SUSTAINABLE MATERIAL TECHNOLOGIES IN HARBOUR CONSTRUCTIONS

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1 Image size: 7,94 cm x 25,4 cm Port of Tallin Conference, June 9th 2011 SUSTAINABLE MATERIAL TECHNOLOGIES IN HARBOUR CONSTRUCTIONS Utilisation of soft sediments in harbour fillings New eco-efficient harbour field constructions Dr. Pentti Lahtinen, pentti.lahtinen@ramboll.fi

2 Background Contaminated sediments have become a remarkable problem in harbours and waterways everywhere in the world. For example only in Europe roughly 200 million cubic metres of sediments are dredged each year (information: SedNet - European Sediment Research Network). In most cases they contain harmful substances originating from the operations of shipyards, industry etc. Economically and environmentally acceptable solutions to this problem have not been found so far. For example the maximum content of TBT (tributyltin) in the sediment is strictly regulated regarding the possible treatment alternatives. Contaminated dredged sediments are mostly classified as hazardous waste. The treatment is strictly regulated, expensive and problematic. 2

3 Development of mass stabilisation technology The mixing drum of ALLU Stabilization System The mass stabilization system of ALLU 3

4 Historical cases: Hamina, Finland 1996 The first mass stabilisation case Principle sketch of the applied construction for the new container terminal in the Port of Hamina 4

5 Hamina, Finland CONDITIONS IN THE BEGINNING OF WORK MASS STABILISATION IN PROGRESS READY MASS STABILISATION WITH EXCESS LOAD 5

6 Vuosaari Harbour, mass stabilization of TBTsediment, Test basin Sedimentlagoons 6

7 New harbour in Vuosaari, Helsinki

8 Stabilisation of contaminated dredged masses with fly ash binder admixture 8

9 Valencia in Spain Mass stabilization of a foundation for a container storage area of Port of Valencia in

10 LIFE06 ENV/FIN/ = STABLE Controlled Treatment of TBT-Contaminated Dredged Sediments for the Beneficial Use in Infrastructure Applications. Case: Aurajoki Turku, Finland is a project funded by LIFE Environment (acronym STABLE). One of the objectives has been to demonstrate a new environmentally friendly and cost effective method for the treatment of contaminated sediments. The pilot demonstration was carried out in Port of Turku, where dredged sediments from river Aura were stabilised and used for the filling of Pansio harbour lagoon. 10

11 STABLE-project shortly The demonstration project has been funded by EU LIFE-Environment and Port of Turku as well as the consortium for the project: Terramare Oy, Biomaa Oy, Fortum Power and Heat Oyj and the Regional Council of Southwest Finland Planning, binder mixture recipe and quality control have been made by Ramboll Finland Oy. The budget of the project was 4 million euros. STABLE-project started and it was finished

12 STABLE-project had five main tasks Binder mixture development. The contaminants in the dredged sediments, especially TBT, should be bound to a low-leaching state. The stabilised dredged material should also have technically appropriate quality for the harbour field structure. Testing and supervision of environmental grab technique Testing and supervision of the process stabilisation from dredging to stabilisation. The quality assurance of process stabilisation included e.g. sampling and testing of: the water from the stabilisation lagoon, stabilised dredged mass and bottom sediment outside the stabilisation lagoon. Life-cycle studies on the environmental impacts and costs of the stabilisation methods and their alternatives Dissemination to spread the information and knowledge in Europe. The project produced web-page, DVD presentation, power point presentation, conference presentations, articles, reports, press conferences and releases for media and other professionals etc. 12

13 Map of the contaminated areas in the river Aura. Highly contaminated sediments Contaminated sediments Contaminated sediments 13

14 Binder receptation It is very effective and economical to use industrial by-products. In the case of the river Aura the most effective by-products combined with cement are coal fly ash, blast-furnace slag and oil shale ash. 14

15 Binder receptation In Perno case, utilisation of coal fly ash as binder component was very effective and economical. 15

16 Binder receptation Results of a leaching test 16

17 Binder receptation 180d/150d d Problematic materials to stabilise - w %, w 2/04 w =237% Ignition loss 9,6% AJ10 (45Pika+105KJ+100LT) AJ10 (60Pika+105KJ+100LT) AJ10 (70Pika+105KJ+100LT) AJ10 (45Pika+150KJ+100LT) AJ10 (60Pika+150KJ+100LT) AJ10 (70Pika+150KJ+100LT) AJ10 (70Pika+150KJ+100LT) AJ12,14,15,9,10 (60Pika+105KJ+100LT) AJ12,14,15,9,10 (75Pika+105KJ+100LT) AJ12,14,15,9,10 (45Pika+150KJ+100LT) AJ12,14,15,9,10 (60Pika+150KJ+100LT) AJ12,14,15,9,10 (75Pika+150KJ+100LT) 1-axial compression strength [kpa] w2/04 (45Pika+105KJ+100LT) w2/04 (70Pika+150KJ+100LT) Effect of long time period to the strength development 28d 90d

18 Effect of the variation of sediment material on strength 18

19 EU-Life STABLE LIFE06 ENV/FIN/ Controlled Treatment of TBT-Contaminated Dredged Sediments for the Beneficial Use in Infrastructure Applications. Case: Aurajoki (river Aura) Turku, Finland Dredging with environmental grab Transportation Process stabilisation Utilisation in harbour fillings 19

20 Transportation route of the sediments, Pansio lagoon 20

21 Environmental dredging Environmental grab 21

22 Mass stabilisation in the barge 22

23 The principle of process stabilisation Feeding of the the dredged sediment from barges to feeding tray Moistened binders belt feeding of fly ash FEEDING TRAY MIXING TRAY Dry binders silo I blast furnace slag silo II rapid cement UNLOADING OF THE STABILISED MATERIAL 23

24 The homogeneity of mass stabilisation compared to process stabilisation 24

25 INTEGRATED COORDINATION OF THE UTILISATION OF MATERIAL MASSES PROMOTES THE SUSTAINABLE DEVELOPMENT NOTHING WILL BE WASTED Requires: Material investigations in the beginning of the construction project. Also the utilisation of low-quality soil and contaminated soil shall be investigated. Integrated coordination and planning of the logistics for the material masses. Utilisation of high quality materials and selling them to another construction project if needed (case specifically) Planning of the beneficiation of the materials and stabilisation Utilisation of the materials and industrial by-products from the closely surrounding area 25

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27 EFFECT OF THE E-MODULUS OF A STABILISED BASE COURSE TO THE THICKNESS OF THE COVERING COURSE AND THE COSTS. 45, Price [ /m 2 ] 40,00 35,00 30,00 25,00 20,00 15,00 10,00 5,00 0,00 Price of conventional structure 39,16 /m 2 Price of stabilised structure 'Saving' Thickness of asphalt layer Thickness of asphalt layer [mm] -5, E-modulus (stabilisation) [MPa] 27

28 THE SITEMAP OF THE PILOT STRUCTURES, M 2 28

29 CONSTRUCTION OF THE PILOT STRUCTURE storage stacks stationary multimode mixer 29

30 CONSTRUCTION OF THE PILOT STRUCTURE asphalt spreading machine stabilising cutter 30

31 QUALITY CONTROL DURING CONSTRUCTION OF THE PILOT STRUCTURE The sam ples from stabilisation site (analysed by Niton) Content of Ca x 1000 [ppm] 25,0 20,0 15,0 10,0 5,0 0,0 N1 /5.9. N2 /5.9. N3 /7.9. N4 /7.9. N5 /7.9. N6 /12.9. N7 /12.9. N8 /12.9. N9 /12.9. N10 /14.9. N11 /14.9. N12 /14.9. Target (at this case) Sample number and sampling day The content of calcium in samples taken and measured with Niton after stabilising cutter. The columns give an average value of five parallel measurements. 31

32 FOLLOW-UP STUDIES AFTER CONSTRUCTION OF THE PILOT STRUCTURE 32

33 Conclusions Industrial by-products like slag and fly ash make stabilisation of contaminated sediments economical. Blast furnace slag and fly ash are technically appropriate and they bind better chemical pollutants than commercial binders like cement. When compensating cement by fly ash and slag we can decrease the CO 2 emission dramatically in this case about tons. Totally new process stabilisation technology has been tested in full scale and the results were very good. It is possible to increase the capacity of the process stabilisation to even m3/h. The quality of process stabilisation is very good. Environmentally and technically appropriate quality can be obtained with a relatively small amount of binder material, which means remarkable saving in the costs of the treatment. 33

34 Conclusions Different transportation techniques have been tested and new technical opportunities were found to transport the stabilised sediment to the lagoon. The environmental grab in the dredging worked up to expectations. The water content in the dredged sediment was low, which meant that it could be stabilised with relatively small amount of binder. Consequently, significant cost savings were obtained. The strength development of the stabilised sediment has been observed in the field. The strength has increased like expected on the basis of the laboratory results. The filling area will be part of the new harbour area. About cubic metres of natural filling materials (gravel, blast rock) could be saved by using stabilised sediment. 34

35 THANK YOU 35