Highway route and onto Gatton Clifton Road and straight over the fresh reseal. The GPS Technology along with Facebook posts on local groups and newspaper outlets encouraging people that the route was the preferred option is a scenario that wasn’t evident a few years ago.

The next step was to try to somehow reduce the through traffic from using the road. We placed VMS boards on at each end of the road notifying people that roadworks were occurring and to expect delays of up to 15 minutes. It was hoped most people would be encouraged to take the preferred route and detour through Toowoomba. Whilst travelling through the section to review the VMS were installed by the contractor traffic counters were spotted on a section near Mount Whitestone.

On the 18th November 2019 a traffic accident occurred on the Warrego Highway west of the Gatton Bypass closing all west bound lanes. Traffic backed up for about 5 km’s and all the way back to Grantham along the Gatton Helidon Road. This accident pushed further traffic onto the Gatton Clifton Road and even over the reseal on the Greenmount Hirstvale Road as traffic followed their GPS to get to Toowoomba.

About 6 month later the traffic counter information was made available which showed the weekly average AADT being closer to 2000-2500 nearly 4-5 times the normal AADT and well above the revised design on double the traffic.

Millmerran Leyburn Road

Following a reseals on Oakey Cooyar Road the Contractor moved to Millmerran Inglewood Road to complete a 14mm S/S S45R seal. The Contractor had completed 3 days of work before a safety incident occurred.

A pressure build up when the sprayer was filling from the tanker caused a suction strainer lid with a displaced O ring covered a Contractors personal with bitumen. The workers PPE gloves had bitumen leak down into the gloves and when he went to remove his PPE visor, he wiped bitumen across the side of his face. First Aid was immediately applied and later that day the contractor was flown via Lifeflight Helicopter from Millmerran Hospital to one of the Brisbane Hospitals for burns treatment.

Works were suspended until an investigation was completed.

Corrective actions from the investigation included:

1. The external suction strainer mechanism is to be removed from Contractors Spray Truck.

2. Implement corrective actions to prevent recurrence on all spray trucks fitted with the same style of external suction strainer.

3. Binder Transport company to reinforce the requirement for personnel involved in the transfer of bitumen to wear bitumen handling PPE including visor in the down position and heat resistant gloves at all times during the transfer of bitumen and when within 15m of a bitumen transfer operation.

Works commenced back onsite after 8 days and the contractor had 5 more days of spraying. On the 2nd day back, I was notified of a fire in the distance. I informed the TMR inspector to ensure everyone remained safe and if there were any concerns to evacuate the area. The fire was the beginning of the Cypress Gardens and Forest Ridge Fire west od Millmerran. The fire closed the Gore Highway to once again divert Highway traffic directly over the current reseal project. The S45R performed really well and there wasn’t any concerns from the inspector about the design spray rates.

Binder Shortages

During the month of January, the Contractor experienced binder shortage and was concerned about the ongoing availability and timeframes under the contract.

Precoated with Waste Oil

With only a same section of Fabric Seal on the Gatton Clifton Road that was delayed due to the availability of Geofab the contract then moved onto one of the other contracts. CN-12632 the variable reseal contract. This wasn’t one of the contracts that I was administering, but the contractor was procuring the stone from the same source as most of the upcoming CN12631 WDRC reseals. The quarry supplier had recently taken over the operations of the pit and wasn’t completely up to speed on the time periods for precoating. The TMR inspector queried the precoat and timeframe and following a visit to quarry, realised that the quarry had been precoating the stone with solvent precoat that contained waste oil and making it available for use after 7 days.

The Contractor then completed some stripping tests to demonstrate the stone should be suitable for use on the variable contract, but were told the minimum time periods were required to be met for the CN12631 contract.

February Floods

Following completion of the Variable Contract the focus turned to my CN-12631 reseal program and the drought broke. A low dumped over 260mm of rain across the Western Downs area cutting off roads and causing disrupting the program. During the wet weather events

TMR (2020. p. 6)

we need to be careful to get as much repairs completed as possible. WDRC staff were busy completing emergent works on their own network at the time. We also needed to ensure that the stone supplied and used was clean and especially dry as they weren’t covered in the quarry and can get wet in the stockpiles. The 9 days extension of time started to push us closer to the 1 April and into Tech Note 186 Level 2.

COVID-19

It was about this time that no longer mysterious virus call COVID-19 was affecting city in Wuhan, China. Being some of Scott Morrison’s essential workers we remained at work but had concerns around the availability of materials and men if supply chains broke down or someone in the reseal crew, quarry workers or distribution worker got infected.

The Contractor was asked to prepare a COVID-19 management plan, which I’m sure wasn’t thought of as an issue at the commencement of the contract.

TMR also introduced some precaution measures to ensure we “flattened the curve”. For a period, Inspectors who had been in contact with external crews were excluded from the office and those who were office based weren’t allowed contact with the inspectors or field staff or to visit any other office in the district apart from their own.

The reduction in traffic (possibly up to 40%) then raised concerns about what a lack of traffic on the network would have on the reseals on Dalby Jandowae Road (AADT 1015), Surat Development Road (AADT 265), Condamine Meandarra Road (AADT 145) and Auburn Road (AADT 313 & 145).

Tech Note 186

After being reassured multiple time from the contractor that the works would run into the Tech Note 186 Level 2 period and several courtesy email to the Contractor expressing my concerns that a Sprayed Sealing Management Plan (SSMP) should be commenced and will need multiple reviews the contractor submitted a SSMP on the 26th March and gave TMR 3 working days to complete a review and get revisions. Works on Gatton Clifton Road and Auburn Road were completed under the Tech Note 186 with the additional mitigation measures.

References

• TMR, 2019, Technical Note 186 Sealing in Cold Weather

Conditions

• TMR, 2020, Transport and Main

Roads Specifications MRTS22

Supply of Cover Aggregate