Tests der Wirkung von PCE-Fließmitteln auf Stoffe für ... Ressourcen-effizienten, nachhaltigen...

Dr. J. Juhart 111.03.2015 Rheo-Kolloquium Regensburg

Tests der Wirkung von PCE-Fließmitteln auf Stoffe für Ressourcen-effizienten, nachhaltigen Beton

Effect of PCE-Superplasticizers on Powdersfor Eco-Concrete

Institute of Technology and Testing of Building Materials

Institute of Applied Geosciences

Laboratory for Particle Analysis (RCPE)Graz University of Technology


Motivation Climate Protection and Sustainable Development

N2O

CH4

CO2

Quelle: IPCC: Climate Change 2007: Synthesis Report

Cement production causes ~ 5% of world wide CO2-emission [Quelle: VÖZ]

Concrete demand worldwide ~ 7 billion m³/year [KIT 2012]


Development of Eco-concrete

0%

33%

67%

100%

133%strength(fcm,28d)openporosityGWP

PEI

• reduction of GWP and PEI by - 10-30% is possible

• equal concrete performance


water layer

cement

interstitial

water

normal paste

Same workability/strength/ durabilityof eco-concrete and normal concrete

+ superplasticizerwater layer thickness

micro filler

+ superplasticizerwater layer thickness

eco-fillermicro filler

filled voids w/b-ratio e.g. HSC+ “eco-filler”CEM-clinker (w/c )

„eco“-concrete

Packing Optimization & Effect of Fillers


Flowability of Different Powders

Spread flow test

Which SP do you recommend for eco-concrete and what performance will we reach with different fine powders ?


Superplasticizers PCE

Quelle: SIKA Produktbroschüre

PCE ca. 10 nmCEM Ø ca. 10 µm

superplasticizer [PCE] application

‐SP 55 ready‐mixed concreteSP 108 ready‐mixed concreteSP 109 precast concreteSP 110 precast concreteSP 144 precast concreteSP 147 precast concreteSP 170 precast concreteSP 182 precast concrete

bulk density PCE content (solid)

g/cm³ M.%1,07 301,08 291,09 401,06 301,06 281,06 301,06 251,07 30


Powders

Portland Cement d50 = 7,5 µmMicro-fillers d50 < 4 µmEco-fillers 5 µm < d50 < 15µm

type true densityρ0

grain sized50

location parameter x’

slopen

Blaine‐ value

water demand (MEM) Vws/Vp

sensitivity to addition of waterEp

GWP PEI

g/cm³ µm µm ‐ cm²/g ‐ ‐ kgCO2/t MJ/tcem I 52,5 R 3,14 7,50 8,50 0,90 5110 0,92 0,0041 831 4030quartz eco 2,65 13,80 18,60 1,00 4640 0,85 0,0026 41 1338quartz micro 2,65 3,26 4,60 1,10 (12680) 0,83 0,0005 57 1788microsilica 2,20 0,20 (34908) 1,28 0,0033 (0) (0)limestone micro 2,73 2,20 3,50 1,20 9314 0,61 0,0015 36 1006limestone eco 1 2,70 9,00 15,80 1,20 5630 0,59 0,0028 25 717limestone eco 2 2,70 12,00 20,40 1,00 3689 0,69 0,0026 25 717dolomite micro 2,90 3,30 4,30 1,30 8300 0,85 0,0030 36 1006dolomite eco 2,86 15,00 33,50 0,80 2962 0,61 0,0021 25 717

inert stone powders

fact

or 1

/20


Ep, quartz

Ep, limest.

0 100 200 300 400

spread flow [mm]

cement micro-filler (limestone) eco-filler (quartz)

no flow

Water Demand and Flowability of PowdersNew combination-method “MEM-ST”

Water demand for certain spread flow

Vwf/Vp

Ep,cem

Ep,quartz

Ep,limestone

„MEM“

minimumwater

demand

Vws/Vp

• Mixing energy method (MEM) • Spread flow test ST (Okamura)

water demand at saturation (Vws/Vp) ≙ void content water demand for certain spread flows (Vwf,i/Vp)


Sequence of Testing of Water-Powder mixes with SP

• water/powder mixes at minimum water demand (MEM) constant starting consistency

• addition of superplasticizers / mixing

spread flow tests rheometer test

p

sPCE

powder

solidPCE

Vm

Vm

dosageSP __


100

150

200

250

300

350

400

450

500

0,00% 0,25% 0,50% 0,75% 1,00% 1,25% 1,50%

spread

flow

[mm]

mPCEsolid/VP [%]

cem I 52,5 R; d50=7,5µm

SP 108 ‐ LC

SP 144 etc. ‐ HC

Results


Results

100

150

200

250

300

350

400

450

500

0,00% 0,25% 0,50% 0,75% 1,00% 1,25% 1,50%

spread

flow

[mm]

mPCEsolid/VP [%]

cem I 52,5 R; d50=7,5µm

SP 108 ‐ LC

SP 144 etc. ‐ HC


Results

100

150

200

250

300

350

400

450

500

0,00% 0,25% 0,50% 0,75% 1,00% 1,25% 1,50%

spread

flow

[mm]

mPCEsolid/VP [%]

cem I 52,5 Rlimestone eco 1limestone eco 2; d50=12,0µm

; d50=7,5µm; d50=9,0µm

SP 108 ‐ LC

SP 144 etc. ‐ HC


Results

100

150

200

250

300

350

400

450

500

0,00% 0,25% 0,50% 0,75% 1,00% 1,25% 1,50%

spread

flow

[mm]

mPCEsolid/VP [%]

cem I 52,5 Rquartz ecolimestone eco 1limestone eco 2

; d50=13,8µm

; d50=12,0µm

; d50=7,5µm

; d50=9,0µm

SP 108 ‐ LC

SP 144 etc. ‐ HC


Results

100

150

200

250

300

350

400

450

500

0,00% 0,25% 0,50% 0,75% 1,00% 1,25% 1,50%

spread

flow

[mm]

mPCEsolid/VP [%]

cem I 52,5 Rdolomite microdolomite ecoquartz ecolimestone eco 1limestone eco 2

; d50=13,8µm

; d50=3,3µm

; d50=12,0µm

; d50=7,5µm

; d50=9,0µm

; d50=15µm

SP 108 ‐ LC

SP 144 etc. ‐ HC


Results

100

150

200

250

300

350

400

450

500

0,00% 0,25% 0,50% 0,75% 1,00% 1,25% 1,50%

spread

flow

[mm]

mPCEsolid/VP [%]

cem I 52,5 Rdolomite microdolomite ecoquartz ecolimestone microlimestone eco 1limestone eco 2

; d50=2,2µm

SP 108 ‐ LC

SP 144 etc. ‐ HC

; d50=13,8µm

; d50=3,3µm

; d50=12,0µm

; d50=7,5µm

; d50=9,0µm

; d50=15µm


Results

100

150

200

250

300

350

400

450

500

0,00% 0,25% 0,50% 0,75% 1,00% 1,25% 1,50%

spread

flow

[mm]

mPCEsolid/VP [%]

cem I 52,5 Rdolomite microdolomite ecoquartz ecolimestone microlimestone eco 1limestone eco 2

; d50=2,2µm

SP 108 ‐ LC

SP 144 etc. ‐ HC

; d50=13,8µm

; d50=3,3µm

; d50=12,0µm

; d50=7,5µm

; d50=9,0µm

; d50=15µm

limestonequartz

cement


Rheometer –Tests

assumption: linear Bingham flow-curve

torque

[mNm]

rotational frequency [1/min]

rel. viscosity η

rel. yield value M0

Vmeasuring ~ 15 ml

water/powder mixes with constant starting consistency(near minimum water demand, spread flow= 130 mm)

addition of superplasticizers + external pre-mixing


Specifications Rheometer Measurements

0

50

100

150

200

250

300

0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450

rotatio

nal frequ

ency [1

/min]

testing time [sec]

test‐profile (rate of shear history)pre‐shearing data aquisition

measurement points


0

2

4

6

8

10

0 50 100 150 200 250

torque

[mNm]


dolomite powder "eco"min. water demandSP_144 0,025%SP_144 0,15%

0

2

4

6

8

10

0 50 100 150 200 250

torque

[mNm]


CEM I 52,5 Rmin. water demandSP_144 0,025%SP_144 0,4%

Results Rheometer – flow curves

Yield value min. water demand M0,mwd~ const.for all water/powder mixes

SP saturation SP saturation

M0 yield value atmin. water demand

viscosityviscosity

M0 yield val. atmin. waterdemand

mwdMMMrel

,0

00.


0,0

0,2

0,4

0,6

0,8

1,0

1,2

0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75

rel. M0 [‐]

mPCE_solid/Vp [%]

SP 144‐HC

CEM I 52,5 Rlimestone eco 1dolomite ecodolomite microlimestone microquartz ecomicrosilica

0,0

0,2

0,4

0,6

0,8

1,0

1,2

0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75

rel. M0 [‐]

mPCE_solid/Vp [%]

SP 108‐LC

CEM I 52,5 Rlimestone eco 1dolomite microdolomite ecolimestone microquartz ecomicrosilica

Results Rheometer –yield stress (rel. M0) vs. SP-dosage


Results Rheometer – rel. M0 vs. rel. η

0,0

0,2

0,4

0,6

0,8

1,0

1,2

0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75

rel. M0 [‐]

mPCE_solid/Vp [%]

SP 108‐LC

CEM I 52,5 R

limestone eco 1

dolomite micro

dolomite eco

0,0

0,2

0,4

0,6

0,8

1,0

1,2

0,00 0,25 0,50 0,75 1,00 1,25 1,50 1,75

rel. η [‐]

mPCE_solid/Vp [%]

SP 108‐LC

CEM I 52,5 R

limestone eco 1

dolomite micro

dolomite eco


0

2

4

6

8

10

12

0 50 100 150 200 250

torque

[mNm]


microsilica

SP_108‐LC 0,05%

SP_144‐HC 0,05%

min. waterdemand

Influence of PCE-SP on Microsilica (d50~0,2µm)

+ SP


Summary and Conclusion

• investigations by spread flow test and Rheometer

• SP-demand of CEM I > SP-demand of most stone powderswith similar fineness to CEM I(differs for quartz-dolomite-limestone)

• viscosity of CEM I mixes > viscosity of most stone powder mixes of similar fineness

• „SP-demand“ ↗ with increasing fineness of powdersincrease of yield stress & agglomeration of PCE with very fine powders observed

• for stone-powders: only small differences between SP-HC and SP-LC

• spread flow over time:decrease for cement (SP-HC ) > decrease for stone powders(almost no decrease over time for stone powders with all SP)

• estimation of spread flow of powder-mixes is possible when knowing the SP-demand of single ingredients (by summing up the weighted spread flows)

• Outlook: testing of the effect of SP on powders in pore solution of cement-limes is recommended (pre-tests show a big influence of pH-value and ions in pore solution on the interaction of powders and pore solution)


[email protected]

Thank you for your attention!

Co-authors: Claudia Nickel, Prof. J. Tritthart

Data based on student works of D. Borovina, A. Schönauer, C. Maier, TU Graz 2014/2015

Date post:	11-May-2020
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