L’INDUSTRIA DELLE OSTRUZIONI IN CALCESTRUZZO DI FRONTE …e9513cf3-4514-4046-9155... · 2019. 4....

Liberato FERRARAPolitecnico di MILANO

L’INDUSTRIA DELLE COSTRUZIONI IN CALCESTRUZZO DI FRONTE ALLE SFIDE DELLA

DURABILITÀ: IL CONTRIBUTO ITALIANO IN SINERGIA CON LA

VISIONE EUROPEA DEI PROGETTI HORIZON 2020 ReSHEALience ed ENDURCRETE

Liberato FERRARAPolitecnico di MILANO

“PENSARE” E “PROGETTARE” LA DURABILITÀ DEI MATERIALI CEMENTIZI: ANDARE OLTRE GLI

ATTUALI OBIETTIVI DI VITA DI SERVIZIO

CONSTRUCTION INDUSTRY

6% world GDP (8% in developing countries) – 100 mln direct jobs10 trln USD year revenues (+3.6 trln USD added value) (WEF 2017)

1% GDP investment in infrastructures generates a 1.5% GDP growth in 4 years

CURRENT SOCIETAL CHALLENGES

IN CIVIL ENGINEERING

Transportation Infrastructures :209 bn€/y investment 2021-2030

http://ec.europa.eu/growth/sectors/construction/index_en.htm

Coastal protectionEurope has a 66000 km coastline (3 times as much the one of US) (Italy 7600 km)

Coastal defense infrastructure market: 660 bn€/y + 4% year growth foreseen(climate change – 1.7mm sea rise each year)

http://ec.europa.eu/environment/iczm/state_coast.htm

Malta, March 5 2019 –Ricasoli Lighthouse



Green growth: promoting the growth of clean energy production

http://ec.europa.eu/environment/green-growth/images/priorities_for_circular_economy.jpghttp://www.oecd.org/greengrowth/greening-energy/greengrowthandenergy.htm





Blue growth: Sustainable growth in the marine and maritime sector as a whole, which so

far generates almost 5 bln €/year gross added value and represents 5.4 mln jobs (EU 28).

EC Blue Growth: Unlocking the potential of Europe’s oceans, seas and coasts.

CITIUS, ALTIUS, FORTIUS

CONCRETE FACING CURRENT SOCIETAL

CHALLENGES IN CIVIL ENGINEERING

10 bln ton/year ( 4 bln m3)More than twice the toal of all other building materials (e.g. steel 1.7 bln t/y)

The second largest used material after water

… and ARCHITECTURE

10 bln ton/year ( 4 bln m3)More than twice the toal of all other building materials (e.g. steel 1.7 bln t/y)

The second largest used material after water

CONCRETE: A PIONEER MATERIAL FACING

SOCIETAL CHALLENGES

PANTHEONRoma 113-125 d.C.

Il più antico edificio in calcestruzzo ancora esistente

43.44 mLa cupola in calcestruzzo non

armato di maggior luce

Il primo ESEMPIO di «FUNCTIONALLY GRADED

MATERIAL AND STRUCTURE»

«EXEGI MONUMENTUM AERE PERENNIUS» Horatius


CHALLENGES


CHALLENGES

WHAT SCENARIO?

55% world population lives in urban areas (up to 80% in high income countries)

every year about 1% of current world population (75 mln) relocates to urban areas

within 2045 67% of the world population will live in urban areas

- Increase of carbonation induced corrosion because of increased CO2 content in atmosphere and global warming

- Increased of chloride induced corrosion because of increased sea-water salinityand sea temperature as a consequence of global warming

- Increased physical «wearing» of concrete structures because of climatic stress due to increased frequency of extreme weather events


CHALLENGES

WHAT SCENARIO?

Carbonation corrosion: r/c structure built in 2000 Concrete C40 (w/c 0.5)

Climatic change vs stable conditionsTalukdar et al., ICE Proc, 2014


CHALLENGES

WHAT PERFORMANCE?

Damineli et al., Cement and Cconcrete Composites, 2010


CHALLENGESWHAT PERFORMANCE?


CHALLENGESWHAT PERFORMANCE?

CON-REP-NET project, showed that 50% of therepaired concrete structures failed once again, 25% ofwhich in the first 5 years, 75% within 10 years and95% within 25 years. This is just an example of theurgent need of a profound rethinking of the conceptand design processes for new and repaired R/Cstructures in aggressive environments in view of cost-effectiveness demands.

Matthews S. (2007) Journal of Building Appraisal 3(1): 6-20.

ReSHEALience consortium

COORDINATOR

www.uhdc.eu

WHAT PERFORMANCE for WHAT SCENARIO?

Durability is a key criterion for materials in many applications andenvironments. Longer performing materials can strongly reduceoverall lifetime costs, such as lower usage costs through reducedmaintenance and shorter service interruptions. Costs may also bereduced in the production phase (raw materials, energy, transport,formability), in the installation phase, and the materials may be moreappropriate for end of life reuse/recycling. Typical applicationsrequiring excellent long-term durability and high reliability arebuildings, marine applications and infrastructures including offshore.In many applications, operational durability needs to be betterunderstood, particularly for innovative products which have nodemonstrated long term performance

ReSHEALience project www.uhdc.eu

ReSHEALience project www.uhdc.eu• ReSHEALience (H2020 – GA 760824) – PoliMi coordinator (2018-2021)

• www.uhdc.eu

• Rethinking coastal defence and green Energy Service infrastructures throughehNhancEd durAbility high-performance fibre reinforced cement based

materials

http://www.uhdc.eu/

ReSHEALience project www.uhdc.euWHAT PERFORMANCE for WHAT SCENARIO?

Maximum w/c minimum cement content

minimum

compressive

strength

minimum

concrete

cover

maximum

crack

width

kg/m2 MPa mm mm

XS 0.40 - 0.65 300 - 400 25 - 40/50 25 – 75 0.1 - 0.4

150 (UHPC) 10 – 30 ?

XA 0.45 - 0.65

275

- 40025/30 to

40/50- 0.1 - 0.3325

325


Structures in XS exposures: pathologies

Hardbour dock Agadir (Morocco)Caisson dock Valencia

(Spain)


Structures in XA exposures: pathologies

Geothermal power plant cooling water tower (Italy)

The ReSHEALience approach www.uhdc.eu

A) DURABILITY

PROBLEMS IN XS / XA

B) IMPROVED CONCRETE

AND DESIGNS

C) INCREASE OF

SERVICE LIFE

UHPC + functionalities = UHDC

Nanofibers

crack initiation

and growth

Nanocellulose

densification of

matrix and ITZ

Self-healing

sealing

of cracks

Chemical Attack

Rebar corrosion

Biomass plant

Marine / Offshore


0 0.002 0.004 0.006 0.008 0.01

strain

0

4

8

12

16

(

N/m

m2)

beams L1/2

slab A

arctg Ec

DEWS L1/2-B

DEWS T1/2-B

UHP(FR)C technology

The ReSHEALience approach www.uhdc.euNanotechnology: there is plenty of room at the bottom


Diameter 4 – 11 nmLength 100-900 nm

Surface area 155 m2/g

Nanotechnology: there is plenty of room at the bottom

Al2 O3 nano fibres

The ReSHEALience approach www.uhdc.euNanotechnology: there is plenty of room at the bottom

Cellulose nanofibrils and nanocrystals

Diameter 5 – 200 nmLength > 500 nm

Cellulose crystallinity 88%

Diameter 4 – 5 nmLength 50 - 500 nm

Cellulose crystallinity 97%

The ReSHEALience approach www.uhdc.euSelf-healing technology: a concrete miracle!

Crystalline admixtures

1 month in water

(ISR 0.93 – ICH 0.9)

1 month air

(ISR 0.48 – ICH 0.4)

1 month 90% RH

(ISR 0.64 – ICH 0.64)

1 month 50% RH

(ISR 0.11 – ICH 0.2)

1 month wet/dry

(ISR 0.42 – ICH 0.52)

1 month in water

(ISR 0.93 – ICH 0.9)

1 month air

(ISR 0.48 – ICH 0.4)

1 month 90% RH

(ISR 0.64 – ICH 0.64)

1 month 50% RH

(ISR 0.11 – ICH 0.2)

1 month wet/dry

(ISR 0.42 – ICH 0.52)

Ultra High Durable Concrete (UHDC): “strain-hardening (fibre reinforced) cementitious material with functionalizing micro- and nano-scale constituents (alumina nanofibers, cellulose

nanofibers/crystals, crystalline admixtures, especially added to obtain a high durability in the cracked state under extremely aggressive exposure conditions”.





Structural design <=> material performance

Crack Strain

100%

0

1‰ X X X

2‰ X X X

0

0,2

Reference for KPI 100% improv.

Objective for KPI Expected Equivalent results

Autogenous Self healing - Base for self healing effect Main objective -- 30% improv. - Com

Objective for Self healing effect For SH verification

XXNo

30% Combined

with other

objectives

Test

Conditions

Concretes to be tesetd

KPIRef Concrete

C80/90Initial UHPFRC Developed UHDC

Initial UHPFRC

after Self Healing

UHDC

after Self Healing

X

X

Service conditions




TYPICAL COMPOSITION

Constituent Quantity [kg/m3]

Cement 52.5 R 600

Slag 500

Water 200

Superplasticizer 33

Sand 0-2 mm 982

Crystalline admixture 4,8

Nanoadditions 0.15-0.25% cem

Fibers 20/0.22 120

Cost?

Think beyond the €/m3 framework!!!We make structures not 1x1x1m cubes!



The ReSHEALience approach

A performance based durability education

www.uhdc.eu



www.uhdc.eu




A performance based durability education• Ultra High Durable Concrete (UHDC): “strain-hardening (fibre reinforced) cementitious

material with functionalizing micro- and nano-scale constituents (alumina nanofibers, cellulose nanofibers/crystals, crystalline admixtures, especially added to obtain a high

durability in the cracked state under extremely aggressive exposure conditions”.

• 6 pilots: Green Energy, Blue Growth, Architectural Heritage Conservation

Cooling towers water basins (IT)Geothermal drilling muds basins (IT)

Floaters for offshore wind towers (ES)Mussel farming rafts (ES) - Breakwater elements (IE)

r/c retrofitting (MT)

www.uhdc.eu

Liberato Ferrara

Department of Civil and Environmental Engineering

Politecnico di Milano

[email protected]

www.uhdc.eu

L’INDUSTRIA DELLE OSTRUZIONI IN CALCESTRUZZO DI FRONTE …e9513cf3-4514-4046-9155... · 2019. 4....

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