INNOVATION
MEETS SAMI
SAMI BITUMEN’S INNOVATIVE LOW-VISCOSITY CRUMB RUBBER BINDER IS HELPING THE VSA GROUP CARRY ON SEALING IN THE COLDER SEASON, WITHOUT USING KEROSENE CUTTERS. ROADS & INFRASTRUCTURE LOOKS AT THE BENEFITS GAINED ON A RECENT PROJECT IN SOUTH AUSTRALIA.
P
innaroo is the gateway to South Australia when travelling from Victoria and New South Wales on the Mallee Highway. The township was recently the site of a breakthrough highway resealing project conducted by Primal and InRoads – both part of the Victorian Sealing Alliance (VSA) – in collaboration with SAMI Bitumen Technologies. The work, which involved resealing on 115 kilometres of the Browns Well and Karoonda Highways for McMahon Services team, was unique in many ways. Firstly, resealing was carried out during April and May, a time of year when traditional resealing often poses quality and environmental risks due to cool climatic conditions. The project was also significant for its environmental and safety benefits, with no kerosene cutter used in the spray sealing process. These, and other efficiency and environmental gains on the project, were
made possible through what SAMI Bitumen Technologies’ Technical Services Manager Iulian Man refers to as a case of “double innovations.” Primal and InRoads were adopting their German-built synchronised bituminous surfacing technology, called the OBV production unit, on the project. The OBV technology, which the VSA team has been using on a variety of pavement projects in Australia over the past year, offers an innovative alternative to the traditional reverse aggregate spreading technique. In 2017, the State Road Authority of Victoria mandated against the ongoing use of reversing aggregate spreader trucks on spray sealing worksites due to several significant safety incidents. Whilst much of the surfacing industry subsequently focused on re-engineering the task of spreading aggregate in a forward direction by placing spreader boxes on the front of trucks, VSA
Roads adopted a holistic approach by using the OBV production unit to deliver a safer and more sustainable surfacing solution. The OBV technology offers significant safety advantages by eliminating the use of reversing tippers, minimising the number of plants on the jobsite – thus reducing the risk of collision – and operating at a reduced speed. The OBV also provides environmental benefits by eliminating the use of hazardous cutback bitumen, the need for stack sites on the edge of the road and significantly reducing aggregate wastage. Though adopting the OBV unit provided the VSA team with numerous safety and efficiency gains, the other aspect of the double innovation was the binder material used by the OBV crew. While traditionally kerosene cutters have been introduced at high temperatures to reduce the viscosity of crumb rubber binders in cool periods of the year, the VSA team
VSA Roads uses the OBV technology for spray sealing, which eliminates the use of reversing tippers.
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ROADS SEPTEMBER 2021
