High performance concrete

EX3 Performance special concrete range

Technical data sheet

High performance concrete 3

2

Hig

h pe

rfor

man

ce c

onc

rete

Hig

h pe

rfor

man

ce c

onc

rete

The development in Romania, over the past

years, of several large scale projects required multiple special demands for concrete. The usual concretes not being able to meet these

needs, there were developed concrete with specific/representative properties adapted to

these types of projects.

High performance concrete General information

Areas of use

Art works: arches, bridges, passages, viaducts,

tunnels, etc.;

High civil or industrial buildings or constructions

High performance concrete is a special concrete,

developed to fulfill certain combinations of performance

and uniformity criteria.

High performance concretes:

• meet some standards more complex in comparison to

those of usual concretes;

• fulfill both the technical and the economic

requirements.

If, in case of usual concretes, traditionally, the

compression resistance is the main required

feature, in case of high performance concretes may

prevail other properties such as the elasticity

module, the resistance to impact/ abrasion, low

permeability, etc..

• .

with special requirements and demands (for

example: curved thin slabs);

• Hydro technical works in aggressive

environments, nuclear constructions;

• Constructions with resistance needs in case

of chemical attack, (for example: agricultural

constructions), where this concrete may

have the purpose of inhibitor agent regarding

the evolution and propagation of bacteria

and the appearance of moulds.

Exposure range (according to CP 012-1:2007) Usually, the high performance concretes respond to all conditions derived from the combination of the exposure

classes, mostly due to their low permeability.

Corrosion due to

carbonation

Corrosion due to

chlorides having

other origin than

marine

Attack of frost -thaw in

saturated status with

water and thawing agents

Chemical attack Mechanical

stress by wear

XC1, XC2, XC3, XC4 XD1, XD2, XD3 XF1, XF2, XF3, XF4 XA1, XA2, XA3 XM1, XM2, XM3

Note: According to tables F1.1 F1.2 of Code of practice for the concrete production CP012-1: 2007, the requirements regarding driven air, the

type of aggregate, the cement type, the surface treating, etc. shall be complied with.

High performance concrete General information

High performance concrete is a special concrete,

developed to fulfill certain combinations of

performance and uniformity criteria.

High performance concretes:

• meet some standards more complex in

comparison to those of usual concretes;

• fulfill both the technical and the economic requirements.

If, in case of usual concretes, traditionally, the

compression resistance is the main required

feature, in case of high performance concretes

may prevail other properties such as the

elasticity module, the resistance to impact/

abrasion, low permeability, etc..

The criteria at the basis of the establishment

of the high performance concrete's

composition are:

• The use of a cement of constant, superior quality

(with high content of silicate tricalcium, low

content of aluminates tricalcium);

• The reduction of the water/ cement ratio below

0.35, using a water reducer strong additive (super

plasticizers of the latest generation);

• The use of some aggregates with high resistance

to crushing and a high elasticity module, paying

special attention to the sizes, the shape, the

texture, the absorption, etc.;

• The improvement of the mineral frame (matrix) by

the addition of ultrafine materials, such as micro-

silica in order to increase the concrete's

compaction

4 High performance concrete

High performance concrete

5

t n a t c pa m o c to u A l u n to e B

Hig

h pe

rfor

man

ce c

onc

rete

Characteristics of high performance concrete

The high performance concrete, in fresh

condition, presents features similar to the usual

concrete. He is framed in the settling classes

S3-S5, having a higher viscosity due to the large

quantity of fine material present in the receipt.

In hardened condition, the high performance

concrete has special features, as it follows:

Resistance to compression

The high performance concrete is mainly characterized

by a high resistance to compression at 28 days and a

significant evolution of this after this age.

Comparatively with the usual concretes, the high

performance concretes present a very high initial

resistance. It must be given a special attention to the

sample taking and testing procedures (including to the

testing equipment), because, at very high resistances, the

standard allowed deflection is high, with negative impact

on the uniformity coefficient. An irregular surface or with

deflections from the flatness of the testing sample may

lead to completely wrong results. Following, there are

presented the evolutions in time of the compression

resistances of the high performance concrete produced

by Holcim Romania.

Term/Class

1 day

7 days

Resistance to compression*

28 days

56 days

90 days

C40/50 40,4 60,67 69,08 69,80 72,59

C50/60 55,07 69,85 75,48 77,23 80,51

C60/75 62,6 79,77 86,87 89,37 89,90

C70/85 73,42 97,07 110,48 112,59 112,94

C80/95 81,5 103,58 116,595 123,6 124,56

C90/105 85,3 107,92 125,29 126,76 127,34

Advantages of high performance concrete

Construction's safety

• High durability/ long life expectancy

• High resistance to compression and extension

• High elasticity module

*Tests performed in lab conditions

Resistance to compression

• High resistance to abrasion – + • Low permeability to water and gas

• Superior resistance to chemical attack

• High resistance to frost-thaw, including in the presence of thawing agents

• Resistance to impact

Flexibility

• Execution of all types of structural elements (pillars, beams, walls, slabs, etc.) – + • Execution of complex architectural works • Execution of thin section elements or of structures with wide openings

Protection of humans and of the environment

• Execution of sustainable constructions by increasing the life duration from 50 to 100

years

• Resistance to bad weather conditions and earthquake – +

• Resistance to explosions

• Inhibition of bacteria evolution and of mould appearance

Resistance to extension

As in the case of usual concretes, the resistance to extension rises together with the resistance to compression,

Class

Resistance to extension 28 days (MPa)

By shear* By bending

Cost reduction

• Reduction of the construction duration/ Rapid construction rhythm

due to initial very high resistances

• Reduction of the volume of concrete – + • Reduction of the cladding quantity

• Wider openings (significant advantage to bridges by reducing the costs with the piles and the afferent

foundations)

but the increase is slower. It must be mentioned that there

is no direct proportional relationship between these

characteristics. Factors such as the shape of the

aggregate, its absorption or the petrography nature may

influence more one of these resistances.

C40/50 4,12 7,2

C50/60 4,29 8,2

C60/75 4,52 8,76

C70/85 5,45 9,45

C80/95 5,84 10,1

C90/105 7,86 10,4

*applied according to EC2 by direct extension = 0,9*fct

6 High performance concrete

High performance concrete

7

C80/95 112,1 43,1 40,9 All these characteristics of high performance concretes collaborate to insure a high durability, respectively a life

C90/105 114,3 42,6 41,1 duration of over 100 years, for the structural class S4.

Hig

h pe

rfor

man

ce c

onc

rete

Hig

h pe

rfor

man

ce c

onc

rete

Elasticity module

The high performance concrete, in comparison

with the usual concrete, has a more obvious

monolith character, and the resistance of the

interface area matrix-aggregate is higher. The

interface's crazing is more reduced, and the linear

portion of the curve effort-deflection is expanded until

a demand which can be even over 85% of the

breaking requirement.

The breaking, usually takes place through the matrix

but also through the coarse aggregate.

Carbonation

The compact structure of high performance concretes

involves a better behavior for carbonation. From the studies

made in collaboration with Bucharest Technical University, it

resulted that the high performance concretes exposed in an

environment rich in 𝐶𝑂2 are practically waterproof to this

agent.

Class concrete

Resistance cube MPa

Elasticity

module experimentally

established

Reference values

EC2

Type of aggregate

Closed surface

The absence of open pores at the surface of high C40/50 67,8 39,5 39,1

Quartzous C50/60 71,4 39,9 39,7

C60/75 84,3 39,9 37,5

performance concrete inhibits the evolution of living

micro- organisms (bacteria, fungus), as well as the

appearance of moulds.

C70/85 101,0 42,6 39,6 Quartzous sandstones

Slow flow

In case of high performance concretes, this feature has

much lower values than for the usual concretes,

especially at the concretes containing superfine silica.

Comparatively with the normal concretes, from a

Contraction

In case of high performance concretes, their total

contraction is similar to that of regular concretes, but

having a different kinetics. The endogenous contraction

may be 2-3 times bigger (because of the very fine micro

structure), while the plastic contraction, of drying, is much

kinetic point of view, the flow settles more rapidly. The slow flow

is inversely proportional with the resistances increase.

smaller due to the low water/cement ratio. The high performance

concretes are very sensible to the rapid evaporation of water in the

first hours, therefore it is extremely important to appropriately

protect/treat the freshly poured/ dismantled surfaces.

*Control value calculated according to Eurocode 2 on the base of the experimental results obtained by compression testing

Permeability

Due to low porosity, t he high performance

concretes have a much reduced permeability. To

classes higher than C60/75, this tends towards

zero even at a pressure of 12 atmospheres.

Resistance to frost-thaw

Contact

Brașov:

121 Zizinului Street, RO500407

Tel: +40 740 110 506

Bucharest Chitila:

423 Chitilei, District 1

Tel: +40 740 110 430

Bucharest Clinceni:

Parcel 10, Tarlaua 43, Clinceni Commune, Ilfov

County; Tel: +40 740 110 430

Bucharest Pantelimon:

Bucharest Ring Road, no. 8, District 2;

Cluj-Napoca:

11 Beiușului Street, RO400394

Tel: +40 740 110 433

Craiova:

401 Râului Street, RO200636

Tel: +40 740 110 438

Oradea:

14/C Borșului Street, RO410605

Tel: +40 752 069 118

Ploiești:

48A Centura de Est Street, RO100187;

Sibiu:

12 Turda Street, RO550052

Tel: +40 754 054 710

Târgu Mureș:

8 Bãneasa Street, RO540199

Tel: +40 747 079 963, +40 757 010 985

Timișoara:

17 Moșniței Road, RO300547

Tel: +40 745 643 708

Due to its dense structure and its reduced water quantity in the system, the high performance concretes have a very good behavior at frost-thaw. Up to the resistance class C55/67, there may appear exfoliations caused by the presence of salt as thawing agent. From the studies

made by Lafarge-Holcim group, it shows that at higher classes, where the concrete contains micro-silica, there were no more exfoliations as following the application of the thawing agents (in 56 cycles of frost- thaw), even in case of not using a driven air additive.

Tel: +40 740 110 430

Bucharest Pipera:

52 Pipera Highway, District 1

Tel: +40 740 110 430

Tel: +40 740 110 553

Satu Mare:

146 Careiului Road, RO440187

Tel: +40 740 110 580

Terms/Class

14 days

Contraction to drying ( ‰)

21 days

28 days

Control value*

C40/50 0,0500 0,1109 0,2377 0,25

C50/60 0,0486 0,1007 0,2181 0,24

C60/75 0,0399 0,0978 0,1920 0,21

C70/85 0,0290 0,1058 0,1674 0,16

C80/95 0,0471 0,0848 0,1435 0,15

C90/105 0,0681 0,1043 0,1399 0,14

OBS: The reference values were calculated on the base of experimentally established resistances, with the formula Ecm=22[(fcm)/10]0,3

and the application of the correction depending on the type of aggregate.

8

Holcim (Romania) S.A.

169 A Floreasca Street

Building B, 7th Floor

District 1, RO 014459

Bucharest, Romania

www.holcim.ro

© 2016 Copyright Holcim (România) S.A.