paperChain project - Circular case 2 - Spain - Adriana Martinez (UPC) & Teresa Sancho (SAICA)

This project has received funding from the European Union’s Horizon 2020 research and innovation Programme under grant agreement N° 730305
CC2: WASTE PAPER ASH AS ALTERNATIVE HYDRAULIC ROAD
BINDER FOR SOIL STABILISATION.

This Project has received funding from the European union under the H2020 Programme under agreement number 730305
Waste paper ash:
An alternative hydraulic road binder for soil stabilisation
Outline
ü CC2 video
ü Introduction: White ashes as by product - Teresa Sancho, SAICA Q&E
Group Director
ü Solution provided: WPA may replace cement in soil stabilisation
ü Demonstration activities: design, implementation and monitoring
ü Lessons learnt
ü Conclusions

Saica Group Presentation
SAICA GROUP______________________________________________________________________
ð Spanish integrated packaging Group with HQ in Zaragoza and presence in 8
European countries and Turkey.
ð Composed by 4 divisions - Natur, Paper, Pack & Flex- and with 10,000 employees
(approx).
ð We are the third major paper producer in Europe, being our paper production
100% recycled paper.
SAICA’s STRATEGY ON WASTES______________________________________________________
ð The company's new Strategic Plan - Saica 2025 - establishes very demanding
objectives in this area, having set target rates for the recovery of the waste
produced in the 95% - 100% range, depending on the business unit.
ð This goal is fully aligned with the European Commission's Green Deal that boosts
circular economy, establishing the promotion of the use of Secondary Raw
Materials, and also with SDG No. 12, Responsible Consumption and Production.

Zero Waste: How to get this in Paper Division?
FIRST STEP: Waste –to –energy plant at the site of El Burgo de Ebro
ð In 2011 Saica Paper started-up a waste-to-energy plant in El Burgo de Ebro
(Zaragoza).
ð El Burgo de Ebro site concentrates three lines of recycled paper production with a
yearly output of 1,300,000 t paper/year approx. The site generates different
streams of wastes:
ð The plant is designed to produce 362,880 MWh/y of electrical energy,
ð The Waste-to-energy Plant manages to reduce the weight of the waste input by
85% (77,550 t/y).
Cellulose fibers
430,000 t/y
(max.) 515,000 t/y
Plastics Refuse
Biological Sludge from the ETP
RDF (Refuse-derived fuel) 85,000 t/y (max.)

FIRST STEP: Waste –to –energy plant at the site of El Burgo de Ebro
ð The process produces two types of ashes than sum-up a total quantity of 60,000 t/y:
§ 25% are the so-called "gray ashes" which are collected in the bottom of the furnace and
the slag retained before the off-gas treatment.
§ 75% are "white ashes" collected in the off-gas treatment area -sleeve filter-

SECOND STEP: White Ashes resource use______________________________________________
ð From 2012 Saica has been working on different alternatives to give a second life to
these wastes and in 2018 we accepted willingly the invitation of ACCIONA to
participate in the PaperChain project.
ð With PaperChain we have tested the use of the white ashes as a binder in road
construction in substitution of cement and:
1. We’ve cleared any doubt regarding their technical performance
2. We’ve confirmed their safety regarding environmental and health protection
ð The only pending point is the reclassification of this waste as a by-product:
1. All the information required has already been sent to the Spanish
Environmental authorities
2. REACH registration is also under way

SECOND STEP: White Ashes resource use . Concerns
But, although we’ve already initiated the procedure with the authorities, there is the
perception that the Spanish Government won’t accept our proposal, since the
Ecological Transition Ministry's criterion considers that no Waste management process
can deliver any product.
We’re trying to clarify the reasons why this could happen since from our point of view
there is no logic on this statement.
We also think that this consideration could affect the competiveness of the company
due to an unfair treatment, taking into account similar wastes that nowadays are
already legally commercialized as products in Europe.

WPA may replace cement in soil stabilisation
High cement demand is expected for local roads that may benefit from WPA
• Extensive rural roads can be stabilised to improve durability and save in
maintenance costs.
• The regional road network in Aragon is extensive and commonly remains in poor
condition. It requires permanent maintenance. Usually the method implies recycling
of the road section with cement addition.
• Relevant highways are projected in the vicinity of SAICA´s facilities, including the
A68 extension to the Mediterranean Sea.
Rural unpaved road Pavement recycling Highway soil-cement layer

WPA may replace cement in soil stabilisation
High cement demand is expected for local roads that may benefit from WPA
7%
19%
1%
13%
16%
10%
1%
33%
Cement consumption per type of civil work
Other civil works
Canals
Dams
Urban developments
Ports
Railways
Airports
Roads
Oficemen, 2016
4 Mtons in 2016, 1,3 Mtons for road projects in Spain,
many of them as hydraulic road binder
1 km highway 700 – 1000 tons
> 30 km of pavement recycling estimated
for 2021 in Aragon (> 3,5 Ktons of cement)

Stabilisation of 1 km of an
unpaved rural road (S-EST2
type)
Stabilisation of 1 km of a
service road (S-EST3 type)
560 m of a soil-cement
layer in a service highway
1
2
3
Pilots design, implementation and monitoring

Location and date of pilots construction
Ejea de los Caballeros
October 2018
Villamayor de Gállego
October 2018
La Font de la Figuera
October 2019
•1 WPA-stabilised layer S-EST2 type:
•2 WPA-stabilised layer S-EST3 type:
•3 WPA-stabilised layer soil cement-type:

Pilot 1 - WPA-stabilised layer S-EST2 type
Ripping Digging
• Location: Ejea de los Caballeros (Zaragoza)
• Field study: soil samples to characterize in laboratory and define the working formula

Characterization Unit
Soil type
S-EST2
California Bearing Ratio (CBR) - ≥ 12
Density (Modified Proctor) % max dry density ≥ 97
Collapse % < 0.5
Free swelling % < 1.5
Organic matter % of mass < 1
Soluble sulphate % of mass < 0.7
Minimum workability time Hour > 3

7
2%WPFA 3%WPFA
4%WPFA
2% WPFA 3% WPFA
4% WPFA
Pilot 1 – Working formula

7
Pilot 1 – Subgrade design
Final design:
- 25 cm WPFA soil-stabilised
- 10 cm graded aggregate
Working formula:
- 3% WPFA
- 10.8% water
- 97% Compaction degree

Dosing and mixing (3% WPFA) Compacting
Grading
Pilot 1 – Construction stage

WPFA-soil stabilised layer surface Load test (after 14 days)

TEST
Untreated soil
(Ref.) 3 % WPA - treated 3 % Ca(OH)2 - treated
Compaction test
(Modified Proctor) 2.05 t/m3 / 9.02 % 2.03 t/m3 / 10.8 % 2.019 t/m3 / 10.8 %
Swelling / Collapse 2.94 % / 0.48 % 0.12 % / 0.16 % 0.40 % / 0.51 %
TEST
UNTREATED SOIL
(Ref.)
REQUIREMENT SOIL + 3 % WPA SOIL + 3 % Ca(OH)2
CBR 7 DAYS SOAKED
95% MDD: 4.2
98% MDD: 5.6
100% MDD: 6.7
97% MDD ≥ 12
95% MDD:31
98% MDD: 47
100% MDD: 71
95% MDD: 29
98% MDD: 46
100% MDD: 68
Load plate test
(14 days)
N/A
Ev2 > 60 MPa E1
Ev2 > 120 MPa E2
Ev2 > 300 MPa E3
Ev2 >224 MPa (av.)
Subgrade E2
Ev2 >193 MPa
Subgrade E2
Pilot 1 – Quality control

Pilot 1 – Environmental monitoring
- A Preliminary Environmental Risk Analysis was conducted by TECNALIA in order to
assess any potential harm for the environment.
- Samples prior and after the construction works were taken. Leaching tests results
indicated to be far from potential impacts for groundwater quality standards.
- The potential risk was very low and there was no need for conducting an
Environmental Risk Assessment.

Pilot 1 – Technical monitoring
Methodology:
- Visual inspection of the pilot
- Comparison with the conventional stabilisation and the unpaved road.
Conclusion:
- The surface was perfectly preserved.
- No subgrade deformation was detected or transferred to the granular layer.
- Some specific points were affected by water runoff due to missing drainage
element in the roadside, which had no connection with the stabilization works.

Levelling
• Location: Villamayor de Gállego (Zaragoza)
• Field study: borrow soil to mix with WPFA and define the working formula
Milling

Pilot 2 – Spanish specifications for S-EST3
Parameter Standard Value
Mix
Compressive strength at 7 days (MPa) UNE-EN 13286-41 ≥ 1.5
Compaction degree MP test (%) UNE 103501 ≥ 98
Soil
Gradation, sieves 80, 2 and 0.063 mm (%) UNE-EN 933-2 100, > 20 and < 35
Organic matter (%) UNE 103204 < 1
Soluble sulphate (%) UNE 103201 < 0.7
Liquid limit UNE 103103 ≤ 40
Plastic index UNE 103104 ≤ 15
Ash
Hydraulic road binders - composition,
specifications and conformity criteria
UNE-EN 13282-2 Slaking
Compressive strength at 56 days UNE-EN 196-1 Strength class

Pilot 2 – Soil characterization
Sieve size (mm) Passing (%)
40 100
25 90.8
20 81.9
12.5 65.1
10 58.1
5 44.9
2 35.9
0.4 22.9
0.08 8.6
- Best quality soil according the PG-3
- ASTM: well-graded gravel with silt, GW-GM
- AASHTO: A-1-a
Parameter Value
Modified Proctor Max D (g/cm3) 2.160
Modified Proctor Opt M (%) 7.2
CBR Test, 95% MP density 46
Swelling (%) -

Pilot 2 – Laboratory stage
ü Modified Proctor test
ü Compressive strength
Specimen
Density
(g/cm3)
Optimum
moisture (%)
Soil 2.047 10
Soil+5%FA 1.980 10.5
Soil+7%FA 1.953 10.5

Pilot 2 – Laboratory stage
ü Short-term expansion
ü Long-term expansion

7
Pilot 2 – Pavement design
Final design:
- Subgrade crown 25 cm WPFA soil-stabilised
- Double bituminous surface treatment.
Working formula:
- 5% WPFA
- 8.2% water
- Delay time of 30 minutes
- Max Proctor dry density

The methodology was the same as in Pilot 1. A preliminary environmental risk analysis
was conducted. The main conclusions were similar to Pilot 1, but having the advantage
of a bituminous treatment on top reducing the potential risk of leaching and avoiding
direct contact.
An environmental monitoring plan was proposed and samples were taken from the
pilot, vegetation and underground and surface waters.
Test results indicated that the material can be
classified as Inert according to the Royal Decree
1481/2001, which regulates the disposal of waste by
landfill deposit.

Methodology:
- Visual inspections of the pilot road
Conclusions from the visual inspection:
- 6 months after construction the road condition was
good and no damages were observed (some loose
aggregate from the BST).
- 15 months after construction, some cracks (each 4
m) were observed in the cement stretch as a
consequence of the high stiffness developed by
cement. No cracking was observed in the WPFA
stretch and no swelling effects observed.

Methodology:
- Laboratory monitoring: samples taken from the construction site and were kept in a
climatic chamber for curing and tested at different ages.
Conclusions from the laboratory monitoring:
- Both mixes achieved a compressive strength higher than 1.5 MPa after 7 days.

Pilot 3 - WPA-stabilised layer SC type
• Location: La Font de la Figuera (Valencia)
• Field study: granular material for SC and the mix with WPFA

Pilot 3 – Spanish specifications for SC
CHARACTERISTIC UNIT STANDARD
MATERIAL TYPE
SC
WPFA-SOIL
TYPE SC
Binder content % by mass ofdry soil - ≥ 3 5 – 5.2
Compressive strength at 7 days MPa
UNE-EN
13286-41
≥ 2.5
≤ 4.5 Fulfilled
Density (Modified Proctor test) % max. density UNE 103501 ≥ 98 Fulfilled
Particle size distribution (of the
original soil/aggregate) - UNE-EN 933-1
Grading envelope
SC40 Fulfilled
Soluble sulphatecontent (of the
original soil)
% by mass ofdry soil UNE 103201 > 0.5% null
Organic matter content (of the
original soil) % by mass ofdry soil UNE 103204 ≤ 1 0.17
Plasticity index oftreated
material -
UNE 103103
+ UNE 103104
LL < 30
PI < 12 Non-plastic

Pilot 3 – Spanish specifications for SC
Layer thickness cm -
≥ 20
≤ 30 20
Workability period hours
UNE-EN
13286-45
Full width procedure:
Wpc ≥ 3
Lane by lane
procedure: Wpc ≥ 4
≥ 4
Stabilised-soil moisture at
compaction
% by mass ofdry
components
UNE 103300
-1% / +0.5% of
Modified Proctor test
opt. moisture
±1,5% but fulfilling
target density in
all cases
Transverse pre- cracking
distance
m -
≥ 3m
≤ 4m 3.5 m
Curing and surfaceprotection
of the stabilised layer -
PG-3,
art.: 532
Bitumen emulsion curing
coat within 3 hours of
finalisation
Immediately after
final compaction
Traffic ban afterexecution
- -
To light traffic: 3 days
To heavy traffic: 7
days
More than 7
days

Pilot 3 – Granular material characterization
Tests carried out
1. Gradation (EN 933-1)
2. Atterberg limits (UNE 103103, UNE 103104)
3. Organic matter content (UNE 103204)
4. Sand equivalent EN 933-8)
5. Flakiness index (EN 933-3)
6. Los Angeles (EN 1097-2)
7. Modified Proctor (UNE 103501)
0,0625 0,125 0,25 0,5 1 2 4 8 16 32
Paasing
material
(%)
Sieve size (mm)
SC40 Max
SC40 Min
Soil

Pilot 3 – Working formula
Non-
treated
3% CEM
IV/B 32.5
4% WPFA 6% WPFA 8% WPFA
Max dry density and
opt moisture content
(UNE 103501)
2.241 t/m3
5.9%
2.242 t/m3
6.3%
2.172 t/m3
7.6%
2.156 t/m3
7.4%
2.103 t/m3
7.1%
5
4,5
4
3,5
3
2,5
2
1,5
1
0,5
0
3% CEM IV/B 32,5
4% WPFA
6% WPFA
8% WPFA
2% 3% 4% 5% 6% 7% 8% 9%
Binder content
UCS
at
7
days
(MPa)

Pilot 3 – Pavement design
Final design:
- Type SC 20 cm WPFA soil-stabilised
- 15 cm bituminous mixtures
Working formula:
- 5.2% WPFA
- 7.5% water
- Delay time of 30 minutes
- Max Proctor dry density

Soil-cement plant: conveyor belt and truck loading

Pre-cracking (left) and curing coat (right)

98% ref. dens.
2,04
2,06
2,08
2,10
2,12
2,14
2,16
2,18
2,20
0 2 4 6 8 10 12
Dry
density
(t/m
3
)
Moisture (%)
98% ref.
dens.
100% ref.
dens.
2,96
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
2,02 2,04 2,06 2,08 2,1 2,12 2,14 2,16
UCS
7
(MPa)
Specimen density s (t/m3)
p.k. 0+940
98% ref.
dens.
100% ref.
dens.
2,67
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
2,02 2,04 2,06 2,08 2,1 2,12 2,14 2,16
UCS
7
(MPa)
Specimen density (t/m3)
p.k. 0+830

The preliminary risk analysis indicated that this pilot was the less sensitive from the
environmental point of view because there was a bituminous emulsion and asphalt
layers covering it, avoiding the potential leaching.
There was no risk of dust emission like that of pilots 1 and 2. The ash arrives to the
construction site directly to the soil cement plant and is unloaded into the plant silo
by pumping in a closed circuit, so that, no dust is emitted in this process.

Technical monitoring consisted on an analysis of the UCS at different curing ages
to test the evolution over the long term.

Lessons learnt
Equipment:
WPA can be used with standard in situ soil stabilizer machines.
The wet system is not recommendable due to the high reactivity of WPA that may
trigger clogging in the injectors.
Density is a key factor for a proper dosing in both soil cement plants and stabilizers.
A short delay time is required before compaction.
Productivity:
Speed can be the same when replacing lime because of the similar density and
working formula.
Environmental concerns:
No affection was detected after a three-year monitoring. Wind speed must be
considered to avoid dust dispersion, as usual with any binder.

Conclusions
ü Roads contribute to economic development and growth. Keeping their
infrastructure under good condition is essential for a country or a region.
ü From the technical point of view, the results obtained indicate that the proposed
solutions are feasible.
ü From the environmental standpoint, they reduce the consumption of raw materials
and emissions to the atmosphere that are produced during the manufacture of a
conventional binder.
ü From the economic perspective, they foster a Circular Economy model by taking
advantage of a by-product from industry and boost the commitment of “Zero
Waste”.

This project has received funding from the European Union’s Horizon 2020 research and innovation Programme under grant agreement N° 730305
Thank you for your attention!

paperChain project - Circular case 2 - Spain - Adriana Martinez (UPC) & Teresa Sancho (SAICA)

Recommended

Recommended

More Related Content

Similar to paperChain project - Circular case 2 - Spain - Adriana Martinez (UPC) & Teresa Sancho (SAICA)

Similar to paperChain project - Circular case 2 - Spain - Adriana Martinez (UPC) & Teresa Sancho (SAICA) (20)

Recently uploaded

Recently uploaded (20)

paperChain project - Circular case 2 - Spain - Adriana Martinez (UPC) & Teresa Sancho (SAICA)