Maribor 3 - SCC

8/3/2019 Maribor 3 - SCC

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Definition

Self-compacting concrete, is a concrete that does not need

any external compaction while being poured.

Higher viscosity and thus its higher stability against

segregation or bleeding.

Casting without vibration - reduces the noise


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Objectives

Productivity

Elimination of the use of vibrators Increase the velocity of concrete production,

Reduction of construction costs Development of new pumping and formwork filling

techniques

Ergonomie and environment (vibration)

Problems of blood circulation disturbance

Significative additional load

Noise pollution


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Objectives


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Objectives

Concrete placing in the

Shopping Center structure in

Ferrara-Itlia


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Development of SCC

1986 - Japo - Prof. Hajime Okamura characteristics of SCC

1988 experimental use as a HPC - SCHPC

10 last years - important experiences

In building and bridges constructions, pre-fabrication, etc.

Researchs :- SCC mix design

- Rheology of the paste and mortar

SCCNET - Japo (www.infra.kochi-tech.ac.jp/sccnet/)

Project Brite-EuRam ( 5 pases )

RILEM TC 174 - SCC


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Properties required to SCC

Filling capacity

Segregation resistance

Passing ability

How ?

Reduction of the particles frictions

Reduction of the surface tension Superplasticizers

Optimization of the aggregates skeletton

Use of fine materials (fillers)


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Aggregates Blocking

The risk of aggregates blocking depends:

Reinforcement arrangements

Size and shape of the coarse aggregate

Liquids phase volume

Liquids phase = fine particles up 0,25 mm


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Rheological Properties

Concrete suspension

- segregation resistance

- bleeding resistance- plastic viscosity

Herschel-Bulkley Model

Bingham model


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Universidade daBeira Interior

Portugal

Rheometer BTRHEOM [4] Rheometer BML [8]

Rheometer SchleibingeBT2

Remetros

Rheometer Viskomat NT

Rheometers


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Evaluation of the SCC rheological

properties on site New methods (rheological properties determination )

workability

filling capacity (slump flow test)


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Slump flow test

Diameter Dmx: 650 750 mm

D500mm after 3 a 6 seconds

Verification of the homogenity

of concrete on the border


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Passing Ability

L-box method


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Viscosity

V Funnel method

Relative Velocity

Rm = 10/t t (in seconds)


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Portugal Luiz A P OliveiraII SIMPSIO BERO-AMERICANO SOBRE "CONCRETO ESTRUTURALSetembro 27, 2006, Rio de Janeiro

Sistema de bombagem pelo fundo da forma

New techniques of concrete placing


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The main objectives of this research project can be summarised as follows:

. study the effect and optimisation of the fibberscharacteristics as function of the self - compacting

concrete infill workability and a porous substract.

. study the effect and optimisation of the volume offibbers and the admixture materials to improve

concrete infill fresh and hardened properties.

. study the effect of the volume of fibbers as areplacement and reducing reinforced requirements in

the masonry constructions

. development the models to predict the mechanicalbehaviour of the fibber reinforced concrete infill on the

masonry

POCTI99 Project -Use of fiber reinforced self compactingconcrete for improving the strength and ductility of masonry

constructions


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BEIRA INTERIORUNIVERSITY

CovilhPortugal .

www.ubi.pt

structural masonry is a composite structure subjected

to bending and on plane shear

it is necessary a vertical reinforcement placed in the

block holes

filling with a concrete infill or grout in order to ensure a

composite element.

number of bars can be

reduced or can be possible

the use of other more

effective placing methods

higher viscosity and

higher stability

against segregation or

bleeding

restrict block hole

areas demandsconcrete with

high

flowability or

a self

compacting

concrete.

the use of fiber

reinforced concrete

POCTI99 Project - Use of fiber reinforced self compacting concrete for

improving the strength and ductility of masonry constructions


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BEIRA INTERIORUNIVERSITY

CovilhPortugal . www.ubi.pt

Questions [1] Is the addition of fibers to a SCCdetrimental to its workability

properties?

[2] In what way do various amounts of

fibers affect the rheology of SFRSCC?

[3] Is possible design the SFRSCC by a

simple method?




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BEIRA INTERIOR

UNIVERSITY


MIX DESIGN PARAMETER

PROPOSED

The evaluation of the optimum

mixture fine grading is done by

observation of the mortar ratio inthe fresh concrete

Okamura and JSCEmethods

Proposed parameter

1001

1(%)

mf

afAs

1 = cement unitary proportion, in mass;

f = powder or fine material proportion

in mass;

a = sand proportion in mass,

m = total aggregates (fine + coarse).




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Experimental programs1st serie

Table 1. Characteristics of the fibers and the mixtures compositions

Proportions by weight

(c: cv: a: b)*

Mortar

ratio of

SFRSCC

As (%)

Characteristics of the steel fibers (lf/df)*Vf

(%)

lf

(mm)

df

(mm)

Vf

(kg/m3)

A : 1,00 : 0;5 : 3;75 : 3,65w/cm = 0,38

59 3030

60

0,670,67

0,75

3060

30

1734

31

B : 1,00 : 0,5 : 4,02 : 3,38

w/cm = 0,38

62 30

30

60

60

0,67

0,67

0,75

0,75

30

60

30

60

17

34

31

61

C : 1,00 : 0,5 : 4,56 : 2,24

w/cm = 0,37

73 35

35

60

60

0,55

0,55

0,75

0,75

30

60

30

60

25

50

31

61

* c = cement type I 42,5; cv = fly ash; a = natural sand; b = coarse aggregate (19mm); w/cm = water/cimenticiousmaterials. Polycarboxylate superplasticizer content = 3,25%


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Ajustamentos - mtodo de Okamura e Ozawa

Table 2. Characteristics of the fibers and the mixtures compositions


(c: sf: a: b)*

SP

(%)

Mortar ratio

of SFRSCC

As (%)

Fibers

(%)

lf =38 mm,

df =0,55 mm

(lf/df)*Vf

(%)

A : 1,00 : 0;08 : 1,64 : 1,54

w/cm = 0,38

1,2 63 0 -

B : 1,00 : 0;08: 1,70 : 1,43

w/cm = 0,37

1,4 65 0,5 34,5

C : 1,00 : 0;08 : 1,97 : 1,40

w/cm = 0,38

1,5 68 1,0 69

* sf = silica fume; SP = naphthalene superplasticizer; a = natural sand

with fineness modulus 2,36; b = coarse aggregate 10mm.

Experimental programs2 serie


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With the resulting mixtures, it were measured the fluidity, by the

Slump flow method, and the filling capacities, by L-box Method.

The results are show in the figures 2 and 3.

Experimental results1st serie

400

450

500

550

600

650

700

750

10 20 30 40 50 60 70

(lf / df) * Vf (%)

"SlumpFlow"(m

m

As 59%As 62%

As 73%

Fig. 2: Influence of the mortar ratio in the

fluidity of SFRSCC with different volumes of

steel fibers of different aspect ratio.

0,5

0,55

0,6

0,65

0,7

0,75

0,8

0,85

0,9

0,95

10 20 30 40 50 60 70

(lf / df)*Vf (%)

H2/H1 As 59

As 62

As 73

Fig 3: Filling capacity (L-box) of SFRSCC with

different aspect ratio and volumes of fibers.


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BEIRA INTERIOR

UNIVERSITY


EXPERIMENTALMIX DESIGN

Characteristics of the fibers and the mixtures compositions


(c: cv: a: b)*

Fibers

Volumecontent

(%)

SP

(%)

Mortar ratio

As (%)

(lf/d

f)*V

f

(%)

A : 1: 0.15: 1.78: 1.72

w/cm = 0,400 2.0 63 0

B : 1: 0.15: 2.00: 1.50

w/cm = 0,400,5 2,5 68 34,5

C : 1: 0.3: 2.06: 1.44

w/cm = 0,40

1,0 2.5 70 69,0

D: 1: 0.5: 2.15: 1.35

w/cm = 0,40

1,5 2.5 73 103,6

c = cement type II 32,5; cv = fly ash; a = sand; b = coarse aggregate (19mm),

w/cm = water/powders materials. SP= Polycarboxylate superplasticizer content. Fibers Dramix RC 65/30BP




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BEIRA INTERIOR

UNIVERSITY


Steel fibers reinforcement contributionon the ductility of concrete masonry

The RILEM Task Group 162recommendation about

design method for steel fiber

reinforced concrete

Element with ordinary reinforcement

2

2,

2,50,02

3

bh

lDf

f

BZ

eq

2

3,

3, 50,22

3

bh

lD

f

f

BZ

eq

SFR simplified model of real

stress block




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BEIRA INTERIOR

UNIVERSITY


RESULTSSFRSCC FRESH BEHAVIOUR

Mixtures Slump flow* L box* Funnel

V*

D final

(mm)

T500

(sec)

H2/H1 T40

(sec)

T

(sec)

A 765 100 0.88 - 273

B 735 138 1,00 100 322

C 730 185 1,00 200 402

D 760 102 0.90 213 336

62

64

66

68

70

72

74

0 20 40 60 80 100 120

Fiber ratio (l/d * Vf) in %

Mortarratio(As%)

2,00

2,50

3,00

3,50

4,00

4,50

5,00

0 20 40 60 80 100 120

Fiber ratio l/d*Vf (%)

FlowtimeatVfunnel(sec)

0,0

0,5

1,0

1,5

2,0

2,5

0 20 40 60 80 100 120

Fiber ratio l /d*Vf (%)

Flow

timeT40(sec)




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BEIRA INTERIOR

UNIVERSITY


RESULTSSFRSCC HARDENED BEHAVIOUR

2,eqf 3,eqfMixtureVf

(%)(N/mm2) (N/mm2)

B 0,5 2,98 2,51

C 1,0 6,48 5,84

D 1,5 12,12 6,97

Vf = volume of fibers (%)

0

2

4

6

8

10

12

14

0,0 2,0 4,0 6,0

Deflection at mid-span (mm)

L

oad

(kN)

F0,5

F1,0

F1,5

Load

deflection curves of different fibers volume




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CONCLUSION The major findings of the study are:

First, a simple parameter was proposed to design SCC reinforced

with steel fibers. It was verified that it can be a satisfactory control

parameter of the self-compactibility. Qualitative observations

indicated that a homogenous fibers distribution was given in the

mixtures.

Second, it was found that is possible to obtain the desired self-

compacting properties of the masonry reinforced concrete infill till

1,5% fibers volume. However, the increasing of fibers volume needs

more fine materials or mortar augmentation in the concrete.

Next, the increase of fibers volume is responsible of important

augmentation in the flexural capacity of the SFRSCC.

Finally, it was preview that the contribution carried by the each

0,5% volume fibers addition is very significant and can be appreciate

as an equivalent reinforcement bar area.




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Viaduct SCC with white cement

Technology transfer to construction practice

Errors


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Estudos de reologia em argamassas

www.bfrl.nist.gov

SCC Model

composite: coarse

aggregates + matrix

mortar.

SCC Rheological properties assessment from the

concrete mortar phaseNepomuceno Methodology

(2005)

1 - selection of one mortar family ( fines materials),

2- (Vp/Vs): fines materials and fine aggregates ratio volume

PhD Thesis:

METHODOLOGY FOR SELF-COMPACTING CONCRETE MIX-DESIGN
http://www.bfrl.nist.gov/http://www.bfrl.nist.gov/


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Estudos de reologia em argamassasQuadro 1 Exemplo da folha de clculo desenvolvida para argamassasA tool to find self-compactability


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Portugal

Study of mortar rheology

Slump-flow and V funnel for mortar tests


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Admissible interval of variation for fresh properties of mortar


Mortar fresh properties

0,80

0,90

1,00

1,10

1,20

1,30

1,40

1,50

1,60

1,70

1,80

3,00 4,00 5,00 6,00 7,00 8,00

Gm

Rm

Value proposed

by Okamura

research group

[1,2,3 and 4]

Overlapping of

different

research works

in Japan [11]

Target assumed

in this research

work


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Portugal

Estudos de reologia em argamassas

Mortar fresh properties when Sp/p% increaseswith Vw/Vp constant


0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40

1,60

1,80

2,00

0,00 1,00 2,00 3,00 4,00 5,00 6,00 7,00 8,00 9,00 10,00

Gm

Rm

Increase of Vw/Vp with constant value of Sp/p%

Increase of Vw/Vp

Increase of Sp/p%

Sp/p% = constant

Vw/Vp = cons tant

Target assumed in this

research work


0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40

1,60

1,80

2,00

0,00 1,00 2,00 3,00 4,00 5,00 6,00 7,00 8,00 9,00 10,00

Gm

Rm

Increase of Sp/p % with constant value of Vw/Vp

Increa se of Vw/Vp

Increase of Sp/p%

Sp/p% = constant

Vw/Vp = constan t

Target assumed in this

research work

Mortar fresh properties when Vw/Vp increases withSp/p% constant



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Portugal

With the increasing of Sp/p% and keeping Vw/Vp constantWith the increasing of Vw/Vp and keeping Sp/p% constant


Mortar rheology variation


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Portugal

With adequate Vw/Vp and Sp/p% adjustment


Mortar rheology variation


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Portugal

Study of concrete rheology

Example of the design sheet for concrete


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Portugal

Estudos de reologia em betes

Analysis of rheological parameters

Rheological properties of experimented concretes

Study of concrete rheology


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Portugal

Conclusions

It is possible to use fast tests: slump-flow and flowability test to establish therelation of rheological properties between mortar (Gm, Rm) and concrete (Gc, Rc).

This correspondence will be effective in case of segregation and blocking effect

absence on the mixture observed in the slump-flow and V funnel tests

The interval defined for the rheological parameters of mortar (Gm between 5,3 and

5,9; Rm between 1,14 and 1,30 s-1), the one that correspond, respectively, the

values (Dm between 251 and 263 mm; t between 7,69 and 8,77 s), lead to the

attainment of concrete with the following rheological parameters: (Gc between 8

and 11,25; Rc between 0,5 and 1,0 s-1), the one that correspond, respectively, (Dm

between 600 and 700 mm; t between 10 and 20 s).

The defined mortar rheological properties had disclosed adequate to the

attainment of the intended rheological properties for the concretes mixes.


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SCC Aplications

Slabs 20 x 10 m, e = 15 cm

Colunn

casting

Colunn

surface

Maribor 3 - SCC

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