Questions from the Chamber 1. Water and vegetation getting under bitumen surfaces a primary source of road degradation. Therefore, why does BSC not seal the cracks in existing roads using hot bitumen to extend surface life? Photo below is sealing a crack in a bitumen road (stock photo). – • BSC has chosen to place its efforts in resealing complete sections as this is more cost effective and better value for money. Reseals ~$10/m2 including heavy patching and preparation Crack sealing ~$6/lm • Water getting under the pavement is due to the maintenance (or lack thereof) of the table drains and other drainage and vegetation management. Council has been increasing its vegetation management budget in the past three years and trying to address previous poor grading techniques which ignored vegetation management and the need for roadside drainage.
Questions Continued 2. The hot- mix “ Snuffleupagus ” pours a hot mix of bitumen and gravel into pot holes. Is there a reason why the filled pothole is not compacted afterwards? – The crew need to be upskilled, compaction should be done • This statement is incorrect. The modern paveline type machines actually do not require manual compaction and the stone and emulsion is placed using compressed air. This is not to say that some works completed are not of a poor quality. We have put significant effort into retraining our crew and am awaiting a new truck which will improve our patching. • If you are referring to cold mix patching – then yes it needs to be compacted.
Questions Continued 3. A number of gravel roads have had potholes filled with bitumen hot-mix. Has this been effective and if so, why isn’t it done more frequently? • It can be effective but the intention is that this should only done as a temporary fix in higher risk areas when other plant is not available i.e. grader crew. These patches, although effective in the short term, cause issues when the grader crews get round to doing the maintenance grading. Also, if not removed they can cause weak points in the pavement. Therefore that is why there are only done on a limited basis, if too many are done it would be costly, plus slow down the maintenance grading team as they work through their programme • The preferred treatment is placement of gravel compacted, this still can only be temporary as it is difficult to get materials to bond to the failure surface.
Questions Continued 4. The ambient temperatures in Dorrigo do not get that high, relative to many parts of Australia. However, when Dorrigo does experience hot days, many bitumen roads start to melt resulting in either permanent degradation of the road surface, or the need for BSC to douse the roads with water for cooling. Is there a different type of bitumen used in Dorrigo to elsewhere, or is there some other drying/setting process needed to ensure a strong surface which does not suit the Dorrigo climate? • This issue occurs nationwide, New standards do not deal with temperature well (the problem is 10x worse in hot climates). • Cold Emulsion seals can be considered but they also have their issues. • Most seals perform well. The new design standards specify less stone and more bitumen.
Questions Continued 5. What is the procedure for reporting a pothole to BSC? Is there a more efficient method then telephoning or emailing the general BSC contacts details, as these reports seem to more often than not get lost, or misinterpreted? • Service request system, then requests are inspected and logged into our maintenance management system (REFLECT). If you do not receive a response please ring the Council – we need to know.
Questions Continued 6. A number of road repairs get repeated at the same location for the same degradation. What asset management techniques are is BSC using to identify that a repair has or has not been successful at a particular, specific location, so that future repairs can be improved upon. – Reflect • All issues are logged into our maintenance management system (REFLECT). • All defects are photographed before and after repair as Councils records.
Questions Continued
Questions Continued
Questions Continued 7. Please provide the (i) estimated construction period and the (ii) actual construction periods for the replacement and/or major repairs to the following bridges over the past 10 years: – Tyringham Road: Deep Creek, Little Murray River, Cut Bank Creek – Coramba Road: Bielsdown River near Billings Road – • Not interested in discussing the old urban myths and the past practices whether factual or not. We need to move on and focus on improved service delivery. • What I can say is that of recent years our bridge crews have been concentrating on minimising the disruption to the residents affected by works. If this means fully closing a road we may still need to do this following engagement with residents to ensure that transport options and emergency access can still be arranged. Tyringham Road: • Deep Creek – Construction period approx. 15 weeks. Change of scope immediately before works were to begin, changing a full precast design to cast in situ. Estimated at 12 weeks for cast in situ. • Little Murray River 2009 – I believe it was around the 20-22 weeks construction time on this one, with an estimated of much less than that. 2 flood events occurred during the middle of construction.
Questions Continued Little Murray River – flooding during construction
Questions Continued 7. Please provide the (i) estimated construction period and the (ii) actual construction periods for the replacement and/or major repairs to the following bridges over the past 10 years: – Tyringham Road: Deep Creek, Little Murray River, Cut Bank Creek – Coramba Road: Bielsdown River near Billings Road • Cut Bank Creek – Original scope of works was the replacement of 3 girders. Once on site scope increased to replace 9 as damage to the top face of the girders had been hidden by the deck. . Estimated timeframe 2 weeks, actual time on site 4.5 weeks. Lost time of 2 days for wet weather. Coramba Road: • Peaks – From what I can find estimated was 16 weeks, final construction was 17 ( I believe) History is History What about Whisky Creek – 7 day period – closed for 4 days only.
Questions Continued 8. The construction of the Reids Creek bridge on Kalang Road seems to have been a success. Is BSC (i) considering using this technology again in other areas – Yes. • Council considers replacement of all bridges on a case by case basis, with differing site conditions, traffic loadings, budget, priority and material availability influencing the end result. • This being said, we are seeking to simplify the number of different bridging systems used to replace/renew our bridge stock and systems such as Inquik and other precast options have shown great versatility. • A Request for Quotation is called for bridge renewals which allows the Council to test the current market and systems available at the time.
Questions Continued 8. The construction of the Reids Creek bridge on Kalang Road seems to have been a success. Is BSC (ii) considering completing closing some roads for a number of days to facilitate the rapid replacement of a bridge? • Again yes. Council possesses a number of large number of Timber bridges within its bridge stock, and to provide a full bytrack to traffic on every project is cost prohibitive. • Council has recently employed the use of a pedestrian only bytrack on a few of our bridge replacement jobs where a detour is available or short closure periods are expected. Examples of which include Feeneys Bridge on Coramba Road and Whisky Creek bridge.
Questions Continued 9. A number of roads on the Plateau have been recently re-sealed by applying a molten layer of bitumen and topping with gravel. a) Why isn’t the road levelled or made more smooth before over -topping with a new thin layer of bitumen? Doesn’t a bumpy road just result in more forces on the road’s surface (and vehicles) resulting in premature failure (of both)? • This theory is correct, however context must be considered, reducing the roughness will extend the life but in low traffic volume roads the degradation caused by the additional roughness is often minimal, we have to assess the net benefit and often the additional cost to fully re-work the surface does not provide that net benefit. Minor pavement corrections are made on identified sections. • Reseal - $10/m2, Rehabilitation $75/m2, Traffic volumes all under 200 VPD • We would only have achieved 9 km total reseals vs projected 66km during the past 3 years. This would not be considered best value for money • Average Roughness for Dorrigo is 137 counts, Rehabilitation trigger is between 250 and 300.
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