reducing water footprint of building sector€¦ · 3 a wwap 2018 the united nations world water...

September 12th, 2019

Reducing Water Footprint of building sector:

concrete with seawater and marine aggregates

Valeria Arosio1, Alessandro Arrigoni2, Giovanni Dotelli1

1 Dipartimento di Chimica, Materiali e Ingegneria Chimica, Politecnico di Milano,

Piazza Leonardo da Vinci 32, Milano, 20133, Italy

2 Department of Civil and Mineral Engineering, University of Toronto,

35 St. George Street, Toronto, Ontario M5S 1A4, Canada

SBE19 Graz

2

Presentation outline

Introduction

Goal of the study

Materials and methods

Results

Conclusions and further investigations

❑ Water stress and freshwater consumption in the building sector

❑ SEACON project

❑ Scope of the LCA

❑ Life Cycle Inventory

❑ Life Cycle Impact Assessment

3

a WWAP 2018 The united nations world water development report 2018: Nature-based solutions for water (Paris, France: UNESCO).b Miller et al. 2016, Readily implementable techniques can cut annual CO2 emissions from the production of concrete by ove 20%. ERL, 11(7)c Miller et al 2018, Impacts of booming concrete production on water resources worldwide Nature Sustainability 1 69-76

❑ ½ of the global population live in areas potentially scarce in water at least one month per year

❑ Concrete is the building material with higher rate of growth

Urbanization

Demand for

concretePopulation

growth

Pressure on

water resources

Annual global

water consumption

for concrete

Annual domestic

use of 145 million

US residents

16.6 billion m3

a

b

Industrial

annual water

consumption

Concrete

c

c

Introduction

4

Introduction

SEACON project

❑ Sustainable concrete using seawater, salt-contaminated aggregates

❑ Non-corrosive reinforcements: Glass Fiber Reinforced Polymer (GFRP), Stainless steel

5

Goal of the studyAssess the water footprint of concrete and investigate whether the use of seawater and

marine aggregates could reduce it

❑Marine Aggregates (MA)

❑ Sea-Water (SW)

❑ Land-won Aggregates (LA)

❑ Fresh-Water (FW)


❑ Sea-Water (SW)

LAFW

LASW

MASW

Goal of the study

6




❑ Sea-Water (SW)




❑ Sea-Water (SW)

LAFW

LASW

MASW

Goal of the study

7




❑ Sea-Water (SW)




❑ Sea-Water (SW)

LAFW

LASW

MASW

Goal of the study

8

ScopeDeclared unit

1 cubic metre of unreinforced fresh generic concrete delivered to the construction site

a Ecoinvent, dataset “Concrete, normal {CH}, unreinforced concrete production with cement CEM/IIA”

a

9

ScopeSystem boundaries

Aggregates production

Cement production

Mixing water extraction

Concrete

production

(batching

plant)

Cradle-to-gate analysis

10


LAFW


Cement production


Concrete

production

(batching plant)

Wet quarry Dry quarry Rock quarry

Well water

11


LASW

Cement productionConcrete

production

(batching plant)

Seawater

Wet quarry Dry quarry Rock quarry



12


MASW

Cement productionConcrete

production

(batching plant)

Marine aggregates

Seawater



13

ScopeGeography

Legend

Regional boundaries

Regions investigated

❑Lombardy

❑Abruzzo

❑Eastern Sicily

14

Life Cycle Inventory

Inventory of materials, energy and water flows

Geolocation of quarries, cement plants and batching plants

Geolocation of water intake and marine aggregates discharge facilities

Distance calculation

1

2

3

4

15

Life Cycle InventorySources of data

Cement plant

Rock quarry

Dry quarry

Wet quarry

Batching plantRock quarry

Dry quarry

Primary data

(API Google Distance matrix)

Primary data

(Producers)

Secondary data

(Ecoinvent, scientific literature)

16

Life Cycle InventoryGeolocation of quarries, cement plants and batching plants

Abruzzo Eastern Sicily Lombardy

Sources of data:

❑ Official regional websites

❑ Italian Association of Cement manufactures

❑ Italian Technical Economic Association for Ready-Mixed Concrete

Quarries

Cement plants

Batching plants

Legend

17

Life Cycle InventoryGeolocation of seawater intake facilities and marine aggregates processing plants

Point along coast at the minimal linear

distance from each batching plant

❑ Seawater intake facility

❑Marine aggregates processing plants

Intake facilities

Batching plants

Legend

18

Life Cycle InventoryFreshwater use

Water used in preceding processes, embedded in materials and energy flows entering

the process unit.

Indirect water use

Water used directly in the process analyzed.

Direct water use

19

Life Cycle InventoryDirect freshwater use

Dry quarry Wet quarry Rock quarry

❑Wash the machinary

❑Wash the aggregates



❑ Evaporation from quarry lake


❑ Dust control


20


Dry quarry Wet quarry Rock quarry





❑ Evaporation from quarry lake


❑ Dust control


Water consumption:

❑ Evaporated water

❑ Water incorporated in the final product

21


Cement plant

❑Wash the machinary and the yards

❑ Cooling activities

❑ Gas conditioning

Batching plant

❑Mixing the concrete

❑Wash the trucks

❑Wash the yards

Water consumption:

❑ Evaporated water

❑ Water incorporated in the final product

22

Life Cycle Impact AssessmentAWARE

AWARE characterization factors

❑ Unit of measure: 𝑚𝑤𝑎𝑡𝑒𝑟𝑤𝑜𝑟𝑙𝑑−𝑒𝑞3

𝑚𝑐𝑜𝑛𝑠𝑢𝑚𝑒𝑑𝑤𝑎𝑡𝑒𝑟3

❑ Account for the Available WAter

Remaining in a watershed after the

demand of humans and aquatic

ecosystems is met.

Direct water consumption

Indirect water consumption

Basin scale factors

National scale factors

Water Footprint = water consumption x characterization factor

23

ResultsOutline

Freshwater consumption in the base case scenario

Water footprint - base case scenario

❑ Abruzzo

❑ Eastern Sicily

❑ Lombardy

❑ Contribution of each unit process

Water footprint – Alternatives comparison

❑ LAFW → LASW

❑ LAFW → MASW

24

Concrete

batching plant

Cement plant

Rock quarry

Dry quarry

Wet quarry

LegendDirect water consumption


4.49

1.68

0.71

0.06

0.03

0.04

0.05

0.30

Range

0.76 - 4.56

0.01Range

0.75 - 4.55

ResultsFreshwater consumption (base case scenario)

0.50 0.05

0.01Range

1.67 – 5.47

Range

1.68- 5.48

0.36

0.01

0.35

1.7 - 5.5 𝑚𝑤𝑎𝑡𝑒𝑟3

𝑚𝑐𝑜𝑛𝑐𝑟𝑒𝑡𝑒3

25

Concrete

batching plant

Cement plant

Rock quarry

Dry quarry

Wet quarry

LegendDirect water consumption


4.49

1.68

0.71

0.06

0.03

0.04

0.05

0.30

Range

0.76 - 4.56

0.01Range

0.75 - 4.55

ResultsFreshwater consumption (base case scenario)

0.50 0.05

0.01Range

1.67 – 5.47

Range

1.68- 5.48

0.36

0.01

0.35

1.7 - 5.5 𝑚𝑤𝑎𝑡𝑒𝑟3

𝑚𝑐𝑜𝑛𝑐𝑟𝑒𝑡𝑒3

High value due to evaporation from quarry lake

26

ResultsWater Footprint base case scenario (LAFW)

0

50

100

150

200

1 2 3 4 5 6 7 8 9 10 11 12 13 14

wo

rld

-eq

uiv

ale

nts

m3

of

wate

r

Batching plants

WF of 1 m3 of concrete (D.U.) in Abruzzo

39

126

Concrete

transport

Cement

transport

Aggregates

transport

Mixing water

Batching plant

Cement plant

Aggregates

production0

20

40

60

80

100

120

140

160

180

200

1 2 3 4 5 6 7 8 9 10 11 12 13 14

39

126FC AWARE

27


0

50

100

150

200

1 2 3 4 5 6 7 8 9 10 11 12 13 14

wo

rld

-eq

uiv

ale

nts

m3

of

wate

r

Batching plants

WF of 1 m3 of concrete (D.U.) in Eastern Sicily

39

126

0

20

40

60

80

100

120

140

160

180

200

1 2 3 4 5 6 7 8 9 10

205

121

Concrete

transport

Cement

transport

Aggregates

transport

Mixing water

Batching plant

Cement plant

Aggregates

production

FC AWARE

28


0

50

100

150

200

1 2 3 4 5 6 7 8 9 10 11 12 13 14

wo

rld

-eq

uiv

ale

nts

m3

of

wate

r

Batching plants

WF of 1 m3 of concrete (D.U.) in Lombardy

39

126

0

20

40

60

80

100

120

140

160

180

200

1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81

1526

Concrete

transport

Cement

transport

Aggregates

transport

Mixing water

Batching plant

Cement plant

Aggregates

production

FC AWARE

61 %

46 m3eq

8 %

6 m3eq

17 %

13 m3eq

13 %

10 m3eq

29


Mean WF and share of each unit process in the regions investigated

46 %

10 m3eq

2 %

<1 m3eq

37 %

8 m3eq

12 %

3 m3eq

3 %

<1 m3eq

74 %

126 m3eq

9 %

15 m3eq

9 %

16 m3eq

7 %

12 m3eq

1 %

1 m3eq

1 %

<1 m3eq

0

20

40

60

80

100

120

140

160

180

200

220


wo

rld

-eq

uiv

ale

nts

m3

of

wate

r

30

ResultsAlternatives comparison

% -10% -7% -12% -8% -2% 0%

% -78% -50% -84% -75% -44% 20%


LAFW LASW

LAFW MASW

Mean, minimum and maximum WF in the different

alternatives in the regions investigated

WF variation from basecase scenario (LAFW) to

alternative mixes (LASW and MASW)

0

20

40

60

80

100

120

140

160

180

200

220


wo

rld

-eq

uiv

ale

nts

m3

of

wate

r

31


% -10% -7% -12% -8% -2% 0%

% -78% -50% -84% -75% -44% 20%


LAFW LASW

LAFW MASW





0

20

40

60

80

100

120

140

160

180

200

220


wo

rld

-eq

uiv

ale

nts

m3

of

wate

r

32


% -10% -7% -12% -8% -2% 0%

% -78% -50% -84% -75% -44% 20%


LAFW LASW

LAFW MASW





0

20

40

60

80

100

120

140

160

180

200

220


wo

rld

-eq

uiv

ale

nts

m3

of

wate

r

33


% -10% -7% -12% -8% -2% 0%

% -78% -50% -84% -75% -44% 20%


LAFW LASW

LAFW MASW





0.4

0.1

1.8

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Abruzzo Sicilia orientale Lombardia

wo

rld

-eq

uiv

ale

nts

m3

of w

ate

r

Water Footprint of the transport of 1 ton of

marine aggregates from the coast to the

batching plant

34

Conclusions

❑Aggregates production → determining parameter on the final overall freshwater consumption

❑Freshwater evaporating from quarry lakes → considerably increase the amount of water consumed in

case aggregates from wet quarries were used (i.e. up to 77% of the total consumption)

❑Mixing water → only a fraction of all the freshwater consumed along the production chain (i.e. from a minimum

of less than 2% to a maximum of 12%)

❑Seawater as mixing water → reduction of the WF of concrete up to 12% in Eastern Sicily, negligible effect on

the WF in Lombardy

❑Marine aggregates instead of land-won aggregates→ considerable reduction of the pressure of concrete on

freshwater availability in areas affected by water stress, leaving freshwater available for human consumption (i.e. in

up to 80% in Eastern Sicily); if aggregates need to be transported for a long distance and the area has a large

availability of freshwater, using marine aggregates might be detrimental for the WF

35

Conclusions







the WF in Lombardy





36

Conclusions







the WF in Lombardy




37

Conclusions







the WF in Lombardy





38

Conclusions







the WF in Lombardy

❑Marine aggregates instead of land-won aggregates

→ in areas affected by water stress → considerable reduction of WF (i.e. in up to 80% in Eastern Sicily);

→ if aggregates need to be transported for a long distance → possible increase of WF

39

Further investigations

Burden shiftings

Trasporto acqua di mare

Reinforcement elements

GFRP Stainless steel

❑ Durability

❑Whole life cycle

❑ LCC

Global warming potential Impacts on aquatic ecosystems

Carbon steel

40

Further investigations

Water evaporating from the quarry lake

Trasporto acqua di mareSensitivity analysis

❑ Different strenghts and water-to-binder ratios for concrete

❑ Desalinated water

❑ Municipal water network

Different provenience of freshwater for mixing

Area Temperature Productivity

THANK YOU FOR THE ATTENTION!

41

reducing water footprint of building sector€¦ · 3 a wwap 2018 the united nations world water...

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