Product Data Sheet Show all documents

Sikafloor®-21 PurCem®

Medium to heavy duty self-smoothing polyurethane screed

Sikafloor®-21 PurCem® is a multi-component, water-based coloured polyurethane hybrid screed with self-smoothing properties. It has a smooth, matt, impervious, hard wearing surface and is typically installed at 3 - 6 mm thickness.

  • Good chemical resistance.
  • High mechanical resistance.
  • High glass transition point.
  • Non-tainting / odourless.
  • VOC free and environmental friendly.
  • Can be applied to substrates with high moisture content (7 days old, or mature damp, concrete).
Product Data Sheet Show all documents

Usage

Sikafloor®-21 PurCem® is used as a scratch coat primer, basecoat and wear coat layer in Sikafloor®PurCem® system build ups, in areas of medium to heavy loading, high chemical exposure and abrasion.

Advantages

  • Good chemical resistance.
  • High mechanical resistance.
  • High glass transition point.
  • Non-tainting / odourless.
  • VOC free and environmental friendly.
  • Can be applied to substrates with high moisture content (7 days old, or mature damp, concrete).

Packaging

Part A (pre-tinted)

3.00 kg plastic pail

Part A (neutral)2.50 kg plastic pail

Part B

3.00 kg plastic jerry can

Part C

15.00 kg plastic lined, double paper bags

Part D0.500 kg plastic pouch for substrate A neutral

Part A (pre-tinted)+B+C: 21.0 kg ready to mix units

Part A (neutral)+B+C+D: 21.0 kg ready to mix units

Colour

Part A (pre-tinted)

Coloured liquid

Part A (neutral)Light beige liquid

Part B

Brown liquid

Part C

Natural grey powder

Part DColourpack as per list below for part A neutral

Standard colours: Agate Grey, Beige, Dusty Grey, Yellow Green, Golden Yellow, Carmine Red, Pebble Grey, Ultramarine Blue.

Product Details

Sustainability / Certifications / Approvals

ENVIRONMENTAL INFORMATION

  • Conformity with LEED v4 MRc 2 (Option 1): Building Product Disclosure and Optimization – Environmental Product Declarations.
  • Conformity with LEED v4 MRc 4 (Option 2): Building Product Disclosure and Optimization - Material Ingredients.
  • Conformity with LEED v2009 IEQc 4.2: Low-Emitting Materials - Paints and Coatings.
  • Complies AgBB for use in in indoor environment. Test.
 

APPROVALS / STANDARDS

  • Polyurethane screed for concrete protection according to the requirements of EN 1504-2:2004 and conforms to the requirements of EN 13813: 2002, DoP 02 08 02 02 001 0 000002 1088, certified by Factory Production Control Body, 0086, certificate 541325, and provided with the CE-mark.
  • EN1186, EN 13130, and prCEN/TS 14234 standards, and the Decree on Consumer Goods, representing the conversion of directives 89/109/EEC, 90/128/EEC and 2002/72/EC for contact with food stuffs, according to test report by ISEGA, 32758 U11 and 32759 U11, both dated December 6th, 2011. (Tests performed on Sikafloor® -20/21/22/29 and 31 PurCem® in standard and LP versions).
  • British Standards Specifications (BSS) acceptance for use in the UK.
  • Campden and Chorleywood Food Research Association, Ref. S/REP/125424/1a and 2a, dated 8th February, 2012.
  • Fire classification report according to EN 13501-1 from Exova Warrington Fire for Sikafloor®-21 PurCem® No.317047, dated 24th of March, 2012.
  • Liquid water transmission rate test report from the Technology Centre, Ref. 15456 dated January 25th, 2012.
  • Abrasion resistance tests performed by Face Consultants Ltd., according to BS 8204-2:2003, report ref. FC/12/3850, dated January 17th, 2012. (Tests performed on Sikafloor® -20/21 PurCem®).
  • Impact resistance values tested at PRA, Ref. nº 75221-151, dated January 11th, 2012.
  • Slip resistance properties according to DIN 51130 tested at MPI (Materialprüfung und Entwicklung), test reports refs. Nº 12-6639-S/12 and 12-6641-S/12, dated August 7th, 2012.
  • Thermal expansion coefficient and freeze-thaw cycle resistance performed at RWTH / IBAC, report nº M-1614 dated May 29th, 2012.
Product Information

Chemical Base

Water-based polyurethane cement hybrid

Shelf Life

Part A

12 months from date of production. Protect from freezing.

Part B

12 months from date of production. Protect from freezing.

Part C

6 months from date of production. Must be protected from humidity.

Part D24 months from date of production. Protect from freezing.

Storage Conditions

Original, unopened and undamaged sealed packaging, in dry conditions at temperature between +5 °C to +30 °C.

Density

Part A (pre-tinted)+B+C mixed: ~1.93 kg/l ± 0.03 (at +20°C)

Part A (neutral)+B+C+D mixed: ~1.93 kg/l ± 0.03 (at +20°C)
Technical Information

Compressive Strength

> 50 N/mm2 after 28 days at +23°C / 50% r.h.

(BS EN 13892-2)

Flexural Strength

> 10 N/mm2 after 28 days at +23°C / 50% r.h.

(BS EN 13892-2)

Tensile adhesion strength

Concrete failure

(EN 1542)

Application

Application Information

Mixing Ratio

  • Part A (pre-tinted) : B : C = 1 : 1 : 5 (packaging size = 3.0 : 3.0 : 15) by weight
  • Part A (neutral) : B : C : D = 0.87 : 1 : 5 : 0.13 (packaging size = 2.615 : 3.0 : 34 : 0.385) by weight

Mix full units only.

Layer Thickness

Scratch coat 1 - 2 mm
Base and wear coats 3 - 6 mm

Ambient Air Temperature

+10°C min. / +40°C max.

Relative Air Humidity

85% 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 other disturbance of the surface on the floor finish.

Substrate Temperature

+10°C min. / +40°C max.

Substrate Moisture Content

Can be installed on substrates with higher moisture content. No ponding water. Check rising moisture. The substrate needs to be visibly dry and have adequate pull-off strength min 1.5 N/mm2.

Pot Life

Temperatures

Time

+10°C

~35 - 40 minutes

+20°C

~22 - 25 minutes

+30°C~15 - 18 minutes
+35°C~12 - 15 minutes

Waiting Time / Overcoating

Before overcoating Sikafloor® -21 PurCem® allow:

Substrate Temperature

Minimum

Maximum

+10°C

24 hours

72 hours

+20°C

24 hours

48 hours

+30°C12 hours24 hours
+35°C12 hours24 hours

Times are approximate and will be affected be changing ambient and substrate conditions, particularly temperature and relative humidity.

If primers other than ascratch coat are used, refer to 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

~1.93 kg/m2/mm
Application steps

MIXING

Premix part A with a low speed electric stirrer and then add part B and mix for 30 seconds. For the colourpack version, premix part A neutral with a low speed electric stirrer and add part D to it. Mix until a uniform colour is achieved. Ad part B and mix for 30 seconds.

Use a double paddle (axis) mixer and gradually add part C (aggregate) to the mixed resin. 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.

Mixing Tools
Use a low speed electric stirrer (300 - 400 rpm) for mixing parts A and B. For preparation of the mortar mix use a double paddle mixer.

APPLICATION

Prior to application, confirm substrate moisture content, relative humidity and dew point. As a scratch coat Sikafloor®-21 PurCem® can be applied using a steel trowel. As a body coat Sikafloor®-21 PurCem® can be applied using a toothed trowel or pin screed, to the desired thickness, or a steel trowel. Remove air with a spike roller.
For further details please refer to the related system data sheet.

CLEANING OF TOOLS

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

 

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