Answer: Damaged concrete can happen for a variety of reasons. Although it is easy to blame contractor error or poor craftsmanship, this is the least likely reason for the concretes poor performance. The rise in spalled or pitted concrete has a lot to do with the change in weather patterns, specifically, freeze-thaw cycles. Over the past ten years, many parts of North America have changed from 3-5 times a year that the snow melts and then refreezes. Long lasting frozen periods do not affect concrete the way melting snow and ice and the refreezing process. In many cities, freeze-thaw cycles have tripled or quadrupled.
With the increase in freeze-thaw, very little has been done to protect the concrete from ice forming inside the cement and aggregate from the melting process. When water is absorbed by melting snow and then freezes it expands by 10%. Therefore this expansion causes the top part of the concrete to pop off or spall. Deicing agents can also eat at the cement in concrete, deteriorating it and causing pits to appear as the bonding agents between the cement and aggregate disappear. To help prevent this many seals there concrete once per year with a product like HS-240. The use of a lithium densifier that does not carry a publishable sealer, like LD 1800, can help strengthen damaged concrete.

Cracks in the concrete are always an eyesore. Identifying what type of break you will determine the correct products to treat it and minimize its recurrence. In this instance, we are not talking about control joints, only cracks that happen in-between control joints. The two types of cracks are active or static. Static breaks are no longer moving. In many cases, they may be viewed as hairline cracks but can be as wide as 1/2 inch. Active cracks can start as a hairline, but continue to widen as the slab is now two pieces of concrete separating farther from each other.

There are no treatments available to stop an “active” crack. The reason for this is due to the mass of each slab bearing too much on a thin material to keep it together. No longer active breaks, static, and hairline cracks can be treated in most cases. Depending on some linear feet and time to complete the process the user can use a cement, urethane, or an epoxy cracks treatment.

Whether it was the slump of the concrete, a bad mix, improper screening/floating, age, or a direct cause of de-icing agents penetrating the concrete surface, spalling concrete is an eyesore and an issue that needs attention. When you factor in labor, time and material costs, the question becomes: can you create an affordable, realistic solution for the conditions that initially caused the concrete to spall? Can the concrete restoration system also be environmentally friendly? Surecrete’s concrete restoration system provides answers to both questions. Let’s look at what products are involved and why they are recommended.

Concrete Restore and Repair
Step 1 – Removing the spalled or damaged concrete surface and cleaning.

Most contractors will begin with an aggressive pressure washing or be scarifying of the concrete surface. The goal of this process is to remove all loose concrete and create a sound surface. An oscillating turbo tip and a pressure washer of 3,500 psi or higher will be sufficient. Using SureCrete’s SCR will clean, mildly de-grease, etch and profile the surface preparing it for your slip-resistant thin concrete overlay. This product is environmentally friendly and will not harm plant life when rinsing the product off. A typical application is a 2-1 ratio of water to SCR.

Step 2 – How to hibernate unseen or future spalling and provide strength to damaged concrete.

Prevention of further damage to the spalling concrete is not an exact science. A sound option for prevention is the use of a Lithium densifier. Why use Lithium Densifier? Use of Surecrete’s LD 1800 (lithium densifier) will harden and increase the surface PSI, slow moisture migration both south and north, and slow and in most cases stop efflorescence. Use of conventional sodium or potassium sodium hardeners is not recommended as they may leave a high concentration of salts deposited on the surface of the concrete and may add to new surface cracking or scaling.

Step 3 – Address any pitting, spalling or patch thicker than a 1/8th inch and repair the concrete slab.

There are many quick patch concrete bag mixes, each varying in price. SureCrete’s Flash Patch is an ideal material choice for patching concrete or filling in damaged spalled areas. The reason for this is the fact that in many areas freeze-thaw can cause delamination of specific, concrete patch material. Flash Patch gives you the strength and speed of hydraulic cement, the work time of 15-20 minutes and a premixed bonding agent to overcome freeze-thaw bonding. Couple that with a compressive strength of 6,200 PSI, Zero VOC, and single component, there is not another bag mix that compares in quality, durability or consistency.

In addition to those attributes, this material allows you to patch all areas of the spalled concrete surface. Once applied your wait time is a matter of 15-30 minutes, then you can begin using slip-resistant thin concrete overlay.

Step 4 – How to choose and apply a slip-resistant thin concrete overlay.

Are you looking for a fresh broomed concrete surface or would you like to upgrade your concrete look and go with a decorative concrete pattern or texture? If you chose a crisp broom finish, SureBroom is the smart choice. SureBroom is a single component (just add water) mix, Zero VOC thin concrete overlay that delivers a fast cure time and a compressive strength of 6100 PSI. SureCrete suggests a two coat process as each coat is about 1/16th of an inch and will not completely cover over minor spalled damage. The second coat will bring the damaged spalled concrete surface back to smooth. The tools you need to apply SureBroom are metal squeegee, horsehair or nylon horsehair concrete broom, mixing paddle on drill and a 5-gallon empty pail to blend in. This system delivers simplicity of technique and a low material cost without compromising strength, quality or longevity of your new slip-resistant thin concrete overlay coating.

Step 5 – Choosing a quality concrete sealer to protect against damage & weather.

Most contractors prefer the use of a solvent acrylic sealer. The reason for this choice is that a quality solvent acrylic sealer will provide deep penetration into the concrete and increase adhesion. If applied to the correct thickness, it will minimize the slicking off of the slip-resistant thin concrete overlay that was used to the spalled concrete surface. Which concrete sealer do you choose? We suggest a solvent acrylic sealer with 20% solids. SureSeal Pigmented or HS 260 will deliver the needed attributes and aid in repelling deicing agents and preserving the slip-resistant thin concrete overlay from spalling and other causes which deteriorate the surface.

A common question after the application is how often we should reapply sealer? We would love to give a reliable timetable for 2-5 years, but the simple fact is many factors come into play that de-grease the lifespan of a sealer. How can you tell if your sealant is weakening? Try a water test. When water is applied to the surface, it should bead up as water would on a waxed surface. If the water beads your protection is still sound. If you desire to keep, the clean, shiny look of your surface reapplies a single coat of a quality 20% solid solvent acrylic sealer like SureCrete’s HS 260.