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XIV DBCM CONFERENCE, Ghent,

Tuesday 30th May 2017

Federica Bertola

page 2 SEACON Project | Bertola| 30th May 2017

Buzzi Unicem

Buzzi Unicem is a multinational company focused on cement and concrete,

operating in 12 countries.

Headquartered in Italy, R&D laboratories in Italy and Germany.


Why we are involved in SEACON Project

• Industrial partner with know-how on cement, concrete and regular aspects.

• Strongly involved in a process of CO2 reduction involving the use of alternative

raw materials and production of cement with low clinker content.

• Steel reinforcement is not the ideal solution for low CO2 cement characterized by

lower pH and higher carbonation rate.

• Altering the perception of industry/public regarding the use of Cl- in concrete.

This will permit higher amount of Cl- in cement.


Background

• The construction industry uses several billion tons of fresh water annually to wash

aggregates and mix/cure concrete

• Environmental impact ad costs related to the extraction and use of natural fine and

coarse aggregates.

• The potential use of recycled raw materials (fuels, SCMs) in cement and concrete

production is limited by the chloride content

• The use of seawater and salt-contaminated aggregates is prohibited by standards and

codes due to associated risks of corrosion of steel reinforcement


Focus on topic

Up to now We want to use in concrete

Chloride Chloride


Scope

Safe utilization of seawater, high-chloride content

cement, and salt-contaminated aggregates (natural or

recycled) for sustainable concrete production when

combined with non-corrosive reinforcement.


Participants

Nine Partners & Collaborators


Politecnico di

Milano – LCA & LCC

(WP5)

Buzzi Unicem – Characterization of contaminated materials, effects of

seawater and salt-contaminated aggregates on concrete properties,

concrete mix-design (WP1)

University of Miami –

Characterization of GFRP bars and

study of the behavior of the

concrete+GFRP bars system (WP2)

Politecnico di Milano –

Corrosion study on different

type of reinforcing systems

(WP3)

All participants – Construction of field

demonstrators at two sites and on-site

monitoring (WP4)

Main tasks


Main objectives

• Make clear that chlorides are harmful for steel reinforcement, but they do

not damage the concrete’s characteristics (i.e., workability, strength

development, durability)

• Assess, through LCA and LCC, durability performance and economic

impact resulting from use of chloride contaminated aggregates, high-

chloride content cement and seawater on structural concrete

• Work at reinforcement level (improved SSR bar and use of GFRP bar in

concrete)

• Demonstrate technology by means of two real-size field prototypes in

Italy and Florida


Main target achieved

• Production of a dedicated cement (high-chloride content)

• Understanding of the effect that chloride from different sources can have

on cement and concrete

• Durability studies

• Construction of two demonstrators (Italy and US)


SEACON cement vs European Standard

UNI EN 197-1

Cement – Part 1: Composition,

specifications and conformity

criteria for common cements

CEMENTS Reference cement SEACON cement

XRD Rietveld analysis

0,30 4,25

1,14 2,04

0,18 1,11

Chemical composition (XRF spectrometry) 0,02 0,23


Chloride effect on cement pastes

Physical tests Reference

cement SEACON cement

Setting times (UNI EN 196-3)

Water (%) 28.6 28.4

Initial setting time (min) 210 140

Final setting time (min) 310 220

Laser granulometric analysis

Residue to 8 µ (%) 74.2 73.1

Residue to 24 µ (%) 38.1 38.9

Residue to 40 µ (%) 12.6 15.2

Specific gravity (UNI EN 196-6) (g/cm3) 2.98 2.98

Blaine fineness (UNI EN 196-6) (cm2/g) 3220 2805

Flow (UNI EN 1015-3) (%) 99 83

Cement Mixing water Presence of Cl- Effect of Cl-

Reference Freshwater - -

Reference Seawater In water Friedel’s salt (++)

SEACON Freshwater In cement Friedel’s salt (+)

SEACON Seawater In water and cement Friedel’s salt (+++)


Chloride effect on the compressive strength

Fresh water curing Seawater curing

Mortars


Chloride effect on durability – Shrinkage

Concretes Mortars

Higher surface tension of the pore solution when oversaturated with salts.


Chloride effect on microstructure

Mortars (water curing)

Mix Reference

Mix Seawater Mix SEACON


Chloride effect on durability –

Sulfate resistance and ASR reaction

Non-resistant sulfate cement: CEM II/A-LL 42,5R

Resistant sulfate cement: CEM I 52,5N-SR05

High-chloride content cement: SEACON cement

(CEM II/A-LL 42,5R + CKD)

Mortars


Italian DEMO


Italian DEMO


American DEMO (Halls River Bridge)


American DEMO (Halls River Bridge)


Conclusions

• The chloride effect on the hydration process of the cement was investigated by

XRD analysis. The formation of Friedel’s salt was proved (Cl- is chemically

bound).

• A densification of the microstructure due to the presence of Cl- was observed

by SEM/MIP investigation.

• The contamination of Cl- does not significantly affect the compressive strength

of both mortar and concrete, but an acceleration of the setting time was

observed.

• A strong effect of Cl- on the shrinkage behavior has been demonstrated. The

phenomena has to be completely clarified and a mechanism to counteract it

needs to be found (admixtures/CSA).


THANKS FOR YOUR KIND ATTENTION

Life cycle assessment of reinforced concrete unitsXIV DBMC CONFERENCE, GhentMonday, 29 May 2017Giovanni Dotelli

Giovanni Dotelli, dept. Chem., Mater. & Chem. Eng. «G.Natta»

SEACON PROJECT

ERA-NET Plus Infravation

SEACON - Sustainable concrete using seawater, salt contaminated aggregates, and noncorrosive reinforcement

Project partners and collaborators


Overview

Our role in SEACON projectTo assess through LCA and LCC environmental and economical performances resulting from use of chloride contaminated aggregates, high chloride content cement and seawater in structural concrete.

What we are going to presentFirst results on LCA of SEACON concrete mixes.


Goal of LCA

To reduce environmental burden of reinforced concrete by a careful selection of:

Cement type Cement plant Cement plant location Reinforcing bars


Functional Unit: reinforced concrete manufactured at lab scale (1 m3)

Mix design UM Amount

Cement kg/m3 400

Water L 200

Crushed limestone aggregates

kg 1704

Steel reinforcing bars kg 968


System boundary


Data sources

Primary data: transports means and distances

energy consumption

cement production

GFRP bars

Secondary data: steel reinforcing bars / aggregatesenergy mix, transports emissions


Methodology

Database: Ecoinvent 3.1 Software: SimaPro 8.2 Geographical boundary: Italy LCIA:

Recipe Midpoint (H) CML


Life cycle stages [CEM I 42.5R]

0

10

20

30

40

50

60

70

80

90

100

Perc

enta

ge (%

)

Materials Transports Manufacturing


Cement type effect

88

90

92

94

96

98

100

Perc

enta

ge (%

)

CEM I 42.5 R CEM II/A-LL 42.5 R CEM IV/A 42.5 R


Cement plant effect

EPD 2015

0.0

20.0

40.0

60.0

80.0

100.0Acidification

Eutrophication

Global warming(GWP100a)

Photochemical oxidation

Ozone layer depletion(ODP)

Abiotic depletion

Settimello* Siniscola Augusta Barletta

Guidonia Robilante Trino* Vernasca


Cement plant location

0

5

10

15

20

25

30

35

40

45

Perc

enta

ge c

ontr

ibut

ion

of tr

ansp

ort p

hase

to L

CA (%

)

Robilante Trino Vernasca Settimelo Guidonia Barletta Augusta Siniscola


Cement plant location

VERNASCA

TRINO

ROBILANTE

SETTIMELLO

GUIDONIA

SINISCOLA

BARLETTA

AUGUSTA

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400 1600

rela

tive

cont

ribut

ion

of tr

ansp

ort p

hase

distance to manufacturing lab [km]

Terrestrial ecotoxicity


High-chloride content concrete

SEACON cement (high-chloride content): CEM II/A-LL 42,5R + CKD (cement kiln dust) TRINO plant

Seawater from Genova RCA from Piemonte (burden free) Fly Ash from Piemonte (burden free) Concrete manufacturing in Milano


Concrete mixes

Units Referencefreshwater

SEACONfreshwater

Reference seawater

Referencefreshwater

RCA

SEACONFreshwater

FA

CementCEM II/A-LL 42.5 R kg/m3 335 335 335

SEACON kg/m3 320 325

WaterFresh water l/m3 175 175 180 180

Seawater l/m3 175

Aggregates

Sand/Gravel kg/m3 1093/744 1093/744 1093/743 985/369 1054/717

RCA kg/m3 347

Fly ash kg/m3 30 30 30 30 80

Additives Superplasticizer kg/m3 3.1 4.1 3.5 3.5 3.8


Concrete mixes

75%80%85%90%95%

100%Acidification (AP)

Eutrophication (EP)


Photochemical oxidation(POCP)


Abiotic depletion (ADP)

Reference freshwater SEACON freshwater Reference seawater

Reference freshwater RCA SEACON freshwater FA


Reinforcing bar

Carbon steel (CS) (Ecoinvent 3.1 database)

Stainless steel (SS) (Ecoinvent 3.1 database)

Glass Fibre Reinforced Polymer (GFRP) (primary data)


Reinforcing bar comparison:preliminary results (mass basis)

0%

25%

50%

75%

100%Acidification

Eutrophication


Photochemicaloxidation


Abiotic depletion

GFRP STAINLESS STEEL CARBON STEEL


Reinforced concrete:preliminary results

0.0

20.0

40.0

60.0

80.0

100.0Acidification

Eutrophication

GWP100

Photochemicalid i

ODP

Abiotic depletion

SEACON freshwater reinforced concrete

CS

SS

GFRP


Optimization parameters at design level

Cement Water Aggregates Additives Reinforcement

Type (SEACON, CEM II/A-LL 42.5R, …)

Type (freshwater,sea water)

Type (sand/gravel/RCA/fly ash)

Type(superplasticizer, …)

Type (CS, SS, GFRP)

Amount (kg) Amount (L) Amount (kg) Amount (kg) Amount (kg)

Production plant technology

- Production plant technology



Transport distance (km from cement production plant to construction site)

Transport distance (km from seaside to construction site)

Transport distance (km from aggregate production site to construction site)

Transport distance (km from production site to construction site)

Transport distance (km from production site to construction site)

Means of transport (EURO4, ….)






CONCLUSIONS

Factors positively affecting environmental performances of structural concrete:

Cement type Plant location Transport distances Recycled aggregates Reinforcing bars


Future work

Extend the LCA to the operational and End-of-Life phases LCA & LCC of the two demonstrators realized in Italy and USA

Perspectives:

Beneficial effects from the operational phase as a consequence of a prolonged service life and a reduction in maintenance operation

Reduced water footprint thanks to the use of seawater Definition of the End-of-life scenario for GFRP


THANKS FOR YOUR KIND ATTENTION

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