VINNAPAS 529 ED Emulsão VAE para impermeabilização cimentícia

How Does VINNAPAS 529 ED Modify Cementitious Waterproofing Slurries?

The VINNAPAS 529 ED VAE emulsion – a poly(vinyl alcohol)-stabilised, vinyl acetate–ethylene copolymer dispersion – functions as the primary polymer binder in two‑component, flexible cementitious waterproofing membranes. Upon blending with a powder component containing Portland cement CEM I 42.5 R, graded silica sands, and supplementary cementitious materials, the aqueous dispersion is uniformly distributed throughout the slurry. As cement hydration initiates, the polymer particles coalesce concurrent with crystal growth, forming a continuous film that interpenetrates the cementitious matrix. This composite structure is characterised by a co‑continuous morphology in which the VAE film bridges micro‑cracks and reduces interconnected capillary porosity, leading to water absorption values below 0.05 kg·m⁻²·h⁻⁰.⁵ when tested according to EN 1062‑3:2008. The low glass‑transition temperature of approximately –15 °C and minimum film‑forming temperature around 0 °C enable film coalescence at ambient site temperatures without external plasticisers, preserving long‑term resistance to saponification and oxidative degradation. Typical addition rates, expressed as dry polymer on cement weight (p/c), fall within 0.15 to 0.25, a window where crack‑bridging ability, measured under EN 1062‑7:2004 at –10 °C, can exceed 1.2 mm without rupture, while maintaining pull‑off adhesion to concrete substrates above 1.0 MPa (EN 1542:1999).

The emulsion is supplied as a milky‑white liquid with the following typical physical characteristics; all values reflect lot‑release data obtained at 23 °C and 50 % relative humidity.

Property	Typical Value	Test Method
Solids content	55 ± 1 %	Infrared drying, 140 °C /15 min
Brookfield RVT viscosity, spindle 3/20 rpm	500 – 1500 mPa·s	ISO 2555:2018
pH	4.5 – 5.5	ISO 976:2013
Density at 20 °C	approx. 1.06 g·cm⁻³	ISO 2811‑2:2011
Glass‑transition temperature, Tg (midpoint, DSC)	approx. –15 °C	ISO 11357‑2:2020
Minimum film‑forming temperature, MFFT	approx. 0 °C	ISO 2115:1996
Average particle size	approx. 1 µm	Laser diffraction, ISO 13320:2020

Field records from continuous twin‑shaft compulsory mixers (L/D ratio 4:1, tip speed 1.5 m·s⁻¹) indicate that pre‑wetting the mixing vessel with a portion of the gauging liquid prior to adding the powder component eliminates early‑stage binder agglomeration that is otherwise observed when the emulsion is charged second. Batch‑to‑batch viscosity drift of the emulsion component, although limited to ±10 % of the nominal mid‑range value, can manifest as a perceptible change in slump flow of the wet slurry. Operators on waterproofing contracting sites standardise the slump flow to 150 ± 10 mm (Haegermann cone, modified for cementitious slurries) by fine‑tuning the total water demand, a step that becomes critical when ambient temperatures exceed 30 °C. At such temperatures, pot‑life decreases to approximately 45–60 minutes, and the surface must be shut down with a light water mist if the open time prior to final trowelling extends beyond 20 minutes. The freshly applied membrane requires protection against rain and direct sunlight for at least 24 hours; otherwise, surface laitance enriched in un‑coalesced polymer leads to a chalking interface that reduces inter‑coat adhesion for multilayer build‑ups.

When Crack Bridging at –10 °C Is Required, VAE Emulsion Composition Dictates Performance

The ethylene content of the copolymer, tightly controlled during semi‑batch emulsion polymerisation, governs the degree of soft‑segment flexibility that remains effective at sub‑zero temperatures. VINNAPAS 529 ED achieves a dynamic mechanical storage modulus (E′) below 10 MPa at –10 °C, as measured by DMA at 1 Hz on free films conditioned at 50 % RH. This stiffness envelope, combined with a polymer‑cement ratio of at least 0.20, enables the cured composite to bridge static cracks opening up to 1.5 mm at –10 °C (EN 1062‑7, procedure A). Formulators must observe that raising the p/c ratio beyond 0.30, while enhancing flexibility, depresses compressive strength below 15 MPa and simultaneously increases water vapour transmission beyond acceptable limits for buried‑side waterproofing. Conversely, selection of a harder VAE grade with Tg near 0 °C—commonly employed in tile adhesives—reduces crack‑bridging at low temperature to below 0.4 mm, insufficient for decks subject to freeze‑thaw cycling. Published data for this specific configuration demonstrates that a dry film thickness of 2.0 mm, applied in two layers with intermediate curing of 4–6 hours, satisfies the criteria of class CM 02 per EN 14891:2017 for liquid‑applied waterproofing products used beneath ceramic tiling, including resistance to water pressure through cracks up to 0.5 mm under dynamic loading. In contrast, incorporating styrene‑acrylic emulsions—often valued for superior alkali resistance in saponification‑prone environments—introduces a trade‑off: their higher modulus at low temperatures necessitates heavier plasticiser loads, which migrate over time and embrittle the membrane. Extensive cyclic weathering data on external basement waterproofing (20 cycles of –15 °C to +70 °C under infrared radiation per EN 1062‑11:2002) show that VINNAPAS 529 ED retains over 85 % of its initial elongation at break, while a commercial styrene‑acrylic dispersion with equivalent film‑forming aid dropped below 60 %. SBR latexes, although yielding high dry adhesion, exhibit pronounced re‑emulsification when the cured membrane is in prolonged contact with standing water, as evidenced by a peel adhesion loss greater than 50 % after 7‑day immersion at 23 °C, according to tests modelled on ASTM D903 (modified for rigid substrates). Thus, for permanent water‑exposure service conditions—such as water‑retaining structures and sewage treatment plant linings—the VAE emulsion’s balanced hydrophobic‑hydrophilic domain structure affords both low water uptake and sufficient bonding to moist concrete without delamination.

Accelerated Weathering and Carbonation Resistance Data

The intermolecular hydrogen bonding between acetate groups and the hydrated cement phases, notably C–S–H, has been monitored by FTIR‑ATR on polished cross‑sections exposed in a carbonation chamber (4 % CO₂, 60 % RH, 20 °C). After 90 days, the carbonyl peak at 1740 cm⁻¹ remained unshifted, indicating negligible hydrolysis under accelerated ageing. This behaviour contrasts with acetate copolymers lacking ethylene, where a reduction in peak intensity of 12–15 % after similar exposure signals de‑esterification. The data align with pH buffering measurements inside the polymer‑rich phase: a pH drop from an initial 12.5 to 11.8 over 28 days hydration is sufficient to preserve the PVOH stabiliser layer against dissolution, an observation confirmed by nanoscratch tests where the adhesion work of the polymer–cement interface dropped less than 5 % post‑ageing versus 20–30 % for non‑VAE polymer‑modified mortars in the same study. Application on damp substrates—inevitable in below‑grade construction—does not require a primer if the substrate moisture content stays below 4 % (mass). Beyond this threshold, the osmotic pressure gradient can draw polymer‑rich water to the interface, creating a slip layer that reduces tensile adhesion below 0.5 MPa. Bond‑coat surfacing with a low‑cement slurry (p/c 0.10–0.12) has been systematically proven to restore values to ≥ 1.0 MPa even on substrates with 6 % moisture, provided the bond coat is applied within 10 minutes of the main membrane. Sites processing large volumes report using continuous mixing pumps (mortar screw pumps with stator‑rotor geometry, speed 120–150 rpm) to maintain consistent application thickness; actual film thickness variability was recorded at ±0.2 mm across 100 m² areas, a tolerance that satisfies the EN 14891 minimum dry film thickness requirement of 2.0 mm after two coats. Adding powdered defoamers based on mineral oil or polyether siloxane at 0.2–0.5 wt% of the powder component significantly reduces entrapped air, which manifests as bubbles exceeding 0.5 mm diameter in the wet film and as pinhole defects after curing. The defoamer must be introduced during dry blending before gauging; post‑addition to the wet slurry rarely achieves a bubble‑free film because the surfactant‑rich interface of the VAE emulsion resists further foam collapse. Similarly, retarding admixtures based on sodium gluconate can extend open time but, at dosages above 0.1 wt% of cement weight, interfere with film coalescence at early age, producing a soft, cheesy surface that cannot be overcoated for at least 36 hours. Avoid combination with amine‑based accelerators (e.g., triethanolamine at 0.02 %) because the alkaline pH rise to 13.5+ destabilises the PVOH colloid, inducing micro‑flocculation visible as a graininess that reduces film tensile strength by up to 30 %.

Performance differences between VINNAPAS 529 ED and common alternatives in cementitious waterproofing, tested at p/c 0.20, cured 28 days at 23 °C /50 % RH.

Property	VINNAPAS 529 ED (VAE)	Styrene‑acrylic emulsion (Tg ~ +5 °C)	SBR latex (Tg ~ –10 °C)	Test standard
Water absorption, 24 h	2.5 – 3.5 %	4.0 – 5.5 %	6.0 – 9.0 %	EN 1062‑3:2008
Crack bridging at –10 °C	1.2 – 1.5 mm	0.3 – 0.4 mm	0.7 – 1.0 mm	EN 1062‑7:2004
Adhesion to moist concrete	1.1 – 1.4 MPa	0.8 – 1.0 MPa	1.2 – 1.5 MPa (dry), 0.4 – 0.6 MPa after water immersion 7 d	EN 1542:1999
Saponification resistance (pH 12.5, 50 °C, 14 d)	no significant mass loss	no significant mass loss	partial re‑emulsification, mass loss 3–5 %	internal method, gravimetric
Film elongation at –10 °C	> 200 %	<50 %	approx. 120 %	ISO 527‑3:2018 (film thickness 0.5 mm)

Post‑cure cleaning of application equipment follows the standard protocol for PVOH‑stabilised dispersions: immediate flush with cold water before polymer film dries on metal surfaces. Hot water above 40 °C accelerates gel formation and must be avoided. The emulsion itself must be stored between +5 °C and +30 °C and is sensitive to freezing; even a single freezing‑thawing cycle irreversibly increases particle size and leads to grit formation, rendering the product unsuitable for thin‑film waterproofing.

What Limits Substrate Porosity When the Emulsion Is Applied Directly to Lightweight Concrete?

The high‑water absorption of aerated or lightweight aggregate concrete (capillary water uptake often> 0.5 kg·m⁻²·h⁻⁰.⁵) can rapidly extract gauging water from the applied slurry, depriving the VAE particles of sufficient medium for film formation. The resulting under‑coalesced layer exhibits micro‑crazing and adhesion values below 0.3 MPa. This outcome is a well‑documented processing conflict on production lines where moisture‑conditioning the substrate to a surface‑saturated dry state is logistically difficult. The use of a bonding primer—formulated from the same emulsion diluted to 20 % solids and blended with fine quartz filler (d₅₀ <100 µm)—uniformly seals the substrate within 30 minutes, allowing the main waterproofing slurry to be applied with no loss of design adhesion. Field technicians have correlated the required primer volume to substrate air‑permeability measured via the Torrent method (SIA 262/1); substrates with kT above 1.0 × 10⁻¹⁶ m² invariably demand a primer layer, while denser concretes (kT below 0.05 × 10⁻¹⁶ m²) perform acceptably without one. Direct comparison with VINNAPAS 5044 N—a redispersible VAE powder widely used in dry‑mix mortars—illuminates the role of the liquid dispersion’s lower processing viscosity. Where 5044 N requires the formulator to pre‑disperse powder into the dry blend and rely on in‑situ remixing, VINNAPAS 529 ED eliminates the hydration lag associated with powder dissolution, delivering full polymer contribution from the moment of mixing. This property is critical in fast‑track waterproofing systems where wet‑on‑wet layering is conducted within 2 hours; the emulsion‑based system develops sufficient green tack to hold vertical films without sag, whereas formulated powder‑modified mortars often require intermediate drying to prevent slumping. The trade‑off is the liquid component’s limited shelf life ( 12 months under recommended storage) and the need for freeze‑protected logistics, considerations absent with powdered products.