Concrete structures, whether in residential, commercial, or industrial settings, are prone to wear and tear over time. Cracks, spalling, and other forms of damage can compromise the integrity and aesthetics of concrete surfaces. Fortunately, with the right materials and techniques, these issues can be effectively addressed. One such solution is the use of dura.rep FR, a fibre-reinforced repair mortar. In this article, we will explore the step-by-step process of repairing concrete using dura.rep FR, ensuring a durable and long-lasting result.
Why choose dura.rep FR for concrete repair?
dura.rep FR is a high-performance, fibre-reinforced repair mortar designed for vertical and overhead concrete surfaces. It offers several advantages, including:
• High compressive strength (22-25 N/mm²)
• Resistance to carbon dioxide and chlorides
• Suitable for repairs in layers of 10-80 mm vertically and 10-50 mm overhead
• Excellent adhesion to the substrate
Bombela Gautrain Project concrete repair and protection
Step-by-step guide to concrete repair using dura.rep FR
1. Surface preparation
Before applying dura.rep FR, it is crucial to prepare the substrate properly. The surface should be thoroughly wetted with clean water to satisfy absorption. Any standing or excess water must be removed. For priming, use dura.bond GP acrylic emulsion, working it firmly into the damp substrate with a short-bristle brush. This ensures a film intimate with the contact area for immediate repair.
2. Priming the concrete
For concrete surfaces subject to permanent immersion, prime with epidermix 345 ‘Slow-set’. This primer should be worked firmly into the damp substrate with a short-bristle brush. If the primer dries before applying the mortar, re-prime the area.
3. Mixing the repair mortar
Ensure that the areas for reinstatement are prepared and ready to receive the repair mortar. Only use complete bags of dura.rep FR, as part bag mixes are not permitted. Follow the product instructions for mixing, using potable quality water. Add the dura.rep FR to the mixing water, ensuring not to exceed the maximum volume of water stated for each bag.
4. Application of the repair mortar
Apply the mixed dura.rep FR by gloved hand or trowel to the prepared and primed surface. Pay particular attention to packing behind and between the reinforcement and ensuring thorough compaction. The mortar can be applied in one operation by building up to the required profile in wet-on-wet layers. For thicker sections, build up in wet-on-dry layers, ensuring each layer is scratch keyed, cured, and re-primed before applying subsequent layers.
5. Curing the repair mortar
Curing techniques should be instigated immediately following the application of the repair mortar. Large areas should be cured as trowelling progresses. dura.bond GP can be low-pressure spray applied as a curing membrane. In fast-drying conditions, supplement this with a polyethylene sheet taped around its edges.
6. Surface coating for immersed conditions
For surfaces exposed to immersed conditions, apply duraflex®, a two-component polymer-modified cementitious coating. Ensure the total dry film thickness is not less than 1.8 mm, providing protection against chloride ingress and CO? diffusion resistance.
Conclusion
Repairing concrete using dura.rep FR is a practical and effective method to restore the integrity and appearance of damaged concrete surfaces. By following the proper preparation, priming, mixing, application, and curing techniques, you can achieve a durable and long-lasting repair. For more information on dura.rep FR and other concrete repair solutions, visit a.b.e. Construction Chemicals.
