MYTHS, FACTS AND FALLACIES - APEB · F. Biasioli - Sustainability and costruction materials: myths,...

ERMCO

F. Biasioli - Sustainability and costruction materials: myths, facts and fallacies 1

1

SUSTAINABILITY

AND CONSTRUCTION MATERIALS:

MYTHS, FACTS AND FALLACIES

Francesco Biasioli

Secretary-General

ERMCO, the European Ready-Mixed Concrete Association

ERMCO


2

1. WHO IS DICTATING THE CONCRETE AGENDA?

CONTENTS

ERMCO


Looking from « outside », other

sectors seem to « dictate » our

agenda:

Sustainable development

CO2 footprint

Energy intensive product

Depletion of natural resources

PEFs - Product Environ. Footprints

EPDs – Environmental Product

Declarations

WHAT IS HAPPENING TO THE

CONCRETE SECTOR?

ERMCO


Some answers of the concrete sector:

Recarbonation after demolition

Life Cycle Asssessment (LCA) based

on a «cradle to grave» evaluation

Thermal mass

Circular economy

…….etc etc

Are these answers « weak » and/or

« too difficult » to be explained?

Are we « scraping the bottom of the

barrel »?

WHAT IS HAPPENING TO THE

CONCRETE SECTOR?

ERMCO


5

CONTENTS


2. WHY CONCRETE?

ERMCO


Why concrete?

Would it be better to simply recall the many good reasons

WHY (reinforced) concrete was and remains

the (after water) most used

construction material in the world?

To answer the question, we have to go BACK TO BASICS!

ERMCO


7

CONTENTS


2. WHY CONCRETE?

3. COMPARING MATERIALS: FAKE NEWS, MYTHS AND FACTS

ERMCO


Fake news

“…is the construction material with the highest strength “f” to specific

weight “w” ratio: this is why it is very efficient!”

…A well-designed timber structure has a section similar to one made

of (reinforced) concrete and weight similar to a steel one…”

WOW!

Wood is the

« perfect »

construction

material?

ERMCO


Loading a sample of a material to collapse gives its

collapse load F. Dividing F by the sample section

area A the (compression) collapse strength f is

f = F/A F = f A

If w is the “specific weight” (weight per unit volume)

of a prismatic element of height h, area A so volume

V = (h A), its total weight W is

W = w V = w (h A)

What is the maximum height hmax of a column of area A made with

such a material before it collapses under its own weight W?

W = F w (hmax A) = f A hmax = f / w

f/w : the strength to specific weight ratio

ERMCO


hmax = f / w

……the greater hmax, the better the material?

Steel (“s”) hmax,s = (4000x104) /7850 = 5100 m

Concrete (“c”) hmax,c = (400x104) /2500 = 1600 m

Timber (“t”) hmax,t = (400x104)/500 = 8000 m

According to the strength/specific weight ratio, timber

seems to be the “most efficient” construction material.

Very impressive! but ….what happens in the real world?

f/w : the strength to specific weight ratio

ERMCO


THE REAL WORLD LOOKS DIFFERENT

Source: wikipedia

Sequoia sempervirens

U.S. California Nat Park

h = 116 m

ERMCO


The engineer’s approach

1) Collapse strength f design strength fd = fk / m (d = “design)

2) Uniform section A section varying with height

3) “Buckling” does not allow to go that high “slenderness” limits

ERMCO


Comparisons one can trust

13

The “modified” hMAX, named the“slenderness radius”, takes

into account both design strength fd and slenderness.

Concrete and steel now are almost in the same range (11- 45),

ranking is in the correct “according to the nature” order - as in

the real world.

Both leave wood….. far away….

ERMCO


Comparing materials?

«Common sense» conclusion

when it comes to floating in water, wood is the best

material - because steel and concrete don’t float!

ERMCO


Floating wood

HMS Bounty

replica (1960)

55 m longPhoto courtesy: Inverclyde Views

Floating steel

“Seawise Giant”

( 2005)

458 m longPhoto courtesy: marine insight

Floating concrete

2nd WW “Mc Closkey” ships

HMS Talbot (1943 – 1945)

103 m longPhoto courtesy: marine insight

THE REAL WORLD

ERMCO


Comparing materials

The world’ largest

“floating dock” made of

steel and (lightweight)

concrete

Genoa, 1980

Turkey, 2007Photo courtesy: Il Secolo XIX

Floating steel AND

concrete

ERMCO


As « …the upward buoyant force exerted on a body

immersed in a fluid is equal to the weight of the fluid

the body displaces…” the “specific weight”

(weight for unit volume) of timber is lower than the

specific weight of water, those of concrete and steel

are higher.

water = 1,0 concrete = 2,3-2,4 steel = 7,85

REMEMBER: any comparison based on « inherent »

properties of materials is always misleading

THE REAL WORLD

Archimedes

287- 212 B.C.

ERMCO


18

CONTENTS


2. WHY CONCRETE?

3. COMPARING MATERIALS: MYTHS AND FACTS

4. THE “FUNCTIONAL UNITS”

ERMCO


THE FUNCTIONAL UNITS

The good (and only) questions should then be:

• what materials are used for?

• what FUNCTION, what PERFORMANCES are required

from ELEMENTS built with these materials?

…moving a given quantity of goods by sea,

…supporting a given load,

…improving living comfort for people …….

The answer identifies a ship, a slab (or beam or column),

a building …..in general a « FUNCTIONAL UNIT »

ERMCO


CONCLUSIONS

As comparisons cannot be based on material properties

alone, in the case of “functional units” like structural

elements what methodology should be applied?

The “DDC rule”

Define – Design - Compare

ERMCO


THE DDC RULE

1) DEFINE a functional unit, “boundaries” included;

2) DESIGN the f.u. using a reference material at its

maximum performance, then re-design the same f.u.

with other materials to match that performance;

3) COMPARE the different solutions considering the

three “pillars” of sustainability..

ERMCO


22

CONTENTS


2. WHY CONCRETE?



5. THE THREE PILLARS OF SUSTAINABILITY

ERMCO


23

Any “sustainable development” assessment is based on

three “pillars”

1) Social: in very broad terms, everything related

to citizens’ welfare, protection and safety

2) Economic: the overall cost of a solution

3) Environmental: impact on the environment

How these pillars are taken into account when dealing with

“functional units” made by construction materials ?

The main rule of sustainability: “DO MORE WITH LESS”

THE « PILLARS» OF SUSTAINANBILITY

ERMCO


1) THE SOCIAL PILLAR: SAFETY

Let’s consider a component of a building:

• a column of constant area A (short, no buckling to be fair to timber),

• designed to support a given axial force NEd (bending not considered)

according to the relevant European design standard (Eurocode).

The maximum axial force the column may support is given by

the product: area A x design strength fd

Timber “t” NRdt = At ftd = At ftk /t

Steel “s” NRds = As fsd = As fsk /s

ERMCO


Designers’ « degrees of freedom»

As concrete, steel/timber elements have a number of strength classes

Steel: 4 S235 S275 S355 S450

Steel and timber designers have 3 “degrees of freedom” :

1) section shape (rectangular, circular…)

2) section area A

3) material design strength fd

Timber: 12

ERMCO


NRdrc = Ac fcd + As fyd

Five “degrees of freedom” :

1) shape

2) section area Ac

3) conc. strength class fcd

4) ordinary steel area As

5) steel strength class fyd

Reinf.concrete «degrees of freedom»

Q: How can wood and steel, two “homogeneous” (= 1

single component) materials be compared with an

“inhomogeneous” (= 2 components) one as r. concrete?

ERMCO


NRd,rc = Ac fcd + As fyd = Ac fcd [1 + (As fyd)/ (Ac fcd)]

NRd,rc = Ac fcd [1 + (fyd/fcd)] l = As/Ac

NRd,rc = Ac (fcd ac,s) ac,s = 1 + l (fyd/fcd)

Reinforced concrete designers’

« degrees of freedom»

ac,s > 1 is the “ (concrete) strength enhancement coefficient”

a number which transforms a 2-component material into an “ideal”

homogeneous one - so comparison with other materials is possible

ac,s depends on the “quantity” (% of reinforcement) and the “quality”

(the design strength) of both concrete and steel

ERMCO


NRdrc = Ac (ac,s fcd ) ac,s = 1 + l (fyd /fcd) l = As/Ac

Reinforced concrete designers’

«degrees of freedom»

fyd = 500/1,15 = 435 MPa

+ 95% +62% +43%

ERMCO


2) THE ECONOMIC PILLAR

TOTAL COST = QUANTITY USED X UNIT COST

Costs are always related to LOCAL conditions (availability,

competitive pressure, local culture and traditions….)

(Local) unit costs of construction materials (and of finished

works) are usually PUBLIC available in producers’ or

Chamber of Commerce “street” price lists, to be used by:

- architects and engineers, to prepare tenders for works,

- public authorities, to control tenders’ offers

ERMCO


Price lists on the Internet - without

infringing competition rules!

ERMCO


Construction materials costs may be:

• either at the “(construction) gate” or “put in place”;

• by weight (€/kg – steel) or volume (€/m3– concrete, timber)

(Cost by weight) x (material specific weight) = cost by volume

(€/kg x kg/m3) = €/m3

For a given functional unit, costs in the following are:

• at the construction gate;

• on the basis of the cost “c” per unit volume (€/m3) of

each real or “homogeneous” material.

Price lists on Internet - without

infringing competition rules!

ERMCO


The (r.c.) cost enhancement coefficient

As for the load capacity, the cost crc of 1 linear meter of reinf.

concrete depends by the volumes (A x 1) i.e. by the areas of

- concrete Ac

- reinforcing steel area Asl + Asw (Asl = longitudinal

reinforcement, Asw = transverse reinforcement - stirrups

and connectors)

- each multiplied by their unit costs “cc” and “crs”:

ERMCO


The (r.c.) cost enhancement coefficient

Gross concrete area Ac total reinforcing steel area As ,

Unit costs by volume: concrete “cc”, steel “crs”, reinforced concrete “crc”:

Crc = crc Ac = Ac cc + Asl+sw crs = Ac cc [1 + t (crs/cc)]

crc = cc [1 + t (crs/cc)] = ac,c cc t = (Asl+ Asw) /Ac

ac,c > 1 is the concrete cost “enhancement coefficient”, similar to the

concrete strength enhancement coefficient ac,s = 1 + l (fyd/fcd).

It transforms the cost of a inhomogeneous material into the

cost of an “ideal” homogeneous one.

Even if t > l , the two coefficients are formally similar

F. Biasioli - Sustainability and costruction materials: myths, facts and fallacies

ERMCO


THE ENVIRONMENTAL PILLAR

Among the many environmental aspects of sustainability,

communication mainly refers to CO2 emissions into air.

“ The cement production process emits CO2 ! ”

“Cement is a major source of CO2 !”

SO WHAT?

1) The most relevant source of CH4, even worse than CO2, is

CATTLE: are we planning to kill all the world’s sheep? and

cows? and pigs?

2) We don’t build CEMENT (or aluminium, or steel): we

build functional units using (a limited quantity of) cement.

ERMCO


THE EMBODIED CO2

For materials, information about CO2 may be (and is

usually given) as

ECO2 = “Embodied” CO2

expressed as (kg CO2/kg material).

ECO2 data are usually PUBLIC available

- in specific databases,

- in products’ specific information.

ERMCO


THE EMBODIED CO2

ECO2 data depend on:

a) the constituents of each construction material;

b) their production process, transport and energy included

c) their Life Cycle Assessment (LCA)

ECO2 data are (today) available in a non-standard way.

WHAT A MESS!

This is the main reason why we need standardized

materials’ EPDs - Environmental Product Declarations

(work in progress in CEN TC350).

ERMCO


EPDs from Germany….

ERMCO


from Norway….

ERMCO


from Italy….

ERMCO


The (r.c.) ECO2 enhancement coefficient

As for strength and cost, in the case of r.c . the unit embodied CO2

eCO2rc depends from the concrete and steel areas Ac , As and their two

unit values “eCO2c” and “eCO2s” which can be taken from their EPDs

ECO2rc = eco2rcAc = Ac eCO2c + As eCO2rs

eCO2rc = eCO2c[1 +t (eCO2rs / eCO2c)] = aC,CO2 eco2c t = (Asl+ Asw) /Ac

aC,CO2 = 1 + t (eCO2rs / eCO2c)

ac,c02 > 1 is the concrete “eCO2c enhancement coefficient”

(formally) similar to the “strength” and “cost ” coefficients

ERMCO


The r.c. “enhancement coefficients”

STRENGTH ac,s = 1 + l (fyd/fcd)

COST ac,c = 1 + t (crs / cc)

ECO2 ac,co2 = 1 + t (eco2rs / eco2c)

For the functional unit “column” the coefficients are:

Similar formulae may be developed for other r.c.

“functional units” - slabs, beams…

We have covered the three “pillars” of sustainability

ERMCO


43

CONTENTS


2. WHY CONCRETE?




5. PRICE VS PERFORMANCE

ERMCO


Humans are “economic animals”

When you buy something (in a shop, at the restaurant, at the

market) you ALWAYS makes a (conscious or inconscious)

PRICE vs. PERFORMANCE EVALUATION

“Eaten well, good price!” “Pay two, take three”

“ Rabatt! Special sales!” “Incredible offer!”

This should be the attitude of engineers, construction

companies and decision makers!....but rarely it is.

PRICE VS PERFOMANCE

ERMCO


45

Numbers may be

different in different

countries but

results don’t

change too much

t = (Asl+ Asw) /Ac > l

For reinforcing steel :

cs = 1,0 € /kg

cs = 7850 €/m3

C20/25 C30/37 C40/50 C20/25 C30/37 C40/50

fck 20 30 40 20 30 40

fcd 13,3 20,0 26,7 13,3 20,0 26,7

a c a c fcd (N/mm2)

1,0% 1,32 1,21 1,15 17,5 24,1 30,7

1,5% 1,47 1,31 1,23 19,7 26,2 32,8

2,0% 1,63 1,41 1,31 21,8 28,3 34,8

2,5% 1,79 1,52 1,38 23,9 30,4 36,9

3,0% 1,95 1,62 1,46 26,0 32,4 38,9

cc (€/m3) 60 75 90

a cc

1,0% 1,70 1,61 1,53 102 121 138

Cost 1,5% 2,06 1,92 1,80 123 144 162

2,0% 2,41 2,23 2,06 144 167 186

2,5% 2,76 2,53 2,33 166 190 210

3,0% 3,11 2,84 2,59 187 213 233

eCO2 (kg/m3) 290 385 480

1,0% 1,22 1,16 1,13 354 448 542

1,5% 1,33 1,24 1,19 386 479 573

2,0% 1,44 1,33 1,26 418 511 604

2,5% 1,55 1,41 1,32 450 542 635

3,0% 1,66 1,49 1,39 481 574 666

Concrete class, fck, fcd (N/mm2)

Embodied

CO2

a cc cc (€/m3)

a cC02 eCo2c (kg/m3) a cCO2

Strength

t

l

t

PRICE VS PERFOMANCE

ERMCO


“Tuning” the r.c. solution

IN THIS COUNTRY increasing the concrete strength class:both cost and embodied CO2 reduce!

Architects and engineers should be made aware!

cc (€/m3) C20/25 C30/37 C40/50 C20/25 C30/37 C40/50

1,0% 5,8 5,0 4,5 130% 112% 100%

Cost 1,5% 6,3 5,5 4,9 140% 122% 110%

2,0% 6,6 5,9 5,3 148% 132% 119%

2,5% 6,9 6,3 5,7 155% 140% 127%

3,0% 7,2 6,6 6,0 160% 146% 134%

eCO2 (kg/m3) C20/25 C30/37 C40/50 C20/25 C30/37 C40/50

1,0% 20,2 18,5 17,6 118% 108% 103%

1,5% 19,6 18,3 17,5 115% 107% 102%

2,0% 19,2 18,1 17,3 112% 105% 101%

2,5% 18,8 17,9 17,2 110% 104% 101%

3,0% 18,5 17,7 17,1 108% 103% 100%

a cc cc/a c fcd €/(m kN)

a cc/a cCO2 kg/(m kN)

Embodied

CO2

l

l

ERMCO


“Tuning” the solution

The specifier (developer, architect, engineer) may be looking for the minimum cost/strength or the minimum cost /EC02

(or whatever balance between the two he likes!). As a GENERAL RULE, the HIGHER the strength class, the BETTER the r.c. perfomance for COST, SAFETY and the ENVIRONMENT!

Why designers usually DON’T make the best choice in the interest of their client, the general public and the environment? Higher concrete strength class = less f.u. cost , increased durability, less environmental pollution…..

Why? Because we have to TRAIN them!

ERMCO


48

CONTENTS


2. WHY CONCRETE?





6. THE « SUSTAINABLE » COLUMN

ERMCO


NUMERICAL EXAMPLE

Timber: class C30, fc0,k = 23 N/mm2 t = 2,40

fc0,d = fc0,k / 2,40 = 9,6 N/mm2

Section (300x300) mm

NRd = At fc0,d = 90000 x9,6x10-4= 864 kN (86,4 t)

Steel: class S355, fyk = 355 N/mm2 s = 1,05

fyd = 355 / 1,05 = 338 N/mm

Minimum required section:

As = NRd / fyd = 86400/338 = 2555 mm2

Tube (dxs) (168,3 x 5)mm

As = 2570 > 2555 mm2

ERMCO


Concrete: class C30/37, fck = 30 N/mm2

t = 1,50 fcd = fck / 1,50 = 20 N/mm2

Reinforcing steel: class B450C fyk = 450N/mm2

t = 1,05 fyd = fyk / 1,50 = 435 N/mm2

Assuming l = 1,5% acc = 1,31 (+31%)

Ac = NRd /(ac fcd ) = 86400/ (1,31x20) = 4320 mm2

Section (200x200) mm at least four 12 mm diam. bars required

(one in each corner) Asl = 4x113 = 452 mm2

l = Asl/Ac = (452/2002) x 100 = 1,13%

ac = 1 + l (fyd/fcd) = 1+ 0,0113 (435/20) = 1,25

NRd,c = Ac (ac,c fcd) = 40000 x1,25 x 20x 10-4 = 99,6 > 86,4 t

EXAMPLE: COLUMN, NO BUCKLINGPříklad: sloup bez vlivu štíhlosti

ERMCO


In this specific country and for this functional unit, compared

to timber the reinforced concrete solution:

uses 56% less material

occupies 56% less space

costs 76% less

has 154% more ECO2 but

the cost of 1 kg of ECO2

is about 1/10 of the

timber one!

EXAMPLE: COLUMN, NO BUCKLING

units Timber Steel R. conc.

m2 0,09 0,003 0,04

% 100% 3% 44%

m2 0,09 0,02 0,04

% 100% 25% 44%

€/m 27,0 32,3 6,5

% 100% 120% 24%

kg/m 7,2 24,2 18,3

% 100% 336% 254%

€ /kg 3,8 1,3 0,4

% 100% 36% 9%

Element area

Foot area

Cost C

ECO2

C (ECO2)

ERMCO


QUESTIONS

1) In a time of limited resources, how much public

authorities and the society are ready to pay for playing

the CO2 game?

2) Why should we “concrete” people be worried about

discussing CO2 arguments using “concrete”

arguments based on RELIABLE CO2 data?

3) Instead of spending time “scraping the bottom of the barrel”

(“recarbonation”, “recycling”), why not to show to the

people outside how cost effective and environmentally

friendly our (consciously selected) solutions are?

ERMCO


OTHER ARGUMENTS

A number of other good arguments show how effective concrete

solutions are when compared with timber and steel:

• concrete solutions may be a “tailor-made cocktail” of

materials to suit even the most demanding customer’s needs

(no waste!)

• concrete solutions have other inherent relevant performances

(thermal mass, resistance to fire….) at no extra cost!

• ready mixed concrete (and a number of precast products also), is

a nearly ”km 0” product, so contributing to local well-being

….and much more (recarbonation, recycling…)

Let‘s have a look to some of them

ERMCO


54

CONTENTS


2. WHY CONCRETE?






7. CONCRETE IN A « CIRCULAR ECONOMY »

ERMCO


CIRCULAR ECONOMY

Considering their whole LIFE CYCLE - including extraction of raw

materials, production and transport, till to demolition and waste

management - buildings in Europe are responsible for:

• 40% of all energy consumption

• 35% of all greenhouse gas emissions

• 50% of all consumption of raw materials

• 33% of all the water used

ERMCO


How much CO2 is embedded into buildinga may be

evaluated doing a Life Cycle Assessment (LCA)

CIRCULAR ECONOMY

“Model for Life Cycle Assessment of buildings”

pub. 2018

Structural elements of a building contribute

up to 40% of the total CO2 emissions and

beyond 30% for other impacts. Most of

structural elements are made of concrete

http://publications.jrc.ec.europa.eu/repository/bitstream/JRC110082/report_d1_

online_final.pdf

ERMCO


CIRCULAR ECONOMY

For this reason, the EU is moving towards an efficient use

of resources based on «circular flows». The goal is to

achieve zero «Green House Gases» (GHG) emissions by

2050, assessing the role of buildings and related industrial

sectors.

The buildings’ construction and demolition waste sector

is also relevant, being the largest source of waste in

Europe in terms of volume,

90% of buildings’ waste can be re-evalued, although

downgraded to lower value applications.

ERMCO


CIRCULAR ECONOMY

The cement sector has achieved important emission

reduction targets, thanks to investments in innovative

technologies and the use of alternative fuels, replacing

fossil fuels. Data referring to specific emissions for

product unit show:

-12.4% CO2

- 29.4% PM10

- 29.7% NOx

- 32.6% SOx

ERMCO


CIRCULAR ECONOMY

Concrete can be completely recycled at the end of its

life, for the production of new concrete or other

applications such as road foundations.

Buiding Information Modelling (BIM) and innovative digital-

based design methodologies («dexign to reuse») will

contribute to recover concrete from structures.

In this way, in addition to reducing costruction costs, a

fraction of the concrete emedded CO2 will be taken out.

ERMCO


CIRCULAR ECONOMY

Another aspect is the management of ready-mixed concrete

«returned» to the plant, due to excess supply or no-

acceptance at the delivery site. If properly recycled, new

materials are used obtained.

Concrete is an integral part of circular economy,

because it:

- uses waste products (FA, SF) from other chains

- can be completely recycled at the end of its life.

ERMCO


61

CONTENTS


2. WHY CONCRETE?






7. CONCRETE IN A CIRCULAR ECONOMY

8. BEYOND THERMAL MASS: THE «ENERGY STORAGE»

CONCRETE

ERMCO


• In a number of countries a lot of renewable energy

(wind, solar, hydro) is produced today. In a number of

cases the “peak” of production does not match the

“peak” of use

• We are now starting to think how to “store” this

energy (lead batteries, cars, water thanks, moving

loads…..)

• A simple, economic and efficient solution is

to use concrete as an energy storage medium

HOW TO STORE ENERGY?

Renewable electricity and power consumption in Lower Austria

hydro

biomass

sun

Sebastian Spaun | www. zement.at ERMCO 2018 Congress, Oslo 7-8 June

Changes in the energy system

wind

power consumption

ERMCO


64

ENERGY STORAGE IN CONCRETE?

Why concrete for “energy storage”? Because of its excellent suitability for thermal exploitation

extraordinarily high thermal conductivity

high specific weight - about 2,400 kg/m3

> 28 cm

concrete

> 28 cm

bricks

> 10 cm

wood

> 2,5 cm gypsum

plaster board

thermal conductivity λ W/mK 1,8 0,2 0,1 0,2

heat capacity c kJ/kgK 1,0 1,0 2,5 1,1

specific weight ρ 103 kg/m3 2,4 0,8 0,5 0,9

conductibility of temperature a 10-6m2/s 0,8 0,8 0,1 0,2

dynamic penetration depth (T=24h) δ m 0,14 0,09 0,05 0,08

surface related operative thermal capacity χ' Wh/m2K 27 13 12 1

volume related heat capacity C Wh/m3K 667 222 347 263

Thermo-dynamic parameters of building materials

ERMCO


65

reinforcing steel

concrete

Pipe grid (water!)

©Firma Aichinger Hoch- und Tiefbau, NÖ

Component activation of a storey ceiling

ENERGY STORAGE IN CONCRETE

A maximum of thermal comfort

Room on top floor of a passive houseExterior walls facing West and North

Massive construction


The concrete ceiling is almost isotherm

The major part of the heat dissipated from the pipe register flows to thespace underneath the ceiling© Dr. Klaus Kreč

Structure1,0 cm floor covering6,0 cm cement screed3,0 cm footfall sound absorption10,0 cm insulating fills25,0 cm reinforced concrete ceiling

Structure of a standard ceiling

Heat flow between 2 streamlines: 0,2 Wm-

1


No change of the standard ceiling structure!

ERMCO


68

ENERGY STORAGE CONCRETE

Pilot project: massive independent house in Weinviertel (AT)

ERMCO


69


Specific weight concrete: approx. 2 400 kg/m³

Volume related heat storage capacity C: 0,667 kWh/m³K

1 m³ concrete can store a quantity of heat of 2.67 kWh

when heated by 4 K!

1 m² concrete ceiling (0,25 m)

can store 0.68 kWh heat when

heated by 4 K

ERMCO



ERMCO


72


• Realizable without big technical effort and at low cost

• Highest thermal living comfort due to radiant heat

• Energy efficient and healthy cooling!

• Low heating medium temperature and buffer capacity favour

the use of renewable energies

• High cooling medium temperatures favour passive cooling

• The ‘building concrete battery’ is safe and 100 % recyclable

Thermal Building Activation

ERMCO


73

CONTENTS


2. WHY CONCRETE?






7. CONCRETE IN A CIRCULAR ECONOMY

8. BEYOND THERMAL MASS: THE «ENERGY STORAGE»

CONCRETE

9. CONCLUSIONS

ERMCO


CONCRETE TODAY

CONCRETE CAST ON SITE IS

THE

FLEXIBLE

COST- EFFICIENT

ENVIRONMENTAL FRIENDLY

CONSTRUCTION MATERIAL!

ERMCO


75

SUSTAINABILITY

AND COSTRUCTION MATERIALS:

MYTHS, FACTS AND FALLACIES

THANKS FOR LISTENING!

Francesco Biasioli

ERMCO, the European Ready Mixed Concrete Association

MYTHS, FACTS AND FALLACIES - APEB · F. Biasioli - Sustainability and costruction materials: myths,...

Documents

Transcript of MYTHS, FACTS AND FALLACIES - APEB · F. Biasioli - Sustainability and costruction materials: myths,...