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How To Deal with Concrete Crazing In Parking Lot Flatwork?

Key Takeaways:

  1. Concrete crazing is a type of cracking that occurs due to the contraction of the surface layer caused by shrinkage, typically hexagonal in shape and no larger than 40 mm.
  2. Causes for the concrete craze include poor mix design, excessive water in concrete, improper curing practices, hot weather during placement/curing, overworking concrete, or wrong ratios between water and cement content.
  3. It is important to ensure proper treatment according to industry standards and use a durable mix with correct proportions to fix crazing.
  4. Proper curing must also be practiced, while sources of moisture should be eliminated when possible.
  5. Resurfacing costs an average of $3-$5 per square foot, while installing a new driveway can cost anywhere from 2-7K, depending on size. Repairs are usually no more than 3.5K if needed.

Have you ever seen those spidery lines on concrete parking lots and wondered what they are? They’re called crazing, and while they may not look like much, they can be a big problem for businesses and homeowners. Several factors, including weathering, stress, poor-quality concrete, and more, cause concrete crazing. Left untreated can lead to cracking, pitting, and other damage. But don’t worry – there are ways to deal with crazing before it gets out of hand. In this blog post, Action Construction Asphalt & Concrete will show you how to identify concrete crazing and what you can do to prevent or repair it.

Concrete Crazing: What Is It?

Have you ever noticed random cracks or fissures on concrete floors? That is specifically known as concrete crazing, which occurs due to the contraction of the surface layer caused by shrinkage. It often results from improper conditions and curing procedures when laying or finishing a concrete floor.

Crazing is known to be caused by the shrinkage of concrete surfaces due to rapid drying or cooling. It commonly occurs when the surface has been exposed during placement to a low humidity setting, high air temperature, baking sun rays, or just any combination of these factors.

Typically, the hexagonal shapes enclosed by crazing cracks do not exceed 40 mm in size. Strangely enough, they can be as small as 20 mm on rare occasions. Generally speaking, these fractures appear shortly after placement and are visible immediately or within a week of installation.

Subsurface concrete cracking phenomena are usually not noticeable until the surface has been wetted and is beginning to dry out. Fortunately, these cracks don’t influence the structural integrity of concrete, rarely affecting its durability or wear resistance.

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A List of What Causes Concrete Craze

1. Poor Concrete Mix Design

A concrete mix must have the right proportions of cement, aggregates, and water to achieve an optimal balance between strength and workability. Suppose these ingredients are not in the correct ratio or improperly incorporated into the mixture. In that case, it can lead to premature cracking, known as crazing.

2. Excessive Water in The Concrete

Too much water degrades the strength and durability of concrete, making it more prone to crazing. This is especially true if a faster-setting type of cement (e.g., high-early-strength) is used, which can cause shrinkage cracks to form before the concrete has had enough time to cure fully.

3. Poor Curing Practices

Concrete needs time and moisture to cure properly, so inadequate or improper curing procedures may lead to craze on concrete parking lot surfaces. Inadequate curing can cause discoloration, dusting, scaling, and spalling problems.

4. Hot Weather During Placement and Curing

Excessive exposure to hot and dry weather during placement and curing can trigger concrete crazing. Hot weather accelerates the rate of hydration of cement particles, causing shrinkage cracks in concrete.

5. Overworking Concrete

It would help if you avoided excessive troweling of the concrete surface or using a high-powered pressure washer on the concrete. These activities may cause crazing by forcing moisture out too quickly or creating an uneven surface texture.

6. Wrong Concrete-Water Ratio

Concrete mix with a higher water-cement ratio will lead to greater shrinkage and increased chances of concrete crazing. Ideally, the water-cement ratio should be between 0.4 and 0.6 for every 1 kg of cement content in the concrete mix.

7. Poor Surface Preparation

Suppose there’s an existing slab that is cracked or otherwise damaged. In that case, you must properly repair it before pouring new concrete over it to avoid cracking caused by underlying problems like subgrade swelling or unequal settling of foundation layers.

8. Carbonation

Concrete carbonation occurs when carbon dioxide from the air combines with moisture in concrete and infiltrates the concrete, reducing its alkalinity. This causes a decrease in pH level, leading to corrosion of reinforcements and an increased risk of cracking due to concrete crazing.

Also Read: 5 Concrete Patio Finishes That Will WOW Your Guests

Dealing with Concrete Crazing:

People can fix anything with the right approach. Concrete crazing can be prevented or fixed by following some simple steps.

  • Make sure your concrete is being treated correctly and according to industry standards.
  • Use a good quality, durable concrete mix that meets the structural requirements of your application.
  • Ensure proper curing of the concrete after it is poured to ensure its strength and consistency.
  • Seal any cracks or damaged areas with an appropriate sealer to prevent further damage from water infiltration and freeze-thaw cycles.
  • In the case of existing slabs, repair any underlying problems before pouring new concrete over them to avoid cracking caused by subgrade swelling or unequal settling of foundation layers.
  • Eliminate sources of moisture that may contribute to carbonation or chemical attack of the concrete.
  • Check for existing water sources that could affect pavement stability, such as drainage and plumbing lines, tree roots, and other similar sources.
  • Do not use deicing chemicals in concrete parking lots more often than necessary.

Rough Repair Cost of Concrete Crazed Driveways

Resurfacing your driveway is a much more affordable way to go than having an entirely new one installed. On average, you can expect resurfacing costs of $3-$5 per square foot; therefore, the median price for an approximate 38-by-16-foot driveway would be around $2,500. If you decide on installing a brand-new concrete driveway, though, that could cost anywhere between $2,500 and up to 7K! However, if just some repairs are needed, you’ll pay no more than 3.5K.

Looking To Get Your Concrete Work Repaired in Austin, TX? We Can Help!

Operating within the concrete industry can be arduous, with various issues that could ruin any job. Yet, preparation remains paramount for all its key components; it is essential to meticulously remove existing structures, even out erratic surfaces, and guarantee everything’s level before pouring concrete.

Action Construction Asphalt & Concrete is the premier provider of concrete services for businesses, homes, and municipalities in Austin, TX. We specialize in paving projects such as driveways or concrete parking lots, repairing cracks on existing sidewalks or patios, resurfacing decks with decorative stamped/patterned concrete, and more! With our experienced staff and top-notch quality service, you can trust that your job will be done right every time.

Get your free quote today.