Sika concrete bonding adhesive is the best way to bond new concrete with old. Are you wondering how to use this adhesive? We've asked experts who provided a guide to help you with your Sika application.
Concrete bonding adhesives come in two forms where one requires mixing and comes in tubs. The other comes in small ready-to-use cartridges that are for sticking and sealing. For best results, follow the product instructions accordingly.
If you find this interesting, keep scrolling as we discuss in elaborate detail the use of concrete bonding adhesives, necessary preparations, and other types of adhesives.
How To Apply Concrete Bonding Adhesive
You can use the Sika concrete bonding adhesive in tubs as either a bonding agent or an admixture. The small cartridges are straightforward to use since you only need to load them into a caulking gun and apply them.
Using Sika concrete bonding adhesive lessens the water requirement in the mix or completely replaces it. The proportion of water and Sika as an admixture in a concrete and repair mortar mix may vary.
Applying Sika concrete bonding adhesive depends on how you intend to use it. If you plan to use it as a bonding agent, then here is how you should mix it:
- Add one part cement to two parts aggregate (sand). Add enough amounts of Sika to achieve a paint-like viscosity.
- Prepare the area for bonding by using a wire brush to spread the mixture on all exposed surfaces and corners.
- Immediately add the concrete before the Sika dries.
You can also use Sika as an admixture to concrete, mortar, or grout. Here is how to do that:
- Add Sika to the concrete or repair mortar by replacing the amount of water in the mix. You can use it to lower the water-cement ratio or eliminate water from the mixture.
- If the mixture requires one liter of water and 10% Sika, you must eliminate the 10% from one liter of water and replace in Sika with an equivalent volume. To meet the one-liter water-aggregate requirement, the mixture should have 900mL water and 100mL Sika concrete bonding adhesive.
- Mix until you reach the desired consistency.
For bonding and sealing construction materials like insulation boards, glass, and even metal, you can use the Sika adhesive that comes in cartridges. You will need a caulking gun for the application. Just load the cartridge, point at the site, and apply.
Sikaflex is an adhesive that works great on indoor and outdoor applications. The product boasts self-leveling, waterproof, and fast-curing qualities.
How To Ensure Successful Bonding
The product alone is not enough to bond concrete and other construction material surfaces. You will have to observe specific requirements to bond the materials successfully.
Strong Substrate Surface
When bonding objects, especially weighty ones, the anchor substrate must be able to bear the weight. Concrete and steel are strong substrates are ideal for heavy objects. Painted or tiled surfaces have poor adhesion and, therefore, should be avoided.
Before applying the adhesive, you must clean the substrate surface. Equal parts of isopropyl alcohol and water should be enough to dissolve grease and wash off the dust. But this is just one part of the preparation.
A stripped surface works fine in removing surface contaminants as well. To increase adhesion by 40%, abrade the substrate surface finely in a circular motion using sandpaper, scrub pads, or fine steel wool.
You can also use a palm sander when covering a larger surface area. Remember to keep the abrasions fine to avoid compromising the bond strength. For the adhesive to work wonderfully, you must ensure that the substrate surface is primed and sealed.
Priming coated or painted surfaces will aid the adhesion process. Sealing porous surfaces will maximize the contact surface, allowing better adhesion. The sealant to be used will depend on the material of the substrate, whether it is concrete, metal, or glass.
Correct Product Usage
Of course, not all products are created equal. Some are for rough outdoor surfaces, and others adhere better to smooth indoor surfaces. Before prepping the surface, go over the product instructions carefully.
Correct Application Procedure
Sika products are classified into water-borne, solvent-borne, and reactive adhesives. For water-borne adhesives, the substance hardens once the water has evaporated. Its application needs to be thin and uniform throughout the surface. It also requires one substrate to be porous to aid in water loss.
On the other hand, solvent-borne adhesives do not necessarily require a porous substrate. The hardening of this adhesive type will require exposing the substance openly for a short period after initially joining it. It aids solvent loss to allow the adhesive to eventually bond upon rejoining.
Reactive adhesives need moisture from the environment to cure. Applying these adhesives in vertical strips or dots of about one to three-millimeter thicknesses is recommended for better anchorage.
Assistive Fix While Curing
While the adhesive is still curing, you can adjust the objects on the surface. You may employ a temporary mechanism to keep things in place until the curing process is complete. Although, this may not be necessary when using some of the latest adhesives in the market.
What Are The Different Types Of Bonding Adhesives
Bonding adhesives come in different forms and are best suited for specific uses.
Acrylic fortifier has a resin-based formulation and is mainly used as bonding adhesive admixtures. Its application is usually for thin Portland cement coatings in outdoor settings. Given its water-resistant nature, this concrete adhesive works well in swimming pools.
It also helps reduce cracking due to shrinkage and keeps the base and finish coats from separating. The requirements before application are the same. The substrate's surface must remain clean from dirt, dust, and grease.
You should remove any paint from the surface to ensure adhesion. Also, remember that acrylic fortifiers cannot be combined with concrete bonding adhesives. Mixing with polymer-modified cement products or air-entraining agents is not advised.
Styrene-Butadiene Rubber (SBR) Latex is made from synthetic polymers. In construction, it is an adhesive used as an admixture for mortars, cement bond coats, and concrete. Its water-resistant feature makes it a sturdy material against aggressive chemicals and freeze/thaw cycles.
The synthetic polymer's flexible nature helps improve bond and tensile strength. This makes it a suitable admixture for topping and repairing concrete surfaces and building horizontal structures like bridges and parking decks. Please note that this is a toxic substance to aquatic life.
So, even if it is water resistant, it is not an ideal material for structures that will house marine animals. Constructors should ensure that they dispose of SBR Latex at the appropriate facility as state laws and regulations require. When working with this material, you should also observe the use of protective gear such as gloves and goggles.
Polyvinyl Acetate or PVA is another polymer-based bonding agent commonly known as glue. Unlike SBR Latex, PVA is water-based and non-toxic. Its general intended use for construction is as an additive to concrete and plasters.
PVA works exceptionally well with cement and concrete and bonds to most substrates. When bonding, apply the PVA on the surface with fewer pores and place it on the other substrate before it dries.
If used as a primer (usually before plastering) and cement admixture, the dilution ratio is one part PVA to three parts water and five parts water if used as a sealer.
Polymer-Enriched Thin-Set Mortar
Thin-set mortar combines cement and other aggregates work best for tile and stone projects. Some thin-set mortars are modified by adding latex and other polymers to increase the bonding strength.
This type of bonding agent has a variety of uses. As adhesive, you can use this with carpet installations, wall and flooring installations, and exterior finishes. It can work as a mortar for concrete repair, sports flooring, and coatings.
Since several brands use acrylic fortifiers, SBR Latex, PVAs, and thin-set mortars, it is essential to note that the mixture and dilution ratio may vary. Read and follow the product instructions for use and storage.
As can be gleaned, acrylic fortifiers and polyvinyl acetate cannot be combined traditionally. But Sika concrete bonding adhesive is a combination of both. It is a revolutionary and versatile product, perfect for indoor and outdoor use.
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