how to repair concrete scaling

Repairing Concrete Scaling

• Remove loose concrete and clean the surface of any dirt and debris.
• Dampen the cleaned concrete area and apply a thin layer of cement paste before concrete placement for resurfacing.
• Place proper concrete type to resurface the damaged area. Latex-modified concrete (polymer-modified cement concrete) is...
• Apply pressure on the concrete while th...

Full Answer

How to fix and prevent scaling concrete?

Preventive Measures

• Design concrete mix properly; use appropriate water-cement ratio (maximum 0.45) and well-graded aggregate.
• Use a suitable curing method.
• The curing period should be long enough (minimum seven days) for concrete to gain a strength (27 MPa or 70% of design strength) that can resist scaling.

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How to use resurfacing cement on top of concrete?

Step 3: Spread the Resurfacer

• Fill the walkway joints with peel-and-stick foam weatherstripping, and dampen the concrete if necessary.
• The resurfacer is workable for about 20 minutes, so mix just half a bag of powder with 5½ cups of water at a time. ...
• Pour it on the walk.

How to repair and resurface concrete steps?

Steps to Concrete Driveway Resurfacing

• Cost of concrete driveway resurfacing. Concrete driveway resurfacing is an excellent way to upgrade the look of your home. ...
• Preparation required for resurfacing. If you plan to resurface your concrete driveway, you’ll first need to prepare the surface thoroughly.
• Imprinted concrete resurfacing. ...
• Cost of concrete pool deck resurfacing. ...

How to fix spalling concrete?

• When the spalling damage is less than 1/3 of the concrete's thickness, a surface repair is typically possible. ...
• Due to exposure, corroded rebar must be cleansed at the start of the repair procedure. ...
• A cementitious overlay can be used to repair damage on driveways, sidewalks, and other horizontal surfaces. ...

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How do you repair scaling on a concrete driveway?

1:162:47Concrete Surfaces Spalling - Sherwin-Williams - YouTubeYouTubeStart of suggested clipEnd of suggested clipWorth the slurry as a bond coat into the area of being patched. But avoid overworking this singleMoreWorth the slurry as a bond coat into the area of being patched. But avoid overworking this single component patching compound sets. In a half hour for fast return to service.

How do you fix flaking concrete?

Spalled concrete may be caused by any of the following: Freeze-thaw cycles. De-icing salts....If your concrete is spalling, these are the repair options:Patch the spalled area with a color matching compound.Have your concrete resurfaced with an overlay.Rip out and replace the entire slab.

Why is my concrete scaling?

Scaling is caused when water freezes in the pores and capillaries in concrete. When the hydraulic pressure of the expanding ice exceeds the tensile strength of the concrete, scales of mortar detach from the surface, exposing aggregate.

What does concrete scaling look like?

Scaling is flaking or peeling of a finished hardened concrete surface as a result of exposure to cycles of freezing and thawing. Generally it starts as localized small patches, which later may merge and extend to expose large areas. Light scaling does not expose the coarse aggregate.

Can you resurface crumbling concrete?

You can repair and resurface your spalled concrete in any number of ways. You can buy products that apply a very thin coating on the concrete. The larger premixed bagged concrete manufacturers make these, as do some other specialty companies. These products do work, but pay close attention to their limitations.

How do you repair scaling?

Repairing Concrete ScalingRemove loose concrete and clean the surface of any dirt and debris.Dampen the cleaned concrete area and apply a thin layer of cement paste before concrete placement for resurfacing.Place proper concrete type to resurface the damaged area.More items...•

Why is top layer of concrete flaking off?

Damage will show up when the concrete is exposed to ice or snow which then melts and penetrates into the concrete and freezes. Frozen water expands about 10%, pushing the thin, weak top layer upwards causing the layer to peel off (known as spalling).

What does spalling concrete look like?

Spalling concrete can look like round or oval depressions along surfaces or joints. Spalling tends to be most common in cold climates when de-icing chemicals are applied or when seasonal freeze-thaw cycles damage the concrete.

Can you repair pitted concrete?

Once the surface begins to pit, filling the divots with concrete is usually a temporary fix that loosens over time. You can fill pits with a bonding concrete repair material, which is similar to caulk. Restoring the porch to a more original appearance requires dressing it with a special resurfacing concrete mixture.

How do you resurface concrete?

0:454:28How to Resurface Concrete - YouTubeYouTubeStart of suggested clipEnd of suggested clipBefore resurfacing your slab deeply spalled areas and large cracks should be repaired using concreteMoreBefore resurfacing your slab deeply spalled areas and large cracks should be repaired using concrete resurfacer that has been mixed to a triable consistency.

How do you fix salt damaged concrete?

3:5714:21How To Repair And Resurface Spalled, Salt Damaged ConcreteYouTubeStart of suggested clipEnd of suggested clipAll right so what i'm using for the patch material is ardex cd the cd stands for concrete dressing.MoreAll right so what i'm using for the patch material is ardex cd the cd stands for concrete dressing. And this is the same stuff i'm going to use to resurface.

Is spalling the same as cracking?

What is spalling? Spalling is a term used to describe areas of concrete which have cracked and delaminated from the substrate. There are a number of reasons why spalling occurs including freeze thaw cycling, the expansive effects of Alkali Silica Reaction or exposure to fire.

Why is my concrete flaking off?

When the temperature drops below freezing, moisture in the concrete tends to expand, creating internal pressure. Over the course of a winter, or over the course of years, as the internal pressure rises and falls, it stresses the surface layer of the concrete, which leads to spalling.

Why is my concrete floor flaking?

There are a number of reasons why spalling occurs including freeze thaw cycling, the expansive effects of Alkali Silica Reaction or exposure to fire. However, the most common cause of spalling is the corrosion of embedded steel reinforcement bars or steel sections.

Why is my new cement flaking?

If your driveway surface has spalling concrete, the most likely cause is an installation mistake. Common mistakes include adding too much water to the mix, to make it easier to pour; sprinkling the surface of the concrete with water, to extend finishing time; and not curing the concrete properly after installation.

Why is my concrete crumbling?

If too much water is introduced to the mixture, the cement and sand cannot bond with each other and will instead fall apart. As the concrete starts to dry, this results in a crumbling area where the particles aren't sticking together.

What does scaling mean in concrete?

The American Concrete Institute (ACI) defines scaling as the “local flaking or peeling away of the near-surface portion of hardened concrete or mortar.”. It looks like the inside of the slab has pushed up to peel away the smooth concrete surface area.

What causes concrete to scale?

Prominent causes of scaling include: Poor quality concrete, meaning that the water/cement ratio may be greater than 0.50; a localized area in which the contractor poured at an excessive slump; overworking of wet concrete and/or premature finishing operations by the contractor; or inadequate curing.

Can you order concrete with no air entrainment?

So the contractor may have ordered concrete with no air entrainment. As the floor sat exposed, the concrete slab near the window opening may have frozen and become distressed.

Is moisture saturated concrete more susceptible to freezing?

Another factor is inadequate slope to drain water away from the slab. Moisture-saturated concrete is more susceptible to damage from freezing and thawing than drier concrete.

What is a scaling concrete?

Scaling Concrete. 1. What is Scaling? Scaling is flaking or peeling of a finished hardened concrete surface as a result of exposure to cycles of freezing and thawing. Generally it starts as localized small patches, which later may merge and extend to expose large areas.

Why does concrete scale?

Why Do Concrete Surfaces Scale? Concrete slabs exposed to freezing and thawing in the presence of moisture and/or deicing salts are susceptible to scaling. Most scaling is caused by: The use of non-air-entrained concrete or too little entrained air.

How long should concrete be dry before sealing?

The concrete should be reasonably dry, prior to the application of a sealer. CSA recommends a one month drying period following curing. Late summer with at least 1 month of drying post-curing preceding application of the sealer is ideal.

Why is it important to cure concrete?

Curing ensures proper hydration (reaction of cement and water), which allows the concrete to achieve its highest potential strength. Protect concrete from the harsh winter environment. It is important to protect the young concrete from becoming saturated with water, prior to freeze and thaw cycles of the winter months.

What happens when you bleed water back into the top of a slab?

If bleed water is worked back into the top of the slab, a very high water-cement ratio and, therefore, a low strength surface layer is produced. Insufficient or no curing. This omission often results in a weak surface skin, which will scale if it is exposed to freezing and thawing in the presence of moisture and de-icing salts. 3.

Does light scaling expose coarse aggregate?

Light scaling does not expose the coarse aggregate. Moderate scaling exposes the aggregate and may involve loss of up to 2.5 to 10mm of the surface mortar. When severe scaling occurs the coarse aggregate is clearly exposed and some of it may eventually pop out.

Can you use calcium sulfate on concrete?

DO NOT use deicing salts, such as calcium, magnesium or sodium chloride, on new or recently placed concrete. Use clean sand for traction. Never use ammonium sulphate or ammonium nitrate (i.e. fertilizers) as a deicer; these are chemically aggressive and destroy concrete surfaces.

How to get a nice finish on concrete?

Timing is the secret to getting a nice finish. Use the bull float immediately, but wait until the concrete stiffens before using the edger and broom. All the tools you need are available at most rental stores. Cover the finished concrete with plastic for five days or spray it with a curing compound.

Why is my driveway spalling?

Common mistakes include adding too much water to the mix, to make it easier to pour; sprinkling the surface of the concrete with water, to extend finishing time; and not curing the concrete properly after installation.

How to make a cement wheelbarrow?

Mix one part Type 1 Portland cement and one part fine sand by volume. Add water until the mixture is the consistency of thick paint, then brush it on the damp concrete. Before that dries, mix three parts fine sand and one part Portland cement in your wheelbarrow with enough water to make the mix the consistency of thick oatmeal.

How to prevent concrete from spalling?

HOW TO PREVENT CONCRETE SPALLING. Sealing is the best way to prevent moisture-related spalling. For new concrete, apply a penetrating waterproofing sealer 28 days after concrete placement and every few years thereafter. The correct concrete mix can also help prevent spalling.

Why is my concrete cracking?

Shrinkage cracking is caused by rapid drying of the concrete surface by wind or high heat. Proper placement and curing practices are required to prevent this. Spalling is caused by one or more of the following: a poor concrete mix, poor finishing, or overwatering.

What is a gray stamped concrete driveway?

A gray-colored stamped concrete driveway was poured for a front entrance to a motel. The driveway is exposed to a cold climate and developed etching, cracking, and minor spalling within a year. No deicing salts were used. What could be the causes?

What is spalling concrete?

Spalling concrete is a common problem where part of the surface peels, breaks or chips away. Also known as scaling, it is the result of a weak surface that is susceptible to damage. Spalled concrete may be caused by any of the following: If your concrete is spalling, these are the repair options: Find contractors that specialize in concrete ...

What causes the water in the capillaries of concrete to expand?

Freezing causes the water in the capillaries of the concrete to expand, creating pressure. Over time, the expansive pressure from repeated cycles of freezing and thawing can break away the top surface of the concrete, leaving pit marks and exposing the coarse aggregate.

Does concrete mix help prevent spalling?

The correct concrete mix can also help prevent spalling . Air entrainment is particularly effective in providing resistance to freeze-thaw cycles. When the moisture in concrete freezes, these air cells relieve internal pressure by providing microscopic chambers for the expansion of water as it freezes.

Why does concrete scale?

The most common causes of scaling are listed below. Non- or Low-Air-Entrained Concrete – Air- entrained concrete contains small voids which accommodate volume changes when water ( i.e. precipitation) in the concrete freezes and expands. If the concrete is not properly air entrained, the concrete surface may be overcome by expansive forces ...

What happens if you bleed water on concrete?

Poor Finishing – Overworked concrete surfaces or those that receive additional water and or finished with bleed water can result in reduced entrained air content or weak, thin, cementitious paste deposits at surfaces. Repairing scaled concrete surfaces can prove difficult.

Can you repair scaled concrete?

Repairing scaled concrete surfaces can prove difficult. If a proper bond is not achieved between the cementitious topping/overlay and the underlying concrete, additional scaling or delamination may occur. If scaling is prevalent in your community, contact a professional engineer to determine the extent of the damage and to develop ...

What causes concrete to spalt?

Over the course of a winter, or over the course of years, as the internal pressure rises and falls, it stresses the surface layer of the concrete, which leads to spalling. The fix typically involves nothing more than applying ...

What is Rapid Set Newcrete?

Specially formulated to restore lackluster concrete, resurfacing products like Rapid Set NewCrete ( available from The Home Depot) make it quick and easy for homeowners to address spalling on their own, without having to hire a contractor. The resurfacing material simply spreads over the existing, spalled concrete surface to create a fresh, flawless finish.

Does Newcrete require primer?

NewCrete in particular stands out, because it simplifies and speeds up the process. For one thing, it rarely requires the use of primer.

Can you mist a driveway with resurfacer?

In especially dry, windy, or hot conditions, it may be necessary to mist the area while the resurfacer gains strength . But if you’ve chosen the right day for the project, you can apply resurfacer, drive off to do errands, and then return a little later and park your car on a pristine, perfectly smooth driveway.

What Is Scaling?

Why Do Concrete Surfaces Scale?

How to Prevent Scaling

How to Repair Scaled Surfaces