Sika® WT-220 PMY
Sika® WT-220 PMY is a combined water resisting and crystalline waterproofing admixture used to reduce permeability of concrete.
- Reduced water penetration under pressure
- Reduced water absorption
- Enhancement of self-healing properties of the concrete
- Improvement in resistance against chemical attack
- Reduced vapour transmission
Usage
Sika® WT-220 PMY has been specifically formulated to produce high quality watertight concrete for the following:- Tunnels
- Basements
- Culverts
- Canals
- Water-tanks
- Inspection-chambers
- Manholes
- Swimming pools
Advantages
Sika® WT-220 PMY consists of a mixture of cements, amino alcohols and some other active ingredients. These active materials will form non-soluble materials throughout the pore and capillary structure of the concrete and seal the concrete permanently against penetration of water and other liquids. In addition, the special formula and ingredients enhances the self-healing properties of concrete and will improve the ability to heal concrete cracks- Reduced water penetration under pressure
- Reduced water absorption
- Enhancement of self-healing properties of the concrete
- Improvement in resistance against chemical attack
- Reduced vapour transmission
Packaging
3.5 kg plastic bags
Colour
Grey powder
Product Details
Shelf Life
6 months from the date of production
Storage Conditions
Store properly in original, unopened and undamaged sealed packaging in dry and covered conditions.
Density
~750 kg/m³
Compatibility
Sika Joint systems is highly recommended to seal construction, movement and difficult joints.
Construction Joints | Movement Joints | Special/Difficult Joints |
Sika® Waterbars | Sika® Waterbars | Sika® Fuko |
SikaSwell® | Sikadur® Combiflex® | Sikadur® Combiflex® |
Sika® Hydrotite | Sikaflex® | |
Sika® Fuko | ||
Sikaflex® |
Concrete produced using the Sika® WT-220 PMY will produce concrete with improved water impermeability. 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.
Concreting Guidance
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, a curing compound such as Antisol® E or 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.
Specific Advice
Quality Assurance
- A record of the batched concrete constituents shall be kept by the supplier of the product and forwarded to the Supervising Officer as requested.
Quality Control
- As quality control, cube strength tests shall be performed at 7 and 28 days. At random intervals, additional 150 mm cubes can be casted in order to perform water penetration test as per DIN 1048, part 5.
- The frequency of both tests shall be determined according to site requirements or as per the proposed sampling plan below:
- For every 1 000 m³ of concrete batched, 6 cubes shall be tested for compressive strength at 7 and 28 days
- For every 2 000 m³, 3 additional cubes shall be made for water penetration test at 28 days as per DIN 1048, part 5
Requirements
- The dispensing, dosing and mixing of the various admixtures for the said concrete shall adhere strictly to the final mix design (after trial mix) and in accordance with batching sequence clearly defined in the Sika® WT-220 PMY product data sheet
- The placing, placing height and compaction of the said concrete shall be in accordance with BS 8110
- The curing protection of the said concrete during hardening stage shall be in accordance with BS 8110
- The spacing of reinforcements shall be sufficient for aggregates to pass and avoid segregation
- The formwork shall be clear, soundly constructed and must be grout tight. All this shall be in accordance with BS 8110, including its removal
- 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 must be patched up with a polymer modified mortar or other approved materials. The material and patching shall be proposed by Sika and approved by the supervising officer
- *Recommended Slump = 100 ± 25mm
Concrete Mix Design
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 w/c-ratio 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).
Application
DISPENSING
Before batching, check the truck/mixer to ensure no water is in the drum/mixer. Batch concrete based on the concrete mix design and mix homogeneously. Add Sika® WT-220 PMY and mix for at least 5–10 minutes with the concrete mixing truck at full speed.
Alternative dispensing sequence can be used provided that the batcher can ensure a homogeneous mix. The homogeneity of the mix after dosing of Sika® WT-220 PMY remains the responsibility of the applicator. The w/c ratio and consistency control remains the responsibility of the concrete producer. Actual plant trials must be carried out before jobs commence to determine both fresh and hardened properties.
Recommended Dosage
0.8–2.0 % of Sika® WT-220 PMY by weight of total cementitious binder