How Cracks Affect Concrete Repair
Like we show our age with wrinkles, concrete shows its wear and tear through cracks. A variety of reasons can cause these and can cause safety concerns. Before any repair work is done, the concrete structure must be evaluated, and the cause of deterioration identified. This will help determine the best repair method. Read on Concrete Contractors Dallas TX to learn more.
Cracks are a natural part of concrete repair, ranging from non-structural to structurally damaging. Drying shrinkage, temperature changes, lateral loading, and soil instability can cause cracks. Identifying the type of crack is critical for determining what concrete repair steps are required.
For dormant cracks (cracks that appear to have stopped growing or moving), a simple band-aid fix is to mix a polymer cement product in a bucket with water and wipe the mud over the crack. This is a cheap and quick solution but is a short-term repair. A better option is to use a concrete crack filler that can be applied with a caulk gun, bottle or pre-mixed compound. This product will not only repair the crack, but it also helps to prevent moisture intrusion and protect the crack from further damage.
To prepare the surface for the crack repair product, a wire brush or stiff-bristle brush should be used to scrub the crack area and broom to remove any loose particles. It is also a good idea to blow out the cracks using compressed air. If the cracks are contaminated with oil or grease, it is recommended that they be cleaned by a pressure washer and degreased with an appropriate solvent like mineral spirits.
For active cracks, the process is slightly different. First, a concrete bonding adhesive should be applied to the crack. This will ensure that the crack sealer/crack filler adheres to the existing concrete. Then, a foam backer rod should be stuffed into the crack to a depth of about 1/4 inch. This will help to support the crack repair material and will reduce any “creep” of the filler down into the crack.
Once the crack is ready to be repaired, a clean concrete crack repair product should be applied according to the manufacturer’s instructions. If using a latex-based product, it is recommended that a rubber glove be worn during application as the cleaners can irritate skin. Alternatively, a polyurethane-based product should be used. This offers superior clean-up with acetone and provides a more resilient crack repair that will last for years.
Concrete is a durable material but it can become less effective over time due to environmental factors. Damaged concrete surfaces can cause accidents and lead to serious safety issues. Hence, it is important to repair these damaged areas as soon as they appear. This can help prevent further damage and increase the lifespan of the concrete surface. It also improves the aesthetics of the property and can increase its value.
If the hole is caused by corrosion, it can be repaired with concrete patching materials that are available in hardware stores. However, if the holes are caused by cracks then a more substantial solution is required. The cracks can be filled with cement patching products or epoxy resin. This is a more permanent solution to concrete damage as it repairs the actual structure of the surface.
To prepare the area to be repaired, brush away any loose debris and clean with a water-dampened cloth or sponge. Then, sweep the area and if necessary use a hammer and chisel to remove any rough edges of the hole. It is then a good idea to pressure wash the area to ensure that there are no contaminants left in the concrete before starting to repair it.
Before repairing the hole, mix up the concrete patching product to a ‘clay’ consistency as per the instructions on the package. Once ready, place the concrete patching material into the hole and smooth it out using a putty knife or margin trowel. Once the surface is even, swipe a steel trowel across it to make it level with the surrounding concrete and allow to cure for 48 hours.
A polymer-modified concrete patching material is a good choice for larger areas of spalling and pitting, or where the patch will need to be shaped (such as the edge of a concrete driveway apron). A brand such as Ardex makes an excellent product in this category. This is a more costly option than a standard concrete patch, but it is worth the investment to keep your concrete looking its best. In fact, it is the only way to guarantee that your concrete will last for as long as possible.
Concrete defects directly affect the life and performance of a concrete structure. Therefore, it is important to repair them as soon as possible. This ensures that the building is safe to occupy and provides its intended service.
Concrete surface defects can be caused by a number of factors. These include poor quality materials, incorrect construction techniques, and improper curing. These issues may lead to premature deterioration of the concrete surface, and can result in costly repairs or replacements.
One common type of concrete defect is shrinkage cracking. This occurs when the concrete is exposed to sudden changes in moisture content. These changes can be due to a change in the water-cement ratio, or they may be caused by curing methods that are too fast. Shrinkage cracks are a common problem in commercial buildings and can cause trip hazards and structural damage.
Another common type of defect is crazing, which is a fine crack on the surface of the concrete. This problem is usually caused by inadequate curing after the initial set of concrete, or by additional laitance on the surface of the concrete. Crazing can be repaired by removing the deteriorated concrete and replacing it with new concrete.
Discoloration is also a common problem with concrete. This can appear as stains, spots, or blotches on the surface of the concrete. The coloration is generally caused by chemical variations in admixtures, cement alkalis, and hard troweling. However, it can also be caused by environmental conditions like a wet substrate under the concrete slab or a change in water-cement ratio during construction. Discoloration is not usually a serious issue, and it can be prevented by following best practices for mixing, laying, and finishing concrete.
Other common defects in concrete are blistering, dusting, delamination, efflorescence, scaling and spalling. These problems can be caused by a number of factors, including errors in loading criteria and design, unexpected overloading, and damage from fire, floods, earthquakes, and cyclones. It is also important to protect concrete from excessive exposure to chlorides, which can cause corrosion and weaken the structure.
The surface of the concrete must be prepared prior to the application of repair materials. Many different types of surface preparation methods are used, ranging from chemical cleaning and acid etching to mechanical methods such as shotblasting, scarifying or scabbling. It is important to select a method that will remove existing coatings, clean the concrete substrate and achieve a proper surface profile. The International Concrete Repair Institute (ICRI) has defined nine different guidelines for the proper surface profile, known as a concrete surface profile (CSP). Replica blocks are available to give contractors a visual point of reference to help them determine if a CSP exists.
The substrate should be free of loose material, dust and grease. In addition, the surface must be dampened prior to the application of any cement-based repair product. This is to ensure that the repair will bond well with the concrete surface. Moisture also helps prevent cracking of the repair material and increases the rate at which it reaches full strength.
It is also important to know the proper size of a concrete repair mix for the project. Generally, the amount of water to be added to a concrete repair mix will depend on the condition of the substrate and the type of repair product being used. Most repair products require less water than the concrete it is being poured to, which reduces shrinkage and helps the material bind with the existing concrete.
Cracks that are wet or contain silt should be rout and sealed. This can be done with most epoxy, polyurethane or mortar crack repair products. For structural repair, moisture tolerant epoxy materials can be injected into wet cracks to maintain their integrity and support the existing concrete structure.
Once the cracks are filled, they should be re-sealed using a high quality, long-lasting sealant. This is to keep out weather and other contaminants that can cause deterioration of the repaired crack.
Spalled areas of concrete can be repaired with a quick-setting Mapecem 100 product. It is a cost-efficient solution for resurfacing or leveling floors; repairing trenches, voids and honeycombs; and treating concrete defects. Mapecem 100 can be used for small or large repairs and is cured in three to four hours.