27/9/01 CFS0078 WERRIBEE 1966 TEST LINE - HISTORY & TEST RESULTS

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1 Memorandum 7/9/01 CFS0078 WERRIBEE 1966 TEST LINE - HISTORY & TEST RESULTS ABSTRACT Various pipe materials and protective systems for concrete were tested for performance in H S conditions in a 375 mm pipeline at the MMBW farm, Werribee, put into operation on October 6 th The 38 Resinag formulations examined were resistant to H S attack for a period of at least 8 years 7 months. The corrosion rate of the control (concrete) pipes was about.5 to 3 mm per year. A pipe made by the HPM process, and another concrete pipe which incorporated bactericide showed similar corrosion resistance to the controls. The ocrated pipe had improved resistance at early ages, as shown in earlier tests, and was still somewhat better than the control at the final inspection. Plastiline proved 100% effective over the test period. Thick coal tar epoxies also performed well in the pipe barrel but failures occurred at the joint and butt ends. The Techite GRP pipe was resistant to H S attack over the test period. Autoclaved asbestos cement pipe appeared to have superior resistance to non-autoclaved, but neither was resistant to H S attack and, on commercial thickness ratios, would lose strength at about the same rate as the concrete control pipes. Some of the pipes from this line including Resinag, GRP, coal tar epoxy linings and Plastiline were re-installed in the 1977 test line (NPD0101). HISTORY Following the successful installation in 1963 of a test chamber for evaluation of pipeline materials in H S, at the MMBW Werribee Sewage Farm, a 375 mm diameter test pipeline was laid at another location on the Farm and put into operation on October 6 th Sewage was diverted from a carrier channel through a valve and weir to give a constant flow level through the line, and with a sealed gas atmosphere above the flow level, highly corrosive H S attack conditions were created. The pipeline initially consisted of 48 no. pipes 375 mm diameter and 600 mm long, manufactured at the Westall Laboratories. The prime objective of the test program was an evaluation of Resinag, and 3 of the test pipes installed in the line initially were of this type having a range of material formulations and variations of the manufacturing process. The early indications from the Test Chamber were that thick coal tar epoxy coatings, plasticised PVC linings, bactericide addition and ocrating were worthy of further investigation in a pipe mode and together with concrete controls (both spun and manufactured by the HPM process), this study resulted in 13 concrete pipes in the line. The remaining three specimens were asbestos cement pipes. 1

2 Full details of the initial installation are recorded in the R&D report CE.619 of 4 th January In April 1967 the test line was extended with the addition of one further coal tar epoxy lined pipe imported from the USA (Mainstay) and an ocrated asbestos cement pipe. In February 1968 one concrete control pipe and one Resinag pipe were removed and replaced with two GRP pipe lengths (Techite). In August 1970 two badly corroded control pipes were replaced with new control pipes. A coal tar epoxy lined concrete pipe and five Resinag pipes, all in good condition, were removed and replaced with six alternative formulation Resinag pipes. Regular inspections of pipe condition were carried out in situ, nominally annually, until the line was dismantled in May At this time all pipes were returned to the laboratory for a detailed examination which gave a much more accurate result than was possible in the difficult conditions of a site inspection. A list of all inspection reports is attached. Eleven pipes found to be in good condition were subsequently installed in the 1977 Werribee Test Line. EVALUATION OF RESINAG A total of 38 different Resinag samples were installed in the line, 6 of them for the full test period of 8 years 7 months, the others for shorter periods. Six were selected for further testing in the 1977 line. The basic Resinag mix contained basalt coarse aggregate and polyester (Monsanto Polylite 807) resin, and the line included 13 such pipes. The variations in these pipes were aggregate to resin ratio (ranging from 1:1 w/w through a standard 18:1 to :1) and internal coating 7 pipes were coated with epoxy, polyester bitumen or coal tar epoxies of various types. Four pipes with alternative brands of polyester resin were also included, making a total of 17 basalt polyester samples. A further 9 pipes utilised basalt coarse aggregate with different resins coal tar epoxies or epoxies at varied aggregate resin ratio. Alternative coarse aggregates were substituted for basalt quartz (3 samples), tuscanite ( samples), quartzite and granite 7 pipes all with polyester resin. The final series was based on furane resin 5 pipes with either quartz or granite aggregate. Performance Details One coal tar epoxy lined standard basalt polyester pipe was removed in good condition after 1 year 4 months, and five other lined similar pipes removed after 3 years 10 months showed some blistering of the lining material. The underlying Resinag pipes were not attacked.

3 When the test line was dismantled after 8 years 7 months and the 3 recovered pipes inspected there was no visible deterioration of the Resinag material itself although thin linings had blistered and peeled. Whilst six of the pipes had only been in service for 4 years 9 months there was no indication their performance would be any different to 6 pipes which had been there for the full term. Full details of the final examination are contained in R&D report RC.6966 of 19 th December All the Resinag formulations examined are resistant to H S attack for a period of at least 8 years 7 months. CONCRETE PIPES A total of 16 concrete pipes were included in the test line, for periods ranging from 16 months to the full 8 year 7 month life of the installation. Of these nine were control pipes (aggregate / cement ratio 4:1, basalt coarse aggregate, silica sand and Type GP cement), three were control pipes with special treatments (bactericide added, the HPM process and an ocrated sample), and four had protective coatings. Performance Details Inspections were carried out at ages of 1 months, 3 years 5 months, 4 years 9 months, 7 years 3 months on site and a final laboratory evaluation at 8 years 7 months. Results obtained are shown in Table 1 and the notes below. Table 1. Maximum Depth of Corrosion at Age Shown 1 year 9 months 3 years 5 months 4 years 9 months 7 years 3 months 8 years 7 months Control pipes number of samples Average corrosion depth 6 5 mm 6 10 mm 1.5 mm 14 mm 3 mm Control pipe with fluoride 3 mm 1 mm - 19 mm 5 mm (bactericide) addition HPM pipe 5 mm 10 mm - mm 5 mm Ocrated control pipe 1 mm 3 mm - 0 mm 1 mm Pipes with Protective Coatings 1. Plastiline Lining No corrosion evident at final inspection 8 years 7 months.. Coal Tar Epoxy Lining Mainstay coating chipped at ends (possibly during recovery), no corrosion. 3

4 3. Coal Tar Epoxy HP 47 Pipe removed at 3 years 5 months in good condition, pipe examined at 8 years 7 months had the barrel in good condition but corrosion had occurred at the joint vertical surfaces and spread. The corrosion rate of the control pipes was about.5 to 3 mm per year. There was little difference between the corrosion resistance of the controls and the HPM and the bactericide samples. The ocrated pipe showed improved resistance at early ages, as it had done in earlier tests, and was still somewhat better than the control at the final inspection. Plastiline proved 100% effective over the test period. Thick coal tar epoxies also performed well in the pipe barrel but failures occurred at the joint and butt ends. OTHER MATERIALS The test line contained two lengths of Techite GRP pipe and four asbestos cement pipes - two pipes from Singapore (not autoclaved) and two autoclaved pipes ex James Hardie. One Singapore pipe was ocrated prior to laying. Performance details After 7 years 4 months exposure the Techite pipes showed no visible attack. All the asbestos cement pipes showed surface softening and swelling at 1 year 9 months. This gradually increased and at 8 years the wall thickness destroyed was measured at 7 mm for the Singapore pipe which was not ocrated and ranged from 3 to 4 mm in the other pipes. Extensive delamination, up to150 mm from the pipe ends, had occurred in both the Hardies pipes, but not in the unautoclaved Singapore pipes. The Techite GRP pipe is resistant to H S attack for at least 7 1 /3 years. Autoclaved asbestos cement pipe appears to have superior resistance to non-autoclaved, but neither is resistant to H S attack and, on commercial thickness ratios, would lose strength at about the same rate as the concrete control pipes. CONTINUATION OF TESTS The following pipes from this test line were reinstalled in the 1977 test line: Techite Pipes Coal Tar Epoxy Linings pipes, Mainstay and HP 47 (patched) Plastiline 1 pipe 4

5 Resinag 6 pipes consisting of five quartz-silane-polyester or furane resin formulations and one granite-silane-furane mix. INSPECTION REPORTS CE th April 1967 RC.433 nd July 1968 RC th March 1969 RC th April 1970 RC th September 1970 RC.3931 nd November 1971 RC st July 197 RC th May 1974 RC th December 1977 KEYWORDS Asbestos cement pipes, Chemical attack, Coatings, Corrosion, Epoxy compounds, Field tests, Hydrogen sulfide, Resinag, Sewage, Performance tests, Plastiline. * * * * * This report was compiled by C.A.Baker Concrete Technology for CSR Humes. 5