INNOVATIVE INTEGRATED METHODOLOGY FOR THE USE
OF DECONTAMINATED RIVER SEDIMENTS IN ROAD CONSTRUCTION
Progress Meeting
September 10th 2015
Dott. Ing. Pietro Leandri
Dott. Ing. Patrizia Rocchio
Prof. Ing. Massimo Losa
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTIONS
B. Implementation actions
ACTION B.4: Demonstration of the use of decontaminated sediments in road construction
Specific technical goals :
- preliminary assessment of the optimum percentage of lime for the stabilization of sediments to be
used in the construction of the road section;
-construction of a road section for the demonstration of the use of sediment mixtures in the
construction of low volume roads.
C. Monitoring of the impact of the project actions
ACTION C.3: Monitoring and validation of the use of decontaminated sediments for road
construction
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION B.4
1stStep : Treatment of the dredged sediments
Main problem: excessive water content (that do not allow dredged sediments to ensure appropriate
bearing capacity). It is necessary to reduce the water content at least up to 15-20%.
In situ procedure: 30 cm lime layer was laid on a draining material and rehashed mechanically in
order to allow the air-drying.
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
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION B.4
1stStep : Treatment of the dredged sediments
Dewatering system for moisture control
TOP
MIDDLE
BOTTOM
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION B.4
1stStep : Treatment of the dredged sediments
Dewatering system for moisture control: Results
55.0
Water content (%)
50.0
Top
45.0
Middle
40.0
Bottom
Poli. (Mean value)
35.0
30.0
0
10
20
30
40
50
60
70
Time (days)
In controlled environmental conditions, the moisture content can be reduced up to 40%
after a period of 7-8 weeks
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION B.4
1stStep : Treatment of the dredged sediments
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 + H2O = Ca (OH) 2 + 15.5 kcal
The reaction is exothermic and heat generated from this chemical reaction further dries wet
sediments by driving it off as steam.
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION B.4
1stStep : Treatment of the dredged sediments
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.
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION B.4
1stStep : Treatment of the dredged sediments
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%.
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION B.4
Conclusion : Road construction
in order to reduce the water at a value near to Proctor moisture optimum level (19%), the lime
percentage required for the stabilization (5.2%) is increased up to 15%.
Double effect : stabilization of the sediments and drying
Dredged sediments dryed and
stabilized with lime
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION B.4
Completed with road construction
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION C.3
1stStep : Field investigation
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 D6951-03, UNI EN 13286-47:2012 );
 full characterization of the asphalt mix (volumetric and mechanical characteristics)
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION C.3
1stStep : Field investigation
Dynamic load plate test
Field density
Static load plate test
Dynamic Cone Penetrometer (DCP) test - CBR in
situ test
In situ tests on asphalt binder mixture by using a
Mobile Laboratory
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION C.3
Settlements monitoring
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
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION C.3
Settlements monitoring
Sounding manhole
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)
Murcia - September 10th, 2015
CLEANSED - LIFE 12 ENV/IT/000652
“Innovative integrated methodology for the use of decontaminated
river sediments in plant nursing and road construction”
ACTION C.3
Settlements monitoring 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)
Murcia - September 10th, 2015