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Report back on binder distributors. Trevor Distin. Introduction. Following the presentation made at RPF on issues relating to binder distributors it was decided to appoint a task team to: Investigate the need for and relevance of calibration certificates
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Report back on binder distributors Trevor Distin
Introduction Following the presentation made at RPF on issues relating to binder distributors it was decided to appoint a task team to: • Investigate the need for and relevance of calibration certificates • Review the compliance criteria in terms of transverse distribution and develop a rational, practical method for on-site testing • Investigate spray tolerances for various binders • Develop a protocol for flushing and testing spray bars on-site in line with HSE requirements
Client Teuns Lewis Wally Bennett Dennis Rossmann Consultants Wouter Schreuder Russell Clayton Douglas Judd Contractors Gerry Reitsma Philip Kuun Charlie Backlund Applicators Densil Sadler Kevin Spence Kobus Louw RPF Binder Distributor Task team
Deliverables & Principles • Binders to be sprayed: • at the correct rate • within acceptable transverse distribution rate • within acceptable tolerance rates • and handled in a responsible manner wrt worker health, safety and environment
Deliverables & Principles… • TMH 2 to be revised as the new Industry standard and the completed document to be published as a Sabita or AsAc publication and possibly later as a TRH publication • The Industry should strive to become self regulating however the Industry needed to have controls in place
Task Team Activities 4 work groups formed to: • Investigate current practice for determining on-site measurement of transverse distribution of sprayers in RSA and overseas • Matrix for spray tolerances • Best practice guideline related to binder distributors and the environment • Safety guidelines around distributors
On-site measurement of transverse distribution of sprayers 5 different methods being used to interpret results of the “bakkie” test(3 nozzles per trough)
Method 1 • Highest value is 100% • All other values may not be less than 95% Method 2 • ± 5% deviation allowed from mean Method 3 • Difference between adjacent troughs may not be more than 5%
Method 4 • Results divided into three sets: Left wing, right wing and centre bar • Mean of each section may not differ by more than 5% from overall mean Method 5 (TRH 3) • One container under each extension • Two containers under main bar • Containers may not differ from each other more than 5%
On-Site Test - France • Absorbent carpet • 50 x 100 mm • or 100 x 50 mm • Carpet fits into a pan • Pans fit into a metal base • Place pans at least 50 m from start of spray • Determine mass before and after
On-Site Test - Austroads • Strip of ‘Innerbond’ at least 0,6 m wide placed transversely across the road • Light timber template 550 mm wide is placed over ‘Innerbond’ • Surrounding areas covered with paper • After spraying ‘Innerbond’ is cut into strips 50 mm wide and weighed to nearest 0,1 g
On-Site Test – New Zealand • Cover spray area with heavy building paper • Pads 200 x 50 mm with impervious backing • Pads mounted on 1000 x 300 mm steel plates or 1000 x 760 mm stiff cardboard
On Site Test – USAASTM D 2995 • Absorbent cotton pads - 203 x 102 mm adhered on heavy wrapping paper with adhesive • Pads and paper placed on long strip of metal backing sheet • Determine mass1 and mass2
The Way Forward • Conduct trials using absorbent material with hot polymer modified binders • Determine realistic acceptance levels for • “bakkie” test > 5% • fix pit calibration < 18% • Publish new criteria and method in TRH 3 • Establish a sprayer log book which records history of ‘bakkie’ tests
Matrix for spray rate tolerances Establish acceptable tolerances for binder spray rates according to: • Type of binder ie • conventional/emulsions • homogeneous • non Homogenous • Type of application • double/single seal • graded crush stone/sand seals • primes/dilutes • Traffic levels
Matrix for spray rate tolerances… • Base all acceptance criteria on % at spray temperature • Minimum lot size of 4, 000 litres • Proposed values to be revised and distributed for comments
Best practice related to binder distributors and the environment • Guideline document drafted on best house keeping practices covering: • Legal responsibilities Cradle-to-Grave • Transporting binders in sprayers • Temporary storage of binders on-site • Application of binders on-site • Final document to be incorporated in Sabita Manual 8
Safety around distributors • Incorporate changes from the latest revision of Austroads publication ‘Bitumen Sealing Safety Guide’ into Sabita manual 8
Summary • Concern over updating existing COLTO & TRH 2 documents • Need to expand membership to incorporate more clients to achieve buy in • Good healthy debate between all stake holders!