Hello, this is Chem Karis.
We are pleased to provide detailed information on CW-70, a high-performance silicone emulsion designed to significantly enhance the durability of construction structures.
1. What is CW-70?
CW-70 is an industrial-grade silicone emulsion based on advanced silane and siloxane technology. It is specifically engineered as an admixture for mortar and cement, providing deep-seated protection while also serving as an effective surface water repellent.
2. Key Performance & Advantages
✓ Excellent Breathability
It blocks liquid moisture while allowing air and vapor to pass through by not clogging the pores of the cement hydrates.
✓ Superior Hydrophobicity
It provides powerful water repellency and condensation prevention without interfering with the concrete's hydration reaction.
✓ Eco-Friendly Formulation:
CW-70 is a non-toxic, environmentally friendly water-based product with zero Volatile Organic Compounds (VOCs).
✓ High Compatibility
The emulsion features good dispersibility when mixed with concrete and can be combined with other additives like acrylic binders.
✓ Stability
It maintains excellent storage stability with no significant changes in viscosity or gel precipitation over time.
3. Primary Applications
✓ General Construction
Above and below ground concrete structures, swimming pools, and sewage pipes.
✓ Infrastructure
Subways, roads, tunnels, bridges (piers), dams, and airports.
✓ Product Manufacturing
Manufacturing of waterproof cement bricks, tiles, and mortar.
Chem Karis ensures global regulatory compliance, with CW-70 being listed in international inventories including TSCA (USA), IECSC (China), ECL (Korea), ENCS (Japan), and EINECS (Europe).
For technical inquiries and global partnerships, please visit our official channels:
Official Website: www.chemkaris.com
KITA Global: chemkaris.tradekorea.com
Why Concrete Needs a Water Repellent in the First Place
Concrete is porous by nature. The capillary network left behind as cement hydrates is what gives the material its permeability, and it is also the route by which nearly every common durability problem arrives. Water carried into that network brings dissolved salts with it, and the damage that follows is rarely the water itself.
Chloride and sulfate ions travelling in pore water reach the reinforcement and start corrosion, which expands and cracks the cover concrete from the inside. Water held in the pores through a freeze-thaw cycle expands and spalls the surface. Salts migrating outward and crystallising at the face produce efflorescence. In enclosed structures, persistent surface moisture supports mould growth and ruins applied finishes.
Reducing capillary water uptake addresses all of these at the same point in the chain, which is why an integral water repellent is specified so often on structures that will spend their service life in contact with water or ground moisture.
Integral Admixture or Surface Treatment?
The two approaches solve the same problem at different depths, and they are not interchangeable.
A surface treatment is applied to hardened concrete and protects the zone the liquid penetrates. It can be re-applied, but it is also the first thing lost to abrasion, weathering and surface repair, and it cannot protect a face that is later cut, drilled or chased.
An integral admixture is dosed into the mix, so the hydrophobic effect is distributed through the section rather than sitting on top of it. A cut or drilled face is still protected. CW-70 is formulated to be used either way, which is useful on projects where the same product needs to serve the precast elements and the site-applied protection.
How CW-70 Works
CW-70 is an industrial-grade silicone emulsion built on silane and siloxane chemistry. Once dispersed in the mix, it lines the capillary pore walls with a hydrophobic layer instead of filling them.
That distinction is the whole point of the product. Because the pores are lined rather than blocked, liquid water is repelled while air and water vapour still pass through — the structure stays breathable. Systems that seal the pore network instead of lining it can trap construction moisture and vapour behind the treated zone, which is a common cause of blistering under coatings and of spalling in freeze-thaw exposure.
The second requirement is that the repellent must not interfere with hydration. Anything that disturbs cement hydration costs strength development, and a durability admixture that weakens the concrete has traded one problem for a worse one. CW-70 is formulated to deliver water repellency and condensation resistance without interfering with the hydration reaction.
It is a water-based, non-toxic formulation with zero volatile organic compounds, which matters on enclosed pours — tunnels, basements, tanks — where solvent-borne products create ventilation and worker-exposure obligations. It disperses well in concrete and can be combined with other additives such as acrylic binders, and it holds its storage stability without significant viscosity change or gel precipitation.
Where It Is Used
The published application list covers three broad groups, each with a different reason for specifying a repellent:
Regulatory Inventory Listings and What They Mean for an Importer
CW-70 is listed in the major national chemical inventories: TSCA (United States), IECSC (China), ECL (Korea), ENCS (Japan) and EINECS (Europe).
For a buyer importing into any of those markets this is a practical customs and compliance question rather than a performance one. A substance that is not on the destination inventory generally cannot be placed on that market without a notification or registration step, and discovering that at the port is expensive. Inventory listings are usually the first thing a compliance team asks for, so it is worth requesting the current documentation at the quotation stage rather than after the order is placed.
What to Send Us for a Dosage Recommendation
Dosage is set against your mix, not from a catalogue figure. The more of the following you can supply, the faster we can come back with a working recommendation and a technical data sheet:
We provide free samples — you only need to cover shipping with your own FedEx or DHL account — and our sales team returns pricing within 24 hours.
Frequently Asked Questions
Q: Is CW-70 an admixture or a surface water repellent?
A: Both. It is engineered as an admixture for mortar and cement, and it also works as an effective surface water repellent.
Q: Will it stop the concrete from breathing?
A: No. It does not clog the pores of the cement hydrates, so it blocks liquid moisture while allowing air and vapour to pass through.
Q: Does it affect strength development?
A: It is formulated to provide water repellency and condensation prevention without interfering with the concrete's hydration reaction.
Q: Can it be used alongside other admixtures?
A: Yes. It has good dispersibility in concrete and can be combined with other additives, including acrylic binders. Tell us what is already in the mix and we will confirm.
Q: Does it contain solvents or VOCs?
A: No. CW-70 is a water-based, non-toxic formulation with zero volatile organic compounds.
Q: What is the dosage rate?
A: Dosage depends on your mix design and the exposure the structure will see, so it is set by trial rather than published as a single figure. Send us the mix details above and we will issue a grade-specific technical data sheet.
Related Concrete Chemistry Guides
CW-70 is one part of the CK FLOW admixture line. These guides cover the neighbouring products and the surface-side alternative:
For the full admixture range, dosage guidance and compatibility notes, see CK FLOW-SERIES Concrete Admixtures.
