Concrete with pozzolanic

admixtures: an environmental-admixtures: an environmental-

friendly solutionIng. Tereza Kulovaná

tereza.kulovana@fsv.cvut.czIng. Eva Vejmelková Ph.D., Ing. Dana Koňáková, Ing. Martin Keppert Ph.D., Prof. Ing.

Robert Černý, DrSc

Department of Materials Engineering and Chemistry,Czech Technical University in Prague, Czech Republic

Outline:

• Introduction

• Ceramic powder and Natural zeolite

• Used materials

• Experimental methods• Experimental methods

• Experimental results

• Conclusions

Why use additives in concrete?

• Reduction of energy consumption and CO2

emissions

• 1 ton of cement = about 660 kg CO2

• Cheaper prices of binder in concrete• Cheaper prices of binder in concrete

• Use of secondary raw materials

• Improvement of the properties of concrete

Ceramic powderSuitable raw materials for ceramic powder

– Cracked or broken ceramic fragments

– Roof tiles ground

– Damaged brick

– Bricks from demolition

– Heluz (CZ)

Chemical composition

of applied materials

[%]

SiO2

63.45

Al2O

313.98

Fe2O

35.39

TiO2

0.77

CaO 8.18

MgO 4.5

K2O 2.43

Na2O 0.9

SO3

0.1

Natural zeolite• Type of aluminosilicate mineral material containing large

quantuties of reactive SiO2 and Al2O3Zeocem (SK)

Chemical composition

of applied materials

[%]

SiO2

66.84

Al O 13.98Al2O

313.98

Fe2O

33.33

TiO2

0.37

CaO 6.71

MgO 0.59

K2O 8.13

Na2O 0.85

SO3

-

Composition of studied concretes

Component [[[[kg/m3]]]] CR CZ 10 CC 10 CZ 20 CC 20 CZ 40 CC 40

CEM 42.5 R 484 436 436 387 387 305 305

Natural zeolite 0 48,4 - 96.8 - 179.2 -

Ceramic powder - - 48.4 - 96.8 - 179.2

Aggregates 0-4 mm 812 812 812 812 812 812 812

Aggregates 8-16 mm 910 910 910 910 910 910 910

Plasticizer Mapei

Dynamon SX5.3 5.3 5.3 5.3 5.3 5.3 5.3

Water 172 194 160 221 160 244 160

•Amount of used water was determinad based on the same consistence of all studied mixture. •The measurement of material parameters of hardened concrete was done after 28 days of curing in water• It took place in a conditioned laboratory at the temperature of 22 ± 1°C and 25-30% relative humidity

Experimental methodsBasic physical properties

• Bulk density ρ [kg.m-3]

• Matrix density ρmat [kg.m-3]

- Measured using the water vacuum saturation method

Open porosity Ψ [% ]• Open porosity Ψ [% ]

- Determinated by the water vacuum saturation method

The samples for determination of basic physical properties had size 50 mm cubes.

mw water saturated sample, md dry sample, V volume of the sample, ρl density of water

Experimental methodsWater transport properties

Water vapor transport properties

• Water vapor diffusion permeability δ [s]

• Water vapor diffusion coefficient D [m2.s-1]

• Water vapor diffusion resistance factor µ [-]• Water vapor diffusion resistance factor µ [-]

- Measured using the dry cup and wet cup method

The samples for determination of water vapor transport properties had size 150x150x20 mm

Experimental methodsWater transport properties

Liquid water transport properties

• Moisture diffusity К [m2.s-1]

• Water absorption coefficient A [kg.m2.s-1/2]

- Measured using a water vapor sorptivity experiment- Measured using a water vapor sorptivity experiment

The samples for determination of liquid water transport properties had size 100x100x20 mm

Experimental methodsThermal properties

• Thermal conductivity λ [W.m-1.K-1]

• Specific heat capacity c [J.kg-1.K-1]

- measurement based on analysis of the temperature response of the

analyzed material to heat flow impulse

The samples for determination of thermal properties had size 70 mm cubes.

Experimental methodsMechanical properties

• Compresive strength [MPa]

- measurement by the hydraulic testing device

- test performance according to ČSN EN 12390-3

The samples for determination of mechanic properties had size 150 mm cubes

Experimental resultsBasic material properties

HPCρρρρ ρρρρ

matψψψψ

[kg.m-3] [kg.m-3] [%]

CR 2244 2590 13.4

CZ 10 2194 2601 15.7CZ 10 2194 2601 15.7

CZ 20 2132 2601 18.0

CZ 40 2036 2623 22.4

CC 10 2420 2730 11.4

CC 20 2370 2720 12.8

CC 40 2330 2700 13.9

Experimental resultsWater transport properties

HPCA к

[kg.m-2.s-1/2] [m-2.s-1]

CR 0.0086 4.28E-09

CZ 10 0.0096 3.92E-09CZ 10 0.0096 3.92E-09

CZ 20 0.0153 7.42E-09

CZ 40 0.0317 20.8E-09

CC 10 0.0067 3.79E-09

CC 20 0.0077 3.83E-09

CC 40 0.0101 6.23E-09

Experimental resultsWater vapor transport properties

HPC

Dry cup 5/50% Wet cup 97/50%

D D

[m2.s-1] [m2.s-1]

CR 2.18E-07 2.64E-07

CZ 10 2.82E-07 3.34E-07

CZ 20 3.92E-07 4.91E-07

CZ 40 6.49E-07 8.95E-07

CC 10 2.65E-07 3.20E-07

CC 20 2.87E-07 4.34E-07

CC 40 3.06E-07 6.41E-07

Experimental resultsThermal properties

HPCλλλλ c

[W.m-1.K-1] [J.kg-1.K-1]

CR 1.62 738

CZ 10 1.51 732

CZ 20 1.39 729

CZ 40 1.16 706

CC 10 1.53 678

CC 20 1.39 729

CC 40 1.53 783

Experimental results (VUT Brno) Mechanical properties

50

60

70

80

90

Compressive strength

after 28 days [MPa]

Compressive strength

0

10

20

30

40

50

CR CZ 10 CZ 20 CZ 40 CC 10 CC 20 CC 40

Compressive strength

after 360 days [MPa]

Conclusions

Natural zeolite and Ceramic powder can be considered as an

environmental friendly binder with a potential to replace a

part of Portland cement in concrete in building industry

Dosage must be carefully considered!• The mechanical and liquid water transport parameters were satisfactoryThe mechanical and liquid water transport parameters were satisfactory

up to the 20% replacement amount for both pozzolanic materials

• The results of measuring water vapor transport parameters were within an

expected range.

• Thermal parameters were acceptable for all studied mixes

Optimal amount is 20%

This research has been supported by the Czech Science

Foundation under project No P104/12/0308 and under Foundation under project No P104/12/0308 and under

project SGS13/165/OHK1/3T/11

Thank You for Your attention!