Port of Rotterdam. More than 50 kilometres!

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2 Port of Rotterdam More than 50 kilometres! 3

3 Development of the port

4 Salinity in the port 5

5 Port in figures Total port area 26,000 acres (net 12,500 acres) Total employment 350,000 people (140,000 regionally) Throughput 430 million tons, 11,1 million TEU (2010) Depth up to 75 ft (= 24 m) Port is growing westwards from the old town with fresh water of river Rhine into the salt Northsea Tidal zone ca. 2 meter in the whole port 6

6 Port infrastructure in Rotterdam Quay walls: total length 70 km Replacement value ~ 1.5 billion About 40 km with steel substructures, like combi walls, sheet piling, etc. 7

7 Asset Management on Quay Walls A quay wall s remaining lifetime and system integrity is mainly determined by the quality of the sub and superstructure. When the quay wall s integrity is in danger, it s often due to: concrete deterioration in the superstructure accelerated low water corrosion occurring at the substructure

8 Corrosion strategy (up to 1999) Corrosion rates according to EAU-Curves No steel but concrete in the splash-zone Extra thickness added to steel parts Inspection of a few quay walls every 5 year 9

9 What was discovered? Before cleaning with high pressure After cleaning with high pressure

10 Unexpected corrosion Original thickness including original coating Hole, followed by loss of soil Holes in tubular piles 11 11

11 Probable causes (long list) More salty environment Galvanic corrosion of combiwalls pitting influences on the strength Aeration due to extra oxygen by (bow) thrusters or cooling Fabrication process of steel parts Water flow Cathodic protection to the ship Vertical layering of water (temperature, oxygen, salinity) MIC Etc...

12 Action plan for investigation Stress corrosion test Coupon ladder Coupons (galvanic cells) Micro biological influence Weakening due to pitting Thickness measurement 13

13 Stress corrosion test 14

14 Coupons for galvanic corrosion test

15 Coupon ladder test

16 Results of coupon ladder Coupons corrosieladder Amazonehaven 0,0 0,000 0,050 0,100 0,150 0,200 0,250 0,300 0,350-2,0 Dieptes in meters t.o.v. N.A.P. -4,0-6,0-8,0-10,0-12,0-14,0-16,0-18,0 Corrosie in milimeters per jaar mm/jr 2003 mm/jr 2005 mm/jr 2008 Diepte (m) 17

17 Research influence MIC Sampling 18

18 Weakening due to pitting Kracht- rek diagram Westerkade kracht N coupon 1 coupon 2 coupon 3 coupon ,01 0,02 0,03 0,05 0,08 0,1 0,24 0,39 0,67 0,67 0,67 0,67 0,67 0,67 0,67 0,67 0,67 0,67 0,67 0,67 0,67 0, rek 19

19 Ultrasonic measurements Method: Ultrasonic measurement Inspection locations: horizontal & vertical Amount of inspections: one million points Inspection results processed statistically Representative values: (incl. pitting!) 20

20 Corrosion rate in specific conditions What is the salinity ( fresh, 10 ppm < brackish <25 ppm, salt)? Steel quality and electro-chemical corrosion? Biological activity (general in salt water, sometimes in fresh)? Galvanic cells (e.g. combi-walls, repair, welding joints)? Fabrication influence (e.g. purity mix, cold rolled)? Extra high oxygen level (e.g. propellers, cooling system)? High flow velocities because of geometry? Strong vertical differences in fresh and salt layers? Cathodic protection on board of moored ships? 21

21 Contribution of influences Causes / influences Fresh Brackish Salt 1 Electrochem. Corrosion 5% 5% 9% 2 Biological activities 5% 9% 18% 3 Galvanic influence 0% 9% 27% 4 Fabrication 0% 5% 5% 5 Aeration 5% 5% 9% 6 Local high waterflow 0% 5% 9% 7 Vertical salt-fresh layers 0% 5% 0% 8 Cath. prot. on board of ship 5% 5% 5% 9 Splash-zone 18% 18% 18% Relative Contribution 38% 66% 100% Avg. corrosion [mm/50yr] 3,4 5,9 9,0 Max. corrosion [mm/50yr] 10,3 17,8 27,0

22 corrosion [mm] avg max. Corrosion scales and measures 9 corrosion-scales Factor CP + m (+c) +d + m +cp (+c) +d + m Measures: d = extra thickness m = monitoring cp = start with cath. protection CP= Cathodic protection (c)= coating if needed 10 time [yr] 50 Subsets of uniform corrosion conditions and uniformized measurements

23 Overview Probable causes 1. Galvanic working 2. Biological activity Experts: 0-hypothesis ( 9 main causes ) Measurements on specific aspects: in lab in situ Tuning in practice: = uniform group 25

24 Then from scale to degradation Uniform group of measurements are placed on the corrosion scales (example: average 1,9 mm after 16 years) 26

25 Then from scale to degradation 10,000 Scale defenition corrosion scalel 9,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0, Inspection year schaal 1 schaal 2 schaal 3 schaal 4 schaal 5 schaal 6 schaal 7 schaal 8 schaal 9 wanddikte

26 Then from scale to degradation Uniform group of measurements are placed on the corrosion scales Extrapolation of corrosion within scales (example between scale 3 and 4) 28

27 Then from scale to degradation 10,000 standard scale 1 Standard Corrosion Scales Input new Quaywall 9, ,000 8 Total average corrosion [mm] 7,000 6,000 5,000 4,000 3, , , , Year

28 Then from scale to degradation Uniform group of measurements are placed on the corrosion scales Extrapolation of corrosion within scales Translation of corrosion to degradation (example remaining safety factor 1,30) Prediction of remaining lifetime 30

29 Then from scale to degradation 1,70 Degradatio nline 1,60 1,50 Safety factor 1,40 1,30 maintenance phase 1 maintenance phase 2 Degradationline beheerfase 1 1,20 Beheerfase 2 1,10 maintenance phase 3 Beheerfase 3 1, Year

30 Input for KMS KMS: Quay wall modelling system Port of Rotterdam s next step in asset management Supports the asset manager Combines technical risk and business value in order to prioritise maintenance measure Degradation model is part of KMS

31 Degradation model in KMS

32 Ongoing research to improve the steel model Coupontest on site USA Sohar and the Netherlans (for the reference) Water measurements: O 2 - ph - Redox EC - temp Lab test coupons Electrical chemical test for determination of accelerated corrosion rates Research in 2013 A + B + C + D Coupon frame Measurement waterconditions Coupontest Galvanostat/Potentostat-measurement H 1 hypothesis Divice: Hach Lange Z1AL L3 Locations Standard coupons Houston O2 Boston ph exhibition coupons in lab Corpus Christy Ec Sohar T under variation of: P.O.L.B Bart's (Microbiology ) ph Rotterdam (reference) T Upper layer O2 Mid. Layer S235JO S465 Sheetpiles Piles Bottom layer "Bart's test": Research on presence on sulfate reducer coupon weighting and measuring of water conditions, is always in combination potentiostat device Presentation corrosion research

33 Risks on CP systems Unsufficient protection Caused by anodes that don t work properly Incomplete coverage of structure Caused by mechanical damage Decrease of the anode lifetime Caused by higher load on anode than designed due to changing conditions 37

34 Monitoring of CP systems Visual inspections with divers mv measurement Weighing of anode to measure consumption in time US thickness measurement Condition monitoring 38

35 Monitoring water conditions Water conditions determine how efficient the system will work Monitoring of: Conductivity / Salanity Temperture of the water ph Dissolved oxygen 39

36 Results of mv is more than sufficient Brackish/ fresh water : anode consumption is lower than in salt conditions In salt water, the consumption is less at end of life of the anode Development of anode model 40

37 Thanks for your attention!