Product Data Sheet Show all documents

Sikafloor®-20 PurCem® LP

HEAVY DUTY, HIGH STRENGTH, EASY TROWEL, POLYURETHANE-HYBRID FLOORING SCREED

Sikafloor®-20 PurCem® LP is a three part, water dispersed, high strength, smooth trowel grade, coloured polyurethane modified, cement and aggregate screed suitable for floors subject to heavy loading, abrasion and chemical exposure.
It has a textured aggregate surface providing medium to heavy profile slip resistance and is typically installed at 6 to 9 mm thick.

  • Fluid consistency requires less labour to install than conventional heavy duty modified PU trowel grade screeds
  • Excellent chemical resistance. Resists a wide range of organic and inorganic acids, alkalis, amines, salts and solvents. Please refer to the Chemical Resistance Chart or consult Technical Department
  • Similar coefficient of thermal expansion to concrete, allowing movement with the substrate through normal thermal cycling. It will perform and retain its physical characteristics through a wide temperature range from -40 °C (-40 °F) up to +120 °C (248 °F)
  • Steam cleanable at 9 mm thick
  • Non tainting / odourless
  • VOC free
  • High mechanical resistance. Behaves plastically subject to impact. Will deform but will not crack or debond
  • Slip resistance, natural textured surface provides anti-slip traction
  • High abrasion resistance resulting from its silica aggregate structure
  • Rapid one step application. Normally, no concrete primer or sealer required
  • Can be applied to substrates with high moisture content (7 days old or mature damp concrete)
  • Jointless. Extra expansion joints are not necessary; simply maintain and extend existing expansion joints up through the Sikafloor® -PurCem® flooring system
  • Easily maintained
Product Data Sheet Show all documents

Usage

Sikafloor®-20 PurCem® LP is used as a final flooring wear layer in areas of heavy loading, high mechanical abrasion and impacts, aggressive chemical attack, thermal shocks and high temperature stresses, such as in :
  • Food processing plants (wet or dry process areas, freezers and coolers, thermal shock areas)
  • Chemical plants
  • Laboratories
  • Workshops

Advantages

  • Fluid consistency requires less labour to install than conventional heavy duty modified PU trowel grade screeds
  • Excellent chemical resistance. Resists a wide range of organic and inorganic acids, alkalis, amines, salts and solvents. Please refer to the Chemical Resistance Chart or consult Technical Department
  • Similar coefficient of thermal expansion to concrete, allowing movement with the substrate through normal thermal cycling. It will perform and retain its physical characteristics through a wide temperature range from -40 °C (-40 °F) up to +120 °C (248 °F)
  • Steam cleanable at 9 mm thick
  • Non tainting / odourless
  • VOC free
  • High mechanical resistance. Behaves plastically subject to impact. Will deform but will not crack or debond
  • Slip resistance, natural textured surface provides anti-slip traction
  • High abrasion resistance resulting from its silica aggregate structure
  • Rapid one step application. Normally, no concrete primer or sealer required
  • Can be applied to substrates with high moisture content (7 days old or mature damp concrete)
  • Jointless. Extra expansion joints are not necessary; simply maintain and extend existing expansion joints up through the Sikafloor® -PurCem® flooring system
  • Easily maintained

Packaging

Part A : 3 kg plastic drum
Part B : 3 kg plastic jerrycan
Part C : 25 kg plastic lined, double paper bags

Part A+B+C: 31.0 kg ready to mix units

Colour

Part A : Liquid / coloured
Part B : Liquid / brown
Part C : Powder / natural grey

Available colours (all are approximate): Cream, Green, Grey, Light Grey.

Product Details

Product Information

Chemical base

Part A : Water borne polyol
Part B : Isocyanate
Part C : Aggregates, cement and active fillers

Shelf life

Parts A and B :

12 months from date of production. Must be protected from frost.

Part C :6 months from date of production. Must be protected from humidity.

Storage conditions

If stored properly in original, unopened and undamaged sealed packaging, in dry conditions at temperatures between +18 °C and +30 °C.

Density

Part A :~1.07 kg/L
Part B :~1.24 kg/L
Part C :~1.58 kg/L
Part A+B+C mixed :~2.08 ± 0.03 kg/L
Technical Information

Shore D Hardness

~80 - 85

Compressive Strength

28 days

~45 N/mm2

28 days~50 N/mm2

Tensile Strength in Flexure

28 days~9.5 N/mm2 (3 mm)
28 days~10.0 N/mm2

Tensile Strength

28 days~4.3 N/mm2

Tensile Adhesion Strength

~1.75 N/mm2(failure in concrete)

(1.5 N/mm2 is the minimum pull off strength of the recommended concrete substrate)

Reaction to Fire

Class B(fl) S1

Permeability to Water Vapour

To Water Vapour :

(6.1 mm)

0.148 g/h/m2

Thermal Resistance

The product is designed to withstand thermal shock caused by steam cleaning when thickness is 9 mm.

Skid / Slip Resistance

Substrate

SRV Dry

SRV Wet

Sikafloor®-20 PurCem® LP

70

65

TRRL Pendulum, Rapra 4S Slider

 

Application

Application Information

Mixing ratio

Part A : B : C = 1 : 1 : 8.3 (packaging size = 3 : 3 : 25) by weight

Ambient Air Temperature

10 °C min. / +30 °C max.

Layer Thickness

6 mm min. / 9 mm max.

Relative Air Humidity

80 % max.

Dew Point

Beware of condensation!
The substrate and uncured floor must be at least 3 °C above dew point to reduce the risk of condensation or blooming on the floor finish.

Substrate Temperature

10 °C min. / +30 °C max.

Substrate Moisture Content

The substrate can be dry or damp (saturated surface dry or SSD) with higher moisture content (No ponding water). Check rising moisture.

The substrate needs to be visibly dry and have adequate pull-off strength minimal 1.5 N/mm2.

Pot Life

Temperature

Time

+10 °C~35 - 40 min
+20 °C~22 - 25 min
+30 °C~15 - 18 min
+35 °C~12 - 15 min

Curing time

Temperature

Foot Traffic

Light Traffic

Full Cure

+10 °C

~24 h

~48 h

~7 d

+20 °C

~24 h

~24 h

~5 d

+30 °C

~12 h

~18 h

~3-4 d

+35 °C~12 h~18 h~3-4 d

Notes: Times are approximate and will be affected be changing ambient and substrate conditions, particularly temperature and relative humidity.
If used other primers than Scratch Coat refer the Technical Data Sheet of the respective product. Make sure that the primer and the scratch coat layer is fully cured before application of Sikafloor® PurCem® previous layer.

 
Consumption

Consumption

LayerProductConsumption
Scratch CoatSikafloor®-21 PurCem® LP~1.5 kg/m2
Body CoatSikafloor®-20 PurCem® LP~2.0 kg/m2/mm

This figure is theoretical and does not allow for any additional material due to surface porosity, surface profile, variations in level or wastage etc.
Application steps

MIXING

Material and ambient temperature will affect the mixing process.
If necessary, condition the materials for best use to 18 °C – 27 °C.
Premix part A and B separately, make sure all pigment is uniformly distributed with a low speed electric stirrer.
Start mixer and add parts A and then B and blend for 30 seconds.
Gradually add part C (aggregate) to the mixed resin parts over a period of 15 seconds. DON’T DUMP!
Allow part C to blend for further 2 minutes minimum, to ensure complete mixing and a uniform moist mix is obtained. During the operations, scrape down the sides and bottom of the container with a flat or straight edge trowel at least once (parts A+B+C) to ensure complete mixing. Mix full units only.
When adding aggregate to prepare a patching mortar, gradually add the 9 kg of 2 – 3 mm dry quartz sand after mixing the full set.
Use a low speed electric stirrer (300-400 rpm) for mixing parts A and B.
For preparation of the mortar mix use a pan type revolving mixer.

APPLICATION

Prior to application, confirm substrate moisture content, r.h. and dew point.
Proceed with placement of the material to facilitate the release of entrapped air from the mix and CO 2 from the reaction. Do so in every batch mixed in a consistent manner in order to avoid colour differences due to increased temperatures in the reaction Pour the mixed Sikafloor®-20 PurCem® LP onto the substrate and spread evenly with a rake or screed box to the required thickness. Take care to spread newly mixed materials across the transition of previously applied mixes (wet edge), before the surface begins to set.
Finish the surface using a flat, round edge steel trowel.
A short pile roller can be used once or twice, and always in the same direction, to provide a more homogeneous finish to the surface. No excessive backrolling!
Excessive backrolling or trowelling will bring up more resin to the surface, reducing the desired anti-lip surface texture which characterises this product.
As a second texture option, selected mineral aggregates can be broadcast on the wet surface and sealed with a top coat of 1 x Sikafloor®-31 PurCem® LP to lock in the aggregate. In this last case, allow a minimum of 36 hours cure period at 20 °C before light traffic.


Flow check

Top internal dia.

70 mm

Bottom internal dia.

100 mm

Height

60 mm
Flow210 ± 10 mm

 

CLEANING OF TOOLS

Clean all tools and application equipment with Thinner C immediately after use.
Hardened / cured material can only be mechanically removed.

CLEANING

To maintain the appearance of the floor after application, Sikafloor® -20 PurCem® must have all spillages removed immediately and must be regularly cleaned using rotary brushes, mechanical scrubbers, scrubber dryers, high pressure washers, wash and vacuum techniques, etc., using suitable detergents and waxes.

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