HYDROPHOBIC IMPREGNATION CONCRETE STRUCTURES

STATE OF THE ART WITHPLANISEAL WR-LINE

Paul Stavem– Technical Manager Mapei Nordic/Baltic

– Background• Cand.Scient Chemistry University of Oslo

• Boardmember of Norwegian Assosisation ofConcrete Renovation (NFB)

• National member of CEN EN 1504-2/4

• Leacher - national courses for concrete repair

• Author - textbooks and other publications

Short introduction

Why concrete structures degenerates in summertime:

Why concrete structures degenerates in wintertime:

• Erosion• Impact• Fatigue• Overloads• Movements• Explosions• Vibrations

• Biological activity (bacteria) • Aggressive chemicals (hydrochloric acid, sulfuric acid)• ASR-reactions

• Freeze/thaw cycling• Thermal cycling• Crystallisation of salts• Creep• Erosion• Wear

Årsaker tilskader på

betong

Reasons for concrete damages

Chemical

Mechanical

Fire

Physical

The reasons why concrete breaks down:

• w/c -ratio• Type of cement and amount• Admixtures• Relative humidity in concrete• Temperature• CO2 consentration

• Chorides added during casting• Seawater• Deiceing salts• Other

Carbonatisation

Reasons for rebar corrosionChlorides

Electrochemical degeneration

Reasons why for concrete breaks down:

Concrete Structures – Close up on marine structures

Cl- (%cement)= Cl- (%concrete)*Density of concrete/amount of cement

If 350 kg cement/m3 -> 4.28 wt% Cl- of cement

Figure from Finn Fluge – Marine Chlorides / 2001 Tromsø

The sad truth….

• Facts;– Chlorides in concrete will causes rebar corrosion

– Repair of damages caused by chloride initiated corrosion have a very high cost

• Actually only two possible strategy's:– Leave as it is and schedule for repairworks within 10-20 years

– Make correct preventive actions, and save money by avoiding high cost repair

• The different solutions

– Cathodic protection

• eg. Mapeshield systems

– Surface treatment systems

• Coating systems – eg. Mapelastic

– eg. Elastocolor-system

• Hydrophobic impregnation – eg. Planiseal WR-line

HOW TO PREVENT THIS SITUATION

• Migrating hydrophobic products– Makes the surface layer of the concrete hydrofobic!

– Protect the concrete from all types of damages where water is involved:

» Corrosion caused by chlorides

» Frost/thaw cycles

» ASR-reactions

– Does not change the appearance of the concrete

– Does not alter the transpirability of the substrate

HYDROFOBIC PLANISEAL WR-LINE

• The key is to understand how hydrofobicimpregantion of concrete really works?

Planiseal WR-line

θθ

Hydrophobic

material θ > 90º

θ

θ

Hydrophilic

materialθ < 90º

θ

θ

θ = 90º

Hydrophobic propreties for Planiseal WR-line

θθ

Hydrophobic

material θ > 90º

θ

θ

Hydrophilic

materialθ < 90º

θ

θ

θ = 90º

Material related:• Type of material

• silane/siloxane• Active content

• % active material• Amount applied• Contact time

Know-how is the parameter for success!

Substrate related:• Concrete quality• Time of application• Moisture content

«Protective effect»

«Durability»

• Type of silane/siloxane

– Silane with:– “small” molecule -> high penetration

– “slow” reaction speed -> higher penetration

– “low” evaporation speed-> higher penetration

– Siloxane with:– large molecule -> less penetration

– higher bleeding effect -> less transpirability

» In general less suitable for long term protection of concrete

Planiseal WR-line – Type of silane/siloxane

The optimal compromise is important

Planiseal WR-line – silane reactions with concrete

- Chemical reaction with alkaline concrete- No film means no detachments possible

• % Active matter• For high quality concrete

– Higher amount -> better penetration

• For “low” quality concrete

– Less proven effect

• Amount of material applied– In general more material applied -> better

penetration

– But depends on

» concrete absorption capability

» reaction/evaporation speed (material dependent)

Planiseal WR-line – Active content

• Contact time– Penetration depth will always depend on:

» concrete absorption capability (substrate dependent)

» reaction/evaporation speed (material dependent)

– Increased contact time and reduced evaporation speed:

» Better penetration

Planiseal WR-line – Contact time

Liquid

Cream

Gel

Minutes

Days

Hours

CONTACT TIME

Effect of contact-time

0

2

4

6

8

10

12

14

16

WR 100 WR 80 Cream WR 90 Gel

CEM I - w/c 0.70 (methode instandard)

• Concrete quality– High w/c-ratio give “low” quality concrete with high amount

of capillary pores

» Acceptable penetration depth also for products with

• Low active content

• Short contact time

– Low w/c-ratio give “high” quality concrete with low amount of capillary pores

» Acceptable penetration depth only for products with

• high active content

• medium to long contact time

Planiseal WR-line – substrate dependent parameters

Effect of w/c ratio

0

1

2

3

4

5

6

WR 100 WR 80 Cream WR 90 Gel

CEM II- w/c 0.45 (28-daysold waterstored)

CEM II - w/c 0.70 (28-days old waterstored)

0

1

2

3

4

5

WR 100 WR 80Cream

WR 90 Gel

CEM II - w/c 0.45(14-days oldwaterstored)

CEM II - w/c 0.70(14-days oldwaterstored)

0

1

2

3

4

5

6

WR 100 WR 80Cream

WR 90 Gel

CEM II- w/c 0.45(7-days oldwaterstored)

CEM II- w/c 0.70(7-days oldwaterstored)

Effect of cement-type

0

1

2

3

4

5

6

7

8

9

WR 100 WR 80 Cream WR 90 Gel

CEM II- w/c 0.45 (28-daysold waterstored)

CEM I - w/c 0.45 (28-daysold waterstored)

0

0,5

1

1,5

2

2,5

3

WR 100 WR 80Cream

WR 90 Gel

CEM II - w/c 0.45(14-days oldwaterstored)

CEM I - w/c 0.45(14-days oldwaterstored)

0

0,5

1

1,5

2

2,5

WR 100 WR 80 Cream WR 90 Gel

CEM II- w/c 0.45 (7-days old waterstored)

CEM I- w/c 0.45 (7-days old waterstored)

• Time of application– The migration are dependent of the capillary pores in the concrete, and that

water in these has evaporated.

– In general best results after 28 day

Planiseal WR-line – substrate dependent parameters

0

1

2

3

4

5

6

7

8

9

CEM I- w/c 0.45 (7-days old

waterstored)

CEM I - w/c 0.45(14-days oldwaterstored)

CEM I - w/c 0.45(28-days oldwaterstored)

WR 100

WR 80 Cream

WR 90 Gel

Planiseal WR-line documentation

PLANISEAL WR-LINE

Principle 1 (PI): Protection against Ingress - 1.1 hydrophobic impregnation (H)

Principle 2 (MC): Moisture Control- 2.1 hydrophobic impregnation (H)

Principle 8 (IR): Increasing Resistivity by Limiting moisture content: - 8.1 hydrophobic impregnation (H)

Planiseal WR line –EN 1504-2

Demands WR 100 WR 80 Cream

WR 90 Gel

EN 1504-2 yes yes Yes

Loss of mass after freeze-thaw-salt stress*

The loss of mass of the surfaceof the impregnated specimenmust occur at least 20 cycleslater than that of the notimpregnated specimen.

C= 46 C > 20 C = 48

Depth of penetration

class I: < 10 mmclass II: ≥ 10 mm

Class I (5mm) Class II (11mm) Class II (13,3 mm)

Water absorption and resistance to alkali

Absorption ratio <7,5 %, comparedwith the untreated specimenAbsorption ratio (afterimmersionin alkali solution) <10 %.

4.3%

5.9%

5.1%

5.3%

1.7 %

7.8 %

Drying rate coefficient

class I: > 30 %class II: > 10 %

Class I (54.5%) Class I (38.6%) Class I (88%)

Diffusion of chlorideions**

63 % 68 % 90 %

*This test is only necessary for structures which may come in contact with de-icing salts**subject to national standards and national regulations

Planiseal WR line –EN 1504-2

Demands WR 100 WR 80 Cream

WR 90 Gel

EN 1504-2 yes yes Yes

Loss of mass after freeze-thaw-salt stress*

The loss of mass of the surfaceof the impregnated specimenmust occur at least 20 cycleslater than that of the notimpregnated specimen.

C= 46 C > 20 C = 48

Depth of penetration

class I: < 10 mmclass II: ≥ 10 mm

Class I (5mm) Class II (11mm) Class II (13,3 mm)

Water absorption and resistance to alkali

Absorption ratio <7,5 %, comparedwith the untreated specimenAbsorption ratio (afterimmersionin alkali solution) <10 %.

4.3%

5.9%

5.1%

5.3%

1.7 %

7.8 %

Drying rate coefficient

class I: > 30 %class II: > 10 %

Class I (54.5%) Class I (38.6%) Class I (88%)

Diffusion of chlorideions**

*This test is only necessary for structures which may come in contact with de-icing salts**subject to national standards and national regulations

INCREASED FREEZE /THAW - RESISTANCE

Without hydrophobic impregnation With hydrophobic impregnation

Planiseal WR line –EN 1504-2

Demands WR 100 WR 80 Cream

WR 90 Gel

EN 1504-2 yes yes Yes

Loss of mass after freeze-thaw-salt stress*

The loss of mass of the surfaceof the impregnated specimenmust occur at least 20 cycleslater than that of the notimpregnated specimen.

C= 46 C > 20 C = 48

Depth of penetration

class I: < 10 mmclass II: ≥ 10 mm

Class I (5mm) Class II (11mm) Class II (13,3 mm)

Water absorption and resistance to alkali

Absorption ratio <7,5 %, comparedwith the untreated specimenAbsorption ratio (afterimmersionin alkali solution) <10 %.

4.3%

5.9%

5.1%

5.3%

1.7 %

7.8 %

Drying rate coefficient

class I: > 30 %class II: > 10 %

Class I (54.5%) Class I (38.6%) Class I (88%)

Diffusion of chlorideions**

*This test is only necessary for structures which may come in contact with de-icing salts**subject to national standards and national regulations

• Nordic region:

– NT Build 515

• w/c: 0,45

• 15% NaCl-solution

• Filter-test

But the most important – STOP THE CHLORIDES!!!

• Nordic region:

But the most important – STOP THE CHLORIDES!!!

0

20

40

60

80

100

Filtereffect

WR 100

WR 80Creme

WR 90 GEL

The higher value – better protection!!

Planiseal WR line –EN 1504-2

Demands WR 100 WR 80 Cream

WR 90 Gel

EN 1504-2 yes yes Yes

Loss of mass after freeze-thaw-salt stress*

The loss of mass of the surfaceof the impregnated specimenmust occur at least 20 cycleslater than that of the notimpregnated specimen.

C= 46 C > 20 C = 48

Depth of penetration

class I: < 10 mmclass II: ≥ 10 mm

Class I (5mm) Class II (11mm) Class II (13,3 mm)

Water absorption and resistance to alkali

Absorption ratio <7,5 %, comparedwith the untreated specimenAbsorption ratio (afterimmersionin alkali solution) <10 %.

4.3%

5.9%

5.1%

5.3%

1.7 %

7.8 %

Drying rate coefficient

class I: > 30 %class II: > 10 %

Class I (54.5%) Class I (38.6%) Class I (88%)

Diffusion of chlorideions**

63 % 68 % 90 %

*This test is only necessary for structures which may come in contact with de-icing salts**subject to national standards and national regulations

• Hydrofobic impregnation• Protective effect

– filter effect for Chlorides

– frost/thaw salt resistance

» depends mainly on the product

• Durability of treathment– Penetration depth

» depends on product, concrete (cement, w/c, silica) and applicaton (time, moisture content)

Concluding remarks

Thank you for your attention!