Concrete is an economical and versatile building material, but over time it may develop cracks from factors like shrinkage, settlement, or heavy loads. Repairing these cracks is crucial to maintain structural integrity and aesthetics of the surface of a piece of concrete - here we outline step-by-step process of how to repair cracks in concrete surfaces.
1. Assessing a Crack:
Before beginning any repair process, it is vitally important to assess and understand the severity of a crack. Cracks can be divided into three categories: hairline cracks (less than 1/8 in width), medium cracks (1/8 to 1/2 inch wide) and large (wider than 1/2 in) which will determine which approach best serves them.
2. Cleaning the Crack: For optimal adhesion of repair material, it is crucial that a crack be thoroughly cleaned before proceeding with repair work. Start by removing loose debris with a wire brush or chisel before using high-pressure water jet or compressed air to eliminate dust, dirt and any remaining loose material from within the crack. Allow time for this step to complete before moving onto step 3!
3. Applying Concrete Crack Filler:
For hairline cracks, liquid concrete crack fillers can be applied using either a squeeze bottle or caulking gun. Slowly fill the crack with the filler so that it penetrates deeply into it and fills completely before smoothing out its surface using either a putty knife or trowel and leaving to set as per manufacturer instructions.
4. Employ Epoxy Injection for Medium and Large Cracks:
Epoxy injection is an efficient repair option for medium and large-sized cracks. This technique involves injecting epoxy resin under pressure into a crack, helping bond and strengthen concrete. Start by sealing off either end of the crack using epoxy paste or adhesive before injecting an injection gun full of resin from bottom to top using an injection gun until filling all areas. Allow to set according to manufacturer specifications.
5. Repair of Structural Cracks:
Concrete cracks may indicate structural issues that require professional evaluation and repair. Structural cracks tend to be wider and deeper than regular ones and may need extra reinforcement or special repair techniques, for which professional advice or services should be sought from either a structural engineer or professional contractor. In such instances, concrete repairs should always be entrusted to a professional structural contractor for safe repair work.
6. Finishing and Sealing: Once a crack has been repaired, it is crucial to finish and seal it to safeguard it against further damage. Use a trowel or putty knife to blend repair material into surrounding concrete while using a concrete sealer or waterproofing compound as necessary to block moisture penetration and increase durability.
7. Preventive Measures:
In order to reduce the likelihood of cracking concrete structures during construction and maintenance, it is vitally important to implement preventive measures during both processes. Such steps include proper reinforcement placement, managing drying shrinkage rates, avoiding excessive loads on surfaces, as well as scheduling regular inspection and maintenance checks of structures.
Repairing cracks in concrete surfaces is an essential maintenance task to ensuring their longevity and performance. By following the steps outlined above and taking preventative measures, it is possible to effectively address cracks in the surface while protecting its structural integrity.