Sika® WT-220 PMY

6 months from the date of production

Store properly in original, unopened and undamaged sealed packaging in dry and covered conditions. Protect from direct sunlight, moisture, water and rain.

~750 kg/m³

Sika Joint systems is highly recommended to seal construction, movement and difficult joints.

Concrete incorporating Sika® WT-220 PMY will reduce water permeability in concrete. However, the system is not designed as a moisture vapour barrier and should therefore only be specified under the following conditions:

• No finishing is required
• A breathable finish such as plaster, quarry tiles, floor hardener, etc. is required

If non-breathable finishes such as epoxy, polyurethane flooring systems, vinyl tiles, carpet, etc. are to be applied, a temporary moisture barrier will be required as an underlay. Please contact our Technical Service Department for more information.

Concrete produced with the Sika® WT-220 PMY requires good concreting practices for placing and finishing. For basement car parks, dry shake floor hardeners such as Sikafloor®-3 QuartzTop can be used without restriction.

Curing
As curing affects watertightness of the concrete, care should be taken to ensure proper curing. When concrete has hardened and finishing completed, curing compound such as Sika® Antisol® E or Sika® Antisol®-90 shall be applied at the recommended rate (refer to the respective product data sheets).

Alternatively, traditional curing methods (for example polythene sheets, water spray, ponding or wet hessian) can be used.

Quality Assurance

• The batch record of the concrete constituents shall be kept by the concrete supplier and forwarded to the Supervising Officer as requested.

Quality Control

• As part of quality control, compressive strength tests shall be carried-out at 7 and 28 days. At random intervals, additional 150 mm cubes shall be made for water penetration test according to BS EN 12390-8 : 2009.
• The frequency of both tests shall be determined according to site requirements or as per the proposed sampling plan below:

• The proportioning, dispensing, dosing and mixing of the various materials in the concrete shall strictly follow the final mix design (decided after plant trials).
• The placing, placing height and compaction of the concrete shall be in accordance with BS 8110
• The curing/protection of the concrete during hardening stage shall be in accordance with BS 8110
• The spacing of reinforcements shall be sufficient for aggregates to pass through and avoid segregation
• The formwork shall be clean, rigidly constructed and must be grout tight.
• All construction, expansions, crack-induced joints, abutment of old and new buildings, openings such as pipe penetrations and projections, etc., shall be treated with Sika’s Joint Sealing materials or approved equivalent, to details approved by the Supervising Officer.
• All tie-rods holes must be patched up with a polymer modified mortar or other approved materials. Use Sika® MonoTop® patch repair mortar.
• Workability. The concrete slump shall be > 100 mm. No segregation and bleeding.

Laboratory trials are always recommended to evaluate and confirm actual water reduction and consistence class.

Basic waterproof concrete
Concrete mix design depends on local requirements and/or local standards for watertight concrete systems.

Sika® waterproof concrete
Sika® WT-220 PMY has been formulated for use in concrete with minimum cement content of 350 kg/m³ and a maximum water-cement ratio (w/c) of 0.45. Depending on the specific mix design, the dosage of HRWR/superplasticiser has to be evaluated in order to achieve a S3/F4 consistence class (EN206-1).

Before mixing, check the truck/mixer to ensure no water is in the drum/mixer. Weigh the materials (based on approved concrete mix design) and mix the concrete until homogeneous. Add Sika® WT-220 PMY into the drum/mixer and mix for another 5–10 minutes at full speed.

Alternative dispensing sequence can also be used. However, the homogeneity of the mix after dosing of Sika® WT-220 PMY remains the responsibility of the applicator. The maximum water-cement ratio (w/c) and consistency requirements must be adhered to at all times and remains the responsibility of the concrete supplier. Plant trials must be carried out before commencement of actual supply, to determine both fresh and hardened properties of the concrete after the addition of Sika® WT-220 PMY.

Minimum 1 × 3.5 kg bag of Sika® WT-220 PMY per m³