Hydrophobic - · PDF fileNa2SO4.10H2O Sodium sulphate, Glauber salt 3CaO ... and many of these act as hydrophobic agents by blocking these larger pores, but still allowing

Silicate Emulsion Paint. Hydrophobic

ActivSil Technology

Abolin Co Greece Building Sustainable with Innovations

Restoration of historical centers • Water degrading effect • Restoration process • Künzel’s theory Silicate emulsion paints ‐ Properties ‐ Application


Restoration of buildings Why this increasing of the restoration in our cities? Mature societal claims

Promotion from the Government or Town

halls. Target: Conservation of historical city centers

Subsidies to the owners of the historical buildings to be restored


Restoration of façades

Connection between the building and the city (and citizens)

Requirements :

‐ Aesthetic ‐ Durability, ‐ transpirability,

waterproofing, isolation, …

Façades


Degradation Which is the major degrading agent for the building materials of the façade?

Water Water Penetration

Capillarity

Pouring Rain

Condensation by Cooling

Capillary Condensation

Hygroscopic Absorption

DIRECT action by: Erosion / solubilization Softening of materials

Expansivity in case of frost


Osmosis

Part 1

Water INDIRECT action by: Carrying with it salts: surface crystallization as white efflorescence, crusts, and degradation of the materials by crystallization inside.

Sulphates MgSO4.7H2O Magnesium sulphate, amaro salt CaSO4.2H2O Calcium sulphate, gypsum Na2SO4.10H2O Sodium sulphate, Glauber salt 3CaO.Al2O3.3CaSO4.32H2O Ettringite

Nitrates Mg(NO3)2.6H2O Magnesium nitrate Ca(NO3)2.4H2O Calcium nitrate 5Ca(NO3)2.4NH4NO3.10H2O Calcium and ammonium nitrate


Part 2



Part 3

Water INDIRECT action by: Carrying with it salts: surface crystallization as white efflorescence, crusts, and degradation of the materials by crystallization inside.

Chlorides CaCl2.6H2O Calcium chloride NaCl Sodium chloride Carbonates Na2CO3.10 H2O Sodium carbonate K2CO3 Potassium carbonate CaCO3 Calcium carbonate, calcite Ca(HCO3)2 Calcium bicarbonate


Water


INDIRECT action by: Favouring sprouting and development of vegetation, bacteria, microorganisms, Mildews, fungi, lichens and insects.

Part 4

Reasons: Existence of nutrients

in the wall Water Organic polymer

of the coatings pH close to 7



Part 5

Insulating power of the wall

Presence of WATER


Decreases the insulating power of the wall (1/Λ Thermic insulation coefficient)

20% moisture in a cement plaster

HALVES the insulating power of the plaster

Künzel Theory


w (water absorption coefficient) < 0,5 kg/m2h0,5

Sd (resistance to vapour diffusion) < 2 m

Or w∙Sd < 0,1 kg/mh0,5 w

kg/m2h0,5 Sd m

w Sd kg/mh0,5

Künzel theory < 0,5 < 2 < 0,1 Emulsion paints Emulsion plasters Pure silicate paints Silicate emulsion paints Hydrophobic ActivSil

≈ 0,25 ≈ 0,15 > 0,5 < 0,5 << 0,5

> 1 > 1,5 < 0,05 < 0,05 < 0,05

> 0,2 > 0,2 ≈ 0,02 ≈ 0,02 ≈ 0,01


ACTIVSIL Reasons to use this type of paint in buildings

Part 1

High permeability to the water vapour

Silicate emulsion paint I II III

Sd (m)

0,02

0,04

0,05

Thickness of coating (mm)

0,17

0,17

0,17

The water vapour diffusion current density indicates how many grams of water vapour can diffuse per square meter area in one day through a paint layer. This can be calculated from the Sd value


Reasons to use this type of paint in buildings

Part 2

Long life (petrification / silicification) = Chemical reactions

A.‐ With the material of the wall

I. K2O × nSiO2 + Ca(OH) CaO × SiO2 + (n-1)SiO2 + 2KOH + CO2 K2CO3

II. K2O × nSiO2 + mSiO2 K2O × (m+n)SiO2

Reaction with sand (rough surfaces)

Reaction with lime (calcium hydroxide):

B.‐ With the CO2 of the atmosphere

Total Silicification (Result: insoluble silica gel)

III. K2O × nSiO2 + CO2 nSiO2 + K2CO3

RESULT: Insoluble solid of inorganic/mineral nature composed of: SiO2, inorganic pigments, insoluble silicates of Ca, Al,..

ACTIVSIL



Part 3

ACTIVSIL

Low water absorption

Capillarity refers to the absorption/ desorption of water as liquid. Capillarity is a function of pore structure. It can be altered by coatings and additives and many of these act as hydrophobic agents by blocking these larger pores, but still allowing the smaller pores to remain open. In this way the pore structure may be kept open for hygroscopic and vapour permeable transfer of moisture but closed to capillary transfer of moisture. Capillarity is measured by placing a standard cube of material in water, with all sides sealed except the bottom. The weight of the material is then measured from time to time and this is expressed as a Co ‐ efficient w kg/m2h0.5

Hydrophobic Action !



Part 4

ACTIVSIL

High UV resistance Colorants obtained from special metallic oxides resistant to UV radiation.

Real Binder (silica) is high resistant to UV



Part 5

ACTIVSIL

Biocide effect against development of algae, mildews, lichens,…

Water solution K2O. x SiO2 x > 3,3 Molar ratio Not classified as dangerous material Not classified as irritant, if other ingredients do not cause this effect

High pH (12) With this pH value is not possible the development of this type of microorganisms



Part 6

ACTIVSIL

Maintenance of the aspect

Low tendency to the dirt pickup Particles of dust are not trapped by the paint Autowashability (hidrophilic). Slow chalking effect. Rain removes some microns of the surface

Chalking Scale

• Two Component Silicate

• Emulsion Silicate

Months



Part 7

ACTIVSIL

Naturally’ looking matt surface appearance / Maintenance of the morphology of the surface

Penetration in the wall up to 7-8 mm

NEVER gloss



Part 7a

ACTIVSIL

Energy Savings Performance

The creation of surfaces of high reflectivity and emissivity in the urban environment constitutes an easily applicable and economic passive cooling method that contributes in the reduction of urban temperatures. The creation of such surfaces can be achieved with the use of “cool” materials which are characterized from :

‐ High solar reflectance ‐ High infrared emittance incident

sunlight I

reflected sunlight Rsol I

net emitted thermal radiation E σ (T4 - Tsky

4)

opaque surface at temperature T

convection

conduction


Reasons to use this type of paint in buildings ACTIVSIL

Energy Savings Performance – Application onto Exterior Walls

Optical Properties – Solar Reflectance, Infrared Emittance

a/a Coating Code Color SR

SR_NIR (700‐

2500nm)

Infrared emittance

(error 0.02)

1 ActivSil White WHITE 0.90 0.93 0.89

2 ActivSil CB 013

LIGHT BLUE 0.82 0.87 0.90

3 ActivSil CB 015 LIGHT RED 0.78 0.89 0.89

4 ActivSil CB 016

LIGHT GREEN 0.81 0.87 0.89

5 ActivSil CB 022

LIGHT GREY 0.76 0.84 0.90

6 ActivSil CB 019

LIGHT OCHRE 0.85 0.91 0.88

Part 7b

The use of ACTIVSIL on Buildings envelope drive to cooling needs reduction.

Less energy used, less CO2 emissions, lower electricity bills



Part 7c

• Cooling load reduction ‐ Less heat penetrates into building

• Energy Savings ‐ Minimize the need for cooling • Money savings • Improved thermal comfort conditions • Improved public health conditions • Enhanced building’s durability ‐ Less thermal

stress • Improved microclimatic conditions ‐

Urban Heat Island Mitigation

Energy Savings Performance – Application onto Exterior Walls Benefits from the use



Part 8

Air Purification and Smog Reduction

ACTIVSIL can be formulated to perform photocatalytic action against: Nitrogen Dioxide Ozon Benzene Formaledeheyde Toluene Bacteria

The inorganic nature of ACTIVSIL can

ensure an excellent photocatalytic effect with excellent life expectancy


Application rules of the silicate emulsion paints ACTIVSIL

Appropriate substrate: Mineral/ inorganic substrates

Primer of silicate ‐ Impregnating agent ‐ Paint thinner ‐ Transparent

Silicate emulsion paint

‐ Finished coat ‐ White / pigmented

Dual system:

Part 1



Part 2a

Preparation of the substrate

Surfaces should be cleaned, dried, grease‐free • New plasters: Shall be allowed to weather for 4‐6 weeks to dry off completely.

• Plasters with efflorescences or chalking : Shall be brushed to remove the dust of

the surface.

• Old existing paints: Weakly compact coatings should be removed. Highly compact, with good adhesion, should be cleaned if they present efflorescence or crusts.



Part 2b

Preparation of the substrate

Substrate repairs • The restoration plaster to repair the damaged surfaces should have the same texture and resistance than the original plaster. • The repaired areas should be dry before application of the silicate emulsion paint. In case of dark colours and in order to avoid different tonalities, the restoration plaster should be treated with fluates. • Small cracks, flakes and surface damages are repaired with a silicate putty which Can be instantly prepared by mixing with sand the silicate emulsion paint.


Part 2c


Impregnation

Target = Achieve a uniform absorption = Uniform Colour • Use a silicate primer • or use a mixture of: primer, water and finished paint in proportions 1:1:1. Silicate primer is used in any mineral surface except gypsum Gypsum: Use Cool Barrier Grip Nano primer coat or a primer based in a styrene‐acrylic emulsion in water with a content in organic polymer of less than 5%.

CaSO4 + H2O + nSiO2.K2O nSiO2.CaO + K2SO4


Part 2d


Primer Target = Substrate reinforcement

Primer is also used for : Reinforce poor compact substrates Avoid a high absorption of paint in some type of concrete Wait between application of the primer and the top coat (at 20ºC, 65% of relative humidity) Minimum 12 hours

ACTIVSIL Part 2e


Application of the top coat

Roller of short hair, brush, air‐less (50º, 150‐180 bar)

• Apply to filled or weathered substrate for at least 4 weeks. • Protect adjacent and not to be painted surfaces with proper masking. • Apply by roller, brush, or air‐less • Two coats of the same product (primer, mid‐coat, top‐coat)

have to be applied wet on wet. • After application of each product, wait at least 24 hours before

applying the next one. • Do not apply in the sun or to warm wall from previous insolation. • Do not apply with strong wind. • Do not apply below 8ºC or in case of frost at night. • Do not apply to wet wall. Drain moisture. • Wear protective glasses.

Application rules of the silicate emulsion paints


Application of the top coat

Roller of short hair, brush, air‐less (50º, 150‐180 bar)


Part 2f

The application should be made wet on wet to avoid different tonalities (A worker put the paint on the wall and other worker extend it with the roller) Connections should be carried out in edge of windows, friezes, eaves,… Re‐paintings should be done with a round brush with long hair and in perpendicular direction to the wall. Extent perfectly the paint (avoid thick coats)


Most frequent defects ACTIVSIL

Defect Cause Non uniform, irregular shade

Surface spots

Crusts and efflorescences

Adhesion problems Surface dusting Bloomy areas Stripes

Interrupted work. Marks of resumed work.

Uneven primer or poor pre‐treatment Ca(OH)2 or sats driven to the surface by wall moisture Unsuitable substrate. Suitable substrate treated with hydrophobic agents. Presence of release agents. Low temperature during application. Insufficient pretreatment.

Substrate moisture. Excessive ambient moisture. Warm substrate. Application in the sun or with warm wind.


RESTORATION PROCEDURE ACTIVSIL

1 Inspection of damages & assessment of their extent - Humidity spots - Salts efflorescenses - plaster flakings and decays - mildews, algae, 2 Search of the damage origin - Non waterproof foundations - Inefficient drainage - Leaking roof - Rain penetration, condensation. 3 Cause removal - Foundation waterproofing - Setting up of a horizontal barrier 4 Restoration - Removal of damaged coating or plaster - Remaking of hydrophobe plaster and transpiring silicate paint 5 Other works

1. Insulation of foundations 2. Drain 3. Horizontal Barrier 4. Treating wall salts (no plaster) 5. Grouting and sealing of cracks… 6. Revoke restoration 7. Painting breathable silicate


WHERE TO APPLY ACTIVSIL

New Building Painting Works

Museums and Historical Buildings Restoration and Energy Conservation

Public Buildings or Infrastructures dealing with Inorganic paints applica ons (Organic content ˂ 5%)

Superior Durability and Aesthetic Appearance

ActivSil Technology

ABOLIN CO GREECE. 22‐24 GALAXIA STR, ATHENS GREECE Tel: 0030 210 5575568, Email: [email protected], Web: www.abolinco.com

Documents

Hydrophobic - · PDF fileNa2SO4.10H2O Sodium sulphate, Glauber salt 3CaO ... and many of these act as hydrophobic agents by blocking these larger pores, but still allowing