Sikadur 31+ Rapid is a 2-part, fast-curing, epoxy-based structural adhesive. It is moisture-tolerant, bonds to many construction materials and can also be used for structural concrete repairs, joint filling, and crack sealing.

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• Features & Benefits
• Uses
• Substrate Preparation
• Mixing
• Application
• Limitations

Features & Benefits

   
• Easy to mix and apply
• Very low VOC (GEV Emicode EC1 PLUS)
• Very good adhesion to many construction materials
• Hardens without shrinkage
• Can be applied up to 30 mm thick in one layer
• Can be applied at temperatures between +5 °C and +20 °C

Uses

The Product is used as an adhesive for:

• Structural concrete repair (Principle 3, Method 3.1 of EN 1504-9). Repair of spalling and damaged concrete in buildings, bridges, infrastructure and superstructure works
• Structural strengthening (Principle 4, Method 4.3 of EN 1504-9). Bonding plate reinforcement
• Structural strengthening (Principle 4, Method 4.4 of EN 1504-9). Adding mortar

The Product is used for bonding the following materials:

• Concrete
• Natural stones
• Ceramics
• Fibre cement
• Mortar
• Brick masonry
• Brick slips
• Steel
• Iron
• Wood 

The Product if used for repairing and reprofiling:

• Structural concrete elements such as beams, columns, and walls
• Non-structural concrete elements
• Small patches and edges

The Product is used for filling and sealing:

• Joint arrises
• Crack arrises
• Non-structural static cracks
• Holes
• Voids

Substrate Preparation

Substrate Quality

Concrete, Masonry, Mortar, Stone:

• Concrete and mortar must be at least 28 days old
• Substrates must be sound, clean, dry or matt damp with no standing water
• Substrates must also be free from contamination such as ice, dirt, oil, grease, coatings, laitance, efflorescence, surface treatments and loose friable material

Steel:

• Surfaces must be sound, clean, dry and free of all contaminants such as dirt, oil, grease, coatings and loose friable material

Wood:

• Surfaces must be sound, clean, dry and free of all contaminants such as dirt, oil, grease, coatings and loose friable material

Substrate Preparation

IMPORTANT - Reduced adhesion performance Surface contamination such as dust and loose material, including that caused during substrate preparation can reduce performance.

Thoroughly clean all substrate surfaces before application of the product by vacuum or dust removal equipment.

Concrete, Masonry, Mortar, Stone:

Suitable techniques for substrate preparation include the following:

• Abrasive blast cleaning
• Needle gunning
• Light scabbling
• Bush hammering
• Grinding
• Prepare the substrate mechanically using a suitable technique

The substrate has an open textured gripping surface profile.

Steel:

Suitable techniques for substrate preparation include the following:

• Abrasive blast cleaning
• Rotating wire brush
• Grinding
• Prepare the substrate mechanically using a suitable technique

The substrate has a bright metal finish with a surface profile to satisfy the necessary tensile adhesion strength requirement.

Wood:

• Prepare the substrate by planing, sanding or using other suitable equipment

Mixing

IMPORTANT

Maintaining workability and handling time

• When using multiple units during application, do not mix the following unit until the previous one has been used

Pre-Batched Units

• Mix full units only. Note: Mix only the quantity which can be used within its pot life
• Prior to mixing all parts, mix part A (resin) briefly using a mixing spindle attached to a slow speed electric mixer (maximum 300 rpm)
• Add part A to part B (hardener) and mix parts A+B continuously for at least 3 minutes until a uniformly coloured smooth consistency mix has been achieved
• IMPORTANT: Do not overmix. To ensure thorough mixing, pour materials into a clean container and mix again for approximately 1 minute. Mixing time for A+B = 4 minutes

Application

IMPORTANT -Provide temporary support for heavy components positioned vertically or overhead

Bonding

Preconditions - Prior to application, confirm dew point conditions before and during application.

• IMPORTANT: On damp prepared concrete substrates, always apply by brush and work the Product well into the substrate. Apply mixed adhesive to the prepared surfaces with a spatula, trowel, notched trowel or by gloved hand
• For optimum adhesion, apply adhesive to both surfaces that require bonding
• For heavy components positioned vertically or overhead, provide temporary support until the Product has fully hardened. Hardening will be dependent on ambient temperatures

Repair

Preconditions - Prior to application, confirm dew point conditions before and during application.

• Place temporary formwork as required
• IMPORTANT: On damp prepared concrete substrates, always apply by brush and work the Product well into the substrate. Apply mixed adhesive to the prepared surfaces with a spatula, trowel or by gloved hand

Note: For repairs greater than 30 mm deep, the Product must be applied in layers.

• Scratch the surface of the freshly applied intermediate layer to form a key for the subsequent layer
• Apply successive layers once the previous layer has hardened
• If the time between layers is going to be more than 2 days, blind the wet adhesive to excess with quartz sand immediately after application

Joint Filling and Crack Sealing

• Apply mixed adhesive to the prepared surfaces with a spatula or trowel

Cleaning Of Tools

• Clean all tools and application equipment with Sika Thinner C immediately after use
• Hardened material can only be removed mechanically

Limitations

• Sikadur resins are formulated to have low creep under permanent loading. However, due to the creep behaviour of all polymer materials under load, the long term structural design load must account for creep
• Generally, the long term structural design load must be lower than 20−25 % of the failure load. A structural engineer must be consulted for load calculations for the specific application