Are bitumen rubber & polymer modified binder sprayers different to normal bitumen sprayers are they calibrated & certified differently? – Sprayers are not calibrated differently for different products. Sprayers dedicated to applying Rubber Binders have the following unique features Augers in the bottom of the tank to keep the rubber in suspension. Double heating flues Duty Pumps Larger spray nozzles (35 40 l/min) – How are road surface types selected, is there a local or national norm, what factors are considered when selecting the given surface? Are there particular treatments used for particular reasons? The type of surfacing is selected based on similar factors as in Australia, traffic volume, road geometry, pavement condition. Other factors include the need to use labour based construction and the local maintenance capability. For example Cape seals may be specified where there is a low level of maintenance expected. Guidance on the use of particular treatment is provided in TRH3 Design and Construction of Surfacing Seals. Is the type of binder to be used included in the selection process or is that determined by the seal design process? The type of binder is a function of the traffic, road geometry and pavement condition and so forms part of the selection process. On national roads this process is undertaken by a consultant appointed by SANRAL who recommends a treatment and provides a basis for the selection. TG1 provides guidelines on the selection of the binder type which should be used. SANRAL only use modified binders on all their seals. Are polymer modified emulsions used in sprayed sealing? If yes what are the key motivators and what are the operational and cost implications? Modified emulsions are used extensively due to ability to be applied in a wider range of climatic conditions and as a SAM treatment. There is a cost penalty which ranges from 10 to 50% extra in comparison to a hot unmodified binder. Does the public sector participate in sprayed sealing (percentage private to public)? This varies between the Provinces, but some still undertake their own sealing on low volume roads. The majority of work is undertaken via contract. Are binders bought in bulk by the client? If yes how is binder allocated to contracts? Generally no however there are instances when a client will purchase directly from a refinery on an ad-hoc basis. Are newer sprayers with different international technologies being used?
Are bitumen rubber & polymer modified binder sprayers different to normal bitumen sprayers – are they calibrated & certified differently? Sprayers are not calibrated differently for different products. Sprayers dedicated to applying Rubber Binders have the following unique features Augers in the bottom of the tank to keep the rubber in suspension. Double heating flues Duty Pumps Larger spray nozzles (35 – 40 l/min) How are road surface types selected, is there a local or national norm, what factors are considered when selecting the given surface? Are there particular treatments used for particular reasons? The type of surfacing is selected based on similar factors as in Australia, traffic volume, road geometry, pavement condition. Other factors include the need to use labour based construction and the local maintenance capability. For example Cape seals may be specified where there is a low level of maintenance expected. Guidance on the use of particular treatment is provided in TRH3 Design and Construction of Surfacing Seals. Is the type of binder to be used included in the selection process or is that determined by the seal design process? The type of binder is a function of the traffic, road geometry and pavement condition and so forms part of the selection process. On national roads this process is undertaken by a consultant appointed by SANRAL who recommends a treatment and provides a basis for the selection. TG1 provides guidelines on the selection of the binder type which should be used. SANRAL only use modified binders on all their seals. Are polymer modified emulsions used in sprayed sealing? If yes what are the key motivators and what are the operational and cost implications? Modified emulsions are used extensively due to ability to be applied in a wider range of climatic conditions and as a SAM treatment. There is a cost penalty which ranges from 10 to 50% extra in comparison to a hot unmodified binder. Does the public sector participate in sprayed sealing (percentage private to public)? This varies between the Provinces, but some still undertake their own sealing on low volume roads. The majority of work is undertaken via contract. Are binders bought in bulk by the client? If yes how is binder allocated to contracts? Generally no however there are instances when a client will purchase directly from a refinery on an ad-hoc basis. Are newer sprayers with different international technologies being used?
2011_AAPA_Study_Tour_Report_v5-1_master.docx