Sikadur®-32 Fix

Sikadur®-32 Fix is a two-component, solvent-free, epoxy-based structural adhesive reinforced with polysulfides, specially developed to achieve a high-performance bond between hardened concrete and fresh concrete. It is used in concrete joints, extensions, repairs, and projects where the new concrete must be firmly bonded to the existing substrate.

It should not be confused with a conventional primer. Sikadur®-32 Fix is classified as a structural adhesive in accordance with UNE-EN 1504-4 and may be used in reinforcement work in accordance with Principle 4, Method 4.4 of UNE-EN 1504-9, intended to increase load-bearing capacity by bonding fresh concrete to hardened concrete.

It also functions as a bonding layer for epoxy resin mortars on smooth concrete or mortar substrates.

In addition to concrete and cementitious mortars, Sika specifies high adhesion to substrates such as:

stone;

brick;

fiber-cement;

steel and other metals;

glass;

and certain synthetic materials.

The formulation cures without shrinkage, is impervious to liquids and water vapor, and can be applied to damp surfaces provided there is no standing water.

This tolerance to moisture is particularly useful in concrete repairs where it is difficult to achieve a completely dry substrate.

Compressive strength

approximately 57.7 MPa.

Modulus of elasticity in compression

approximately 2.1 GPa.

Tensile strength

approximately 3.4 MPa, with cohesive failure of the concrete.

Shear strength (hardened/hardened concrete)

approximately 13.8 MPa.

Shear strength of hardened concrete against fresh concrete: approximately 13.6 MPa.

Glass transition temperature

approximately 66.7 °C.

These data explain why it is used as a structural bond and not simply as an assembly adhesive.

The condition of the surface is critical. The concrete must be sound, strong, and free of:

dust;

oils and greases;

surface laitance;

loose or poorly bonded parts;

paint residues and other products;

contaminants from other work.

Sika recommends preparing the substrate primarily using mechanical methods, such as chipping, shot blasting, milling, sandblasting, or steel-bristle brushes, until a sound and sufficiently rough surface is achieved.

Dust must then be carefully removed, for example using clean, water- and oil-free compressed air.

The product is supplied in pre-measured batches.

Component A

58 parts.

Component B

42 parts.

Mix both components for at least 3 minutes using a low-speed electric mixer, at a maximum of approximately 300 rpm, until a completely uniform consistency and color are achieved.

Sika then recommends transferring the mixture to a clean container and remixing for approximately 1 minute. This procedure helps prevent poorly mixed areas on the walls or bottom of the container and reduces the unnecessary incorporation of air.

Only prepare the amount that can be used within the mixture’s pot life.

a brush;

a roller;

a rubber trowel;

or another suitable method depending on the surface.

It is important to thoroughly saturate the substrate, especially when working on damp concrete.

Once Sikadur®-32 Fix has been applied, the fresh concrete must be placed within the adhesion window specified by Sika. At 20 °C, the working time for the mixture is approximately 45 minutes, while the specified timeframe for pouring the new concrete is up to 6 hours, depending on actual job site conditions.

Ambient temperature

+10 to +35 °C.

Substrate temperature

+10 to +30 °C.

The substrate may be damp, but not waterlogged.

Approximate full cure time

7 days.

Temperature directly affects the viscosity and working time of the mixture: at high temperatures, the available working time decreases.

1. 01 300–0.500 kg/m².

The actual amount depends primarily on the roughness, porosity, and temperature of the substrate. A highly irregular concrete surface will require more product to be properly saturated than a uniform substrate.

When working on vertical or steeply sloped surfaces and increased sag resistance is required, Sika recommends adding up to approximately 3% by weight of Aerosil 200.

This modification must be carried out in accordance with the manufacturer’s technical documentation and only when application conditions require it.

Fresh material must be immediately removed from tools using Sika® Colma Cleaner. Once the epoxy resin has cured, it can only be removed by mechanical means.

1 kg pre-measured batch.

4 kg pre-measured batch.