INNOVATIVE INTEGRATED METHODOLOGY FOR THE USE OF DECONTAMINATED RIVER SEDIMENTS IN ROAD CONSTRUCTION Progress Meeting Pisa, February 25 th 2016 “CLEANSED LIFE 12 ENV/IT/000652”

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTIONS Pisa- February 25 th, 2016 B. Implementation actions ACTION B.1: Dredging, analysis and characterization of contaminated sediments Specific technical goals : -Laboratory characterization of sediments with the aim to identifying the most suitable position in the Navicelli canal where the material can be dredged in order to make the project more representative - Dredging, storage in a confined area of the dredged sediments, sampling in different locations of the storage area, handling and laboratory tests ACTION B.4: Demonstration of the use of decontaminated sediments in road construction Specific technical goals : - Preliminary assessment of the optimum percentages of treated sediments to be used in different parts of a road construction (foundations, intermediate layer, etc) - Design of the experimental road section - Road construction (2014) C. Monitoring of the impact of the project actions ACTION C.3: Monitoring and validation of the use of decontaminated sediments for road construction construction ACTION C.4: Life Cycle Assessment - LCA

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION B.1: Dredging, analysis and characterization of contaminated sediments 1 st step: Dredging sites individuation 2 nd step: Storage of sediments in a confined area Sampling and laboratory characterization Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ UNI CEN ISO/TS : Water content of a soil; CNR UNI 10006:2002: Classification of soil; UNI CEN ISO/TS : Soil texture limits; UNI EN :2010: Presence of organic components; ACTION B.1 ACTION B.1 1 st Step : Characterization of sediment samples from the “Navicelli Canal” for the selection of the dredging site Results: Sample ID1234 particle size distribution % pass 2.0 mm % pass 0.4 mm % pass mm Plasticity LL LP PI Group IndexGI17900 Soil classification CNR UNI A7-6 A2-6A2-4 Presence of organic components (UNI EN ) Yes No Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ UNI CEN ISO/TS : Water content of soil; CNR UNI 10006:2002: Classification of soil; UNI CEN ISO/TS : Soil texture limits; UNI EN :2010: Presence of organic components; % of organic components Results: ACTION B.1 ACTION B.1 2 nd Step : Characterization of stored contaminated sediments Sample ID12345 particle size distribution % pass 2.0 mm % pass 0.4 mm % pass mm Plasticity LL LP PI Group IndexGI Soil classification CNR UNI A7-6 A6A7-6A6 Presence of organic components (UNI EN ) Yes Organic components content [%] Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION B.1: CONCLUSIONS –Samples 1, 2 and 4 contain high percentages of organic components (usability threshold < 5%). These samples are classified in the A7-6 group, that represents the highly plastic clay. They cannot be used in road constructions because they are water sensitive materials. –Samples 3 and 5 are classified in the A6 group and contain high percentages of organic components. The typical material of this group is a plastic clay soil, 75% or more of which usually passes the 75 µm. Materials of this group usually have high volume change between wet and dry states and they can be used in embankment construction after treatment, but cannot be used in construction of subgrade layers. Because of the high organic content, a specific study is needed to assess to potential to be stabilized by using lime. ACTION B.4 Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION B.4: Preliminary assessment of the optimum percentages of use of the treated sediments Stabilization of sediments with lime Stabilization of sediments with lime Determination of the Proctor compaction curve: Determination of the Proctor compaction curve: relationship between the water content and the dry density of mixtures after compaction in standard test conditions It allows to estimating the mixture density that can be achieved in situ. Determination of the CBR Index: Determination of the CBR Index: to characterize the bearing capacity of soil mixtures, determined immediately after compaction and after a period of curing in water Changing the behavior of the base material Stabilization for poor soils PURPOSES: Variation of the natural water content (w n ): CaO + H 2 O = Ca (OH) kcal Modifications of the geotechnical characteristics of the sediments in terms of water sensitivity EFFECTS: Pisa- February 25 th, EXECUTIVE DESIGN OF THE DEMONSTRATION ROAD SECTION 3.ROAD CONSTRUCTION 1.LAB STUDY: Preliminary assessment of the optimum percentages of treated sediments

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION B.4: LAB STUDY 1.Lime proportion requirement for soil stabilization 2.Plastic Index variation (with %CaO) Pisa- February 25 th, 2016 Stabilization of sediments with lime

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION B.4: LAB STUDY Proctor curves Optimum water content Pisa- February 25 th, 2016 Proctor curve

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Main problem: excess of water content (dredged sediments cannot be compacted to ensure appropriate bearing capacity). It is necessary to reduce the water content at least up to 15-20%. Laboratory procedure: realization of dewatering system for moisture control The sediment samples were tested periodically to check the variation of water content as a consequence of natural drying in order to assess the amount of water that the system naturally loses by evaporation and / or drainage. reproduced in a reduced scale: Environmental temperature and moisture conditions:  no rain and/or direct radiation  almost constant temperature (20°C) Field conditions :  lower drainage  lateral confinement  surface aeration In situ procedure: 30 cm layer was laid on a draining material and rehashed mechanically in order to allow the air-drying. Pisa- February 25 th, 2016 ACTION B.4 Treatment of the dredged sediments

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Dewatering system for moisture control TOP MIDDLE BOTTOM Pisa- February 25 th, 2016 ACTION B.4 Treatment of the dredged sediments

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Dewatering system for moisture control: Results In controlled environmental conditions, the moisture content can be reduced up to 40% after a period of 7-8 weeks Pisa- February 25 th, 2016 ACTION B.4 Treatment of the dredged sediments

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Dewatering system for moisture control: Results Remarkable difference between the in situ and laboratory processes:  in situ environmental conditions cannot be controlled  similarly to the laboratory process, after dewatering the sediments showed a water content of about 40 % after 5-6 weeks. the level is still too high to allow the sediments workability in order to reduce the water content and the dewatering process time, the partially dewatered sediments were mixed with lime Lime hydration process decreases the soil moisture content. CaO + H 2 O = Ca (OH) kcal The reaction is exothermic and heat generated from this chemical reaction further dries wet sediments by driving it off as steam. Pisa- February 25 th, 2016 ACTION B.4 Treatment of the dredged sediments

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ In order to reduce the water content up to the level required for compaction, dredged sediments were mixed in laboratory with different lime percentages and the related water loss was evaluated. Pisa- February 25 th, 2016 ACTION B.4 Treatment of the dredged sediments

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Lab stabilization results: %CaO versus water content The optimum water content of about 20%, determined by the Proctor compaction curve was obtained by using a lime percentage greater than 15%. Pisa- February 25 th, 2016 ACTION B.4 Treatment of the dredged sediments

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Navicelli Canal Dredged sediments stabilized with lime 1.Asphalt concrete (Binder course) th=10 cm 2.Granular Subbase th=20 cm 3.Natural soil th=50 cm 4.Subgrade layer made of soils classified in the groups A1-a, A1-b, A2-4 (CNR-UNI 10006/2002) th=30 cm 5.Fill material : dredged sediments stabilized with lime 6.Sand bedding th=30 cm 7.HDPE Geomembrane th=2 mm 8.Extensometer system for measuring settlements at various depths in embankment layers Pisa- February 25 th, 2016 ACTION B.4 Executive design of demonstration road

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ GENERAL PLAN Pisa- February 25 th, 2016 ACTION B.4 Executive design of demonstration road

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Pisa- February 25 th, 2016 ACTION B.4 Executive design of demonstration road

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION B.4 ACTION B.4 Conclusion : Road construction up to 15%. in order to reduce the water content up to a value close to the Proctor moisture optimum level (19%), the lime percentage required for the stabilization (5.2%) is increased up to 15%. Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Pisa- February 25 th, 2016 ACTION B.4 ACTION B.4 Conclusion : Road construction

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Pisa- February 25 th, 2016 ACTION B.4 ACTION B.4 Completed with road construction

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Each layer was laid only after the situ performance check of the layer to be covered. The following parameters were monitored in situ:  moisture content of dredged sediments stabilized with lime (BS 6576);  field density of dredged sediments stabilized with lime was measured after compaction by the sand-cone apparatus (CNR BU n. 22/72);  elastic Modulus of compacted layers by using the static and dynamic plate load tests (B.U. C.N.R. n. 146/1992, ASTM E2835–11; ASTM E2583–07 (2011) ); this parameter is a good indicator of the bearing capacity of the embankment;  In-situ and laboratory CBR index (ASTM D , UNI EN :2012 );  full characterization of the asphalt mix (volumetric and mechanical characteristics) Pisa- February 25 th, 2016 ACTION C.3 ACTION C.3 1 st Step : Field investigation during construction

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION C.3 ACTION C.3 1 st Step : Field investigation during construction Field density Static load plate test Dynamic load plate test Dynamic Cone Penetrometer (DCP) test - CBR in situ test In situ tests on asphalt binder mixture by using a Mobile Laboratory Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Before After Rutting: a permanent deformation on the pavement surface produced by vehicle loads Evaluation of rutting resistance of asphalt pavement ACTION C.3 ACTION C.3 1 st Step : Lab investigation Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ Fatigue resistance evaluation ACTION C.3 ACTION C.3 1 st Step : Lab investigation Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ The monitoring activities will be completed through the measurement of settlements over time in order to evaluate the behavior of the embankment under working conditions (traffic loads) Pisa- February 25 th, 2016 ACTION C.3 ACTION C.3 2 nd Step : Field investigation under working conditions

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION C.3 ACTION C.3 2 nd Step : Field investigation under working conditions Ruth depht evaluation Ruth depht evaluation by the use of a laser profilometer Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION C.3 ACTION C.3 2 nd Step : Field investigation under working conditions In order to evaluate the behavior of the embankment under working conditions, a magnetic extensometer system for monitoring settlements over time was installed Installation of extensometer system during construction Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION C.3 ACTION C.3 Settlements monitoring Sounding manhole The monitoring activities are being completed with the measurement of settlements over time in order to evaluate the behavior of the embankment under working conditions (traffic loads) Pisa- February 25 th, 2016

“Innovative integrated methodology for the use of decontaminated river sediments in plant nursing and road construction” CLEANSED - LIFE 12 ENV/IT/ ACTION C.4 ACTION C.4 Life Cycle Assessment- LCA Pisa- February 25 th, 2016 Monitoring the impact of the project actions