Sika MonoTop 615HB

MonoTop 615HB Product Features

Sika MonoTop®-615 HB is a high build, one component, cementitious, polymer modified repair and re-profiling mortar containing silica fume and crystalline free silica aggregate. Meeting Class R4 of EN 1504-3 (the highest structural repair class), it contains Ferrogard corrosion inhibitor providing additional reinforcement protection. Single layer application thickness up to 70 mm makes it ideal for thick layer repair of extensively damaged concrete.

• Class R4 structural repair mortar to EN 1504-3 (highest class)
• Up to 70 mm thick per single layer
• Polymer modified for increased durability
• Contains Ferrogard corrosion inhibitor for reinforcement protection
• Superior workability and finishing
• Suitable for hand and machine application
• 28-day compressive strength approx. 46 MPa
• Very low shrinkage behaviour
• Low permeability

Applications

• Thick layer repair of spalling and damaged concrete in buildings, bridges, infrastructure, and superstructure works
• Structural restoration work (EN 1504-9 Principle 3, methods 3.1 and 3.3)
• Structural strengthening — increasing bearing capacity by adding mortar cover (EN 1504-9 Principle 4, method 4.4)
• Preserving or restoring passivity — increasing cover to replace contaminated or carbonated concrete (EN 1504-9 Principle 7, methods 7.1 and 7.2)

Why Choose MonoTop 615HB

• R4 Highest Class — Meets EN 1504-3 R4, the highest structural repair class for the most demanding applications
• 70 mm Single Layer — Far exceeds standard repair mortars (typically 30 mm), significantly reducing the number of application passes
• Ferrogard Corrosion Protection — Built-in corrosion inhibitor provides long-term additional protection for reinforcement in repaired areas
• Low Permeability — Effectively resists moisture and harmful substance ingress, extending repair service life
• High Strength — 28-day compressive strength approx. 46 MPa, with approx. 18 MPa achieved at 24 hours

Packaging

Technical Specifications

System Structure

MonoTop 615HB vs MonoTop 612 Comparison

Application Method

1. Substrate Preparation — Concrete must be thoroughly cleaned, free from dust, loose material, and surface contamination. Steel reinforcement must be prepared by abrasive blasting or high-pressure water to Sa 2 (ISO 8501-1), with surface profile greater than 2 mm. Refer to EN 1504-10. Concrete substrate must be at least 28 days old
2. Bonding Primer — Apply Sika MonoTop-610 as bonding slurry on the pre-wet substrate. Any bonding primer shall be applied on a pre-wet substrate and the repair mortar applied wet-on-wet. For reinforcement corrosion protection, apply coating wet on dry reinforcement, then apply repair mortar while coating is still wet
3. Mixing — Add 3.5–4.0 litres of clean water per 25 kg of powder. Pour water into container first, gradually add powder while stirring, and mix with a low speed drill (< 500 rpm) for at least 3 minutes until uniform consistency
4. Application — Thoroughly pre-wet the substrate (recommended 2 hours prior). Keep the surface wet with a dark matt appearance — no glistening or standing water. Build up layers from bottom to top by pressing mortar into the repair area. Finish with a float or rough-cast tool once the mortar has started to stiffen
5. Curing — Protect fresh mortar from damp, condensation and water for at least 12 hours. When using polythene sheets, ensure all edges are fastened and no air movement occurs over the mortar surface

Important Notes

• Protect freshly applied mortar from damp, condensation, and water for at least 12 hours
• For spray application, water jet blasting is the preferred surface preparation method with surface profile greater than 2 mm
• Sika MonoTop-610 should be used as bonding slurry for both hand and spray applications
• When curing with polythene sheets, ensure all edges are sealed to prevent air circulation over the fresh mortar
• Once the product has started to set, it should be discarded — do not add more water to improve workability
• Concrete substrate must be a minimum of 28 days old
• Do not exceed the recommended water dosage
• Clean all tools with water immediately after use; hardened material must be removed mechanically

FAQ

What is the difference between MonoTop 615HB and MonoTop 612?

MonoTop 615HB is an R4 class (highest class) high build repair mortar with a maximum single layer thickness of 70 mm, 28-day strength of approx. 46 MPa, and contains Ferrogard corrosion inhibitor. MonoTop 612 is R3 class, maximum 30 mm per layer, 28-day strength approx. 40 MPa, without corrosion inhibitor. Choose 615HB when thick layer repair or additional reinforcement protection is required.

Does MonoTop 615HB require a bonding primer?

Yes. Sika MonoTop-610 should be used as a bonding slurry for both hand and spray applications. This differs from MonoTop 612, which generally does not require a primer for manual application. For reinforcement corrosion protection in demanding applications, SikaTop Armatec 110 EpoCem can be used.

How to calculate MonoTop 615HB consumption?

Consumption is approximately 19 kg per m² per cm of thickness. For example, a 5 cm thick repair requires approximately 95 kg/m². Each 25 kg of powder mixed with 3.5–4.0 litres of water yields approximately 15 litres of mortar. Packaging is 20 kg per bag. Actual consumption varies with substrate roughness and application thickness.

What does the Ferrogard corrosion inhibitor do?

Ferrogard is Sika's proprietary corrosion inhibitor that migrates to the reinforcement surface after the repair mortar is applied, forming a protective film that reduces the rate of steel corrosion. For concrete repair projects where reinforcement corrosion has occurred, using MonoTop 615HB with Ferrogard provides additional long-term corrosion protection for the reinforcement.