Concrete repair requires a good understanding of what causes cracking and using products designed to address those issues. Most importantly, a repair must last.
Typical repair methods involve conventional placement of new concrete. This method works best on wide cracks. Contact Top Coat Technicians for professional help.
Another alternative is concrete stitching. This involves drilling entry and exit holes across the crack and securing them with metallic staples.
Cracks in concrete are a common problem that can occur due to many different factors. They range in size and severity, from hairline cracks that are barely noticeable to wide cracks that can compromise the structural integrity of a concrete slab. The severity and cause of a crack will determine the best repair methods.
Structural cracks that develop from faulty design, construction or overloading of concrete structures are the most serious and require immediate attention to ensure safety and durability. Non-structural cracks, on the other hand, are usually caused by internally induced stress in building materials and do not pose a significant risk to the structural integrity of the structure.
When a concrete slab is initially constructed, cracks will often form in the surface and surrounding areas as it hardens. These cracks are not necessarily a sign of a failure in the construction process, but may indicate that there is a problem with the sub-grade or the underlying soil. Typically, non-structural cracks can be repaired by applying an appropriate joint sealant to prevent water penetration and other damaging environmental contaminants.
The most effective method of repairing concrete cracks is by using a polyurethane resin injection. This is a high-pressure injection technique that is extremely effective in sealing wet and leaking cracks. The resin reacts with the water in the crack, chasing it away and expanding the crack to fill it up. This is a very strong and durable repair that will also help to stop any future water leaks. This type of crack repair is suitable for both dormant and active cracks.
Another option for repairing cracks in concrete is to use epoxy compounds or latex patching products. These products should be mixed according to the manufacturer’s instructions and applied to a clean crack in concrete. It is also important to clean the area around the crack to remove any dirt, mud, debris, moss or weeds that are growing in the crack.
Early thermal contraction cracks, which are caused by extreme temperature changes within a concrete structure or its immediate environment, can be repaired with a high-pressure polyurethane injection. The concrete is heated, then injected with the polyurethane resin to melt it into the concrete surface, creating a seal that will prevent future water penetration.
Deterioration
Concrete structures are subject to a wide range of environmental and in-service stresses that can lead to degradation. These stresses can be related to loading, movement, internal or external chemical attack or corrosion of reinforcement and may lead to cracking. The design of a structure must take into account these environmental stressors. During construction, the concrete must be poured properly to ensure that it is strong enough to carry loads, durable to resist weathering and long-term exposure to chemicals, and economical not only in terms of first cost but also in its ultimate service life.
The first step in a successful concrete repair should be an investigation to determine the cause of deterioration. This should include a thorough inspection of the structure, including the identification and recording of crack dispositions, patterns and intensities and their relationship to structural geometry, concreting sequence, localized detailing (especially where cracking may coincide with water leakage) and both environmental and in-service conditions.
Once the cause of deterioration has been identified, the next step is to develop an appropriate repair strategy. This should involve arresting the rate of deterioration and, where possible, protecting or reinforcing the exposed concrete. This may require the removal of existing concrete, either a full slab or just the sound section, which is then replaced using normal concrete placement techniques. It is important to note that the depth of replacement should not exceed 6 inches or the void could cause future problems.
A common mistake is to pour new concrete in the void of sunken concrete. This can cause a host of issues, from settling and spalling to premature concrete cracking. The best way to fix this is to remove the old concrete, correct the sub soil/base problem and then pour the concrete again.
Concrete repair can be very complex. It would be unrealistic to suggest that it will be possible to identify a single cause for each symptom detected during the evaluation of a structure. It is more likely that a combination of several mechanisms will be responsible. These might include corrosion of reinforcement, freeze-thaw action, carbonation, chemical alkali-silica reaction, frosting damage and sulfate attack.
Water Infiltration
Water infiltration is a common issue in concrete structures and can cause damage to the slab or foundation. It may be due to flooding, heavy rains, plumbing leaks or soil movement. This type of damage can weaken the concrete’s integrity and result in structural cracking. It is important to have this problem addressed immediately to prevent future issues such as mold, mildew, and structural damage.
Some of the signs that water infiltration has occurred in concrete include cracking and spalling. Spalling is when the surface of the concrete chips away and can be caused by a number of factors such as a high water table, hydrostatic pressure or normal shrinkage of poured concrete.
A professional contractor can assess the concrete structure and determine the appropriate repair method to prevent further damage. They will use the right tools and materials to ensure the repairs are done correctly and that they will last. Professional contractors also have the expertise to advise customers on preventative maintenance practices.
Often, hair cracks that appear in concrete walls and aren’t sealed will eventually lead to moisture infiltration. These cracks should be filled with cementitious waterproofing materials that will seal the crack and stop moisture from entering the structure. It is recommended to use a product that has good adhesion properties, can accommodate movement and be easily painted for an attractive finish.
If the cracks are larger and have formed a cavity, it may be necessary to fill these with concrete patching materials that will repair and level the concrete. This can be done by hand or with a power float depending on the size of the cavity. The cracks should then be cleaned and sanded down to prepare them for the patching material.
Although some cracks are minor and don’t affect the structure’s stability, it is still a good idea to have them repaired as soon as possible. Not only can this protect against structural damage, but it can prevent mold and mildew from growing, as well as keep soil gases such as radon out of homes and occupied spaces.
Maintenance
Keeping up with the windows, appliances, kitchen cabinets and siding on a house takes work, but don’t forget the concrete surfaces around your home. Trip hazards like out-of-level sidewalk slabs and steps are not only a nuisance, but could also lead to expensive lawsuits if someone is injured on your property.
Concrete repair requires careful inspection to determine the root cause of the problem. It’s vital to understand that cracking and deterioration are only the visible symptoms of the underlying problem. If the underlying cause of the problem is not addressed, it will continue to damage and degrade the concrete.
Maintenance is the best way to keep up with a concrete structure’s needs and extend its service life. This includes cleaning the surface, inspecting for signs of deterioration, and responding to any problems promptly.
In addition to extending the service life of the concrete, proper maintenance helps reduce environmental damage, which is an important aspect of sustainable construction. An increase in repair activities due to durability failure has a direct impact on the environment, depleting natural resources and producing massive amounts of waste.
Concrete structures are weakened by exposure to water, salt and other chemicals. These elements penetrate the concrete surface to reach the steel reinforcing, causing corrosion and internal damage that can eventually lead to failure. This type of damage is the most common reason for concrete repairs.
When repairing damaged concrete, it’s important to ensure that the new material is properly cured. Long moist-curing times are essential for achieving adequate strength and durability. Insufficient curing can weaken the bond between the new and old concrete, causing it to crack or become loose.
Whether you’re building a commercial or residential concrete project, there are some things that every contractor should know about maintaining the integrity of their structure. Avoid these common mistakes to get the most out of your concrete repair projects. This will save you time, money and prevent future problems down the road.
