The Complete Guide to Driveway Paving for 2018
Table of Contents
- Asphalt Driveway Overview
- Advantages of Using Asphalt
- What is Asphalt Made Of?
- Asphalt Driveway Installation
- Common Wear and Tear Issues
- Asphalt Driveways: Bottom Line
- Asphalt Repair Overview
- Types of Asphalt Cracks
- Routine Maintenance Requirements
- Asphalt Repair: Bottom Line
- Concrete Driveway Overview
- What is Concrete Made Of?
- The Unbeatable Strength of Concrete
- Benefits of Concrete Driveways
- How is a Concrete Driveway Installed?
- Stamped Concrete
- Concrete Pavers/Paving Stone Driveways
- Stained Concrete
- Concrete Driveways: Bottom Line
- Concrete Repair Overview
- Why Does Concrete Crack?
- Types of Concrete Cracks
- Concrete Repair: Bottom Line
- Paving Costs Overview
- How Much Does an Asphalt Driveway Cost in 2018?
- How Much Does a Concrete Driveway Cost in 2018?
- How Much Does It Cost To Repair a Driveway in 2018?
- How Much Does Asphalt Sealcoating Cost in 2018?
- How Much Does a Concrete Sidewalk or Pathway Cost in 2018?
- How Much Does a Stamped Concrete Installation Cost in 2018?
Driveway Paving Overview
That's why your driveway is one of the most important elements of your home's exterior and can literally make or break the overall look and feel of your property.
A beautifully paved asphalt, poured concrete, or paver (aka "paving stone") driveway will not only increase the value of your property, but also give your home a memorable – and lasting – first impression.
To help you make a well-informed decision about which material will be the best choice for your driveway paving installation, below are some key points about these common types of paving surfaces:
Asphalt vs. Concrete Driveways
|ASPHALT DRIVEWAYS||CONCRETE DRIVEWAYS||PAVER DRIVEWAYS|
|Less expensive but requires more upkeep. Average cost $3-$6 per square foot.||More expensive but requires less upkeep. Average cost $4-$10 per square foot.||Most expensive but requires the least upkeep. Average cost $5-$20 per square foot.|
|Average lifespan up to 15-20 years with proper maintenance.||Average lifespan up to 25-30 years with proper maintenance.||Average lifespan up to 30-40 years with low maintenance.|
|Easy to repair. Sealcoating recommended every 2-4 years.||Difficult to repair. Should be sealed every 5 years.||Easy to repair and replace with minimal upkeep.|
|Normally installed within 24-48 hours. Ready for use in 1-3 days.||Normally installed within 24-36 hours. Ready for use in 7 days.||Normally installed within about a week for an average-sized driveway.|
|Flexible pavement is less likely to crack and highly weather resistant.||Rigid pavement is extremely durable and exceptionally strong.||Stone pavement is among the most durable surface coverings on the planet.|
|Ideal for colder climates as it melts snow faster, can expand/contract with temperature changes, and won't deteriorate from salt use. Prone to softening in hot climates.||Ideal for warmer climates as it will not overheat and soften in hot temperatures. Prone to cracking from freeze-thaw cycles and salt can damage it.||Ideal for all types of climates, but are particularly useful in areas that get heavy snowfall as they can withstand frequent freezing and thawing cycles.|
|Limited finishing options available but dark color makes it easier to maintain a neat appearance and hide stains.||Many finishing options and colors available but typical light gray surface can stain easily and show every imperfection.||An extensive amount of colors and laying pattern options are available to customize a look to suit any home's exterior.|
Asphalt Driveway Overview
Also known as "blacktop", this beloved surface covering is a frequent choice for a wide variety of commercial and residential applications from parking lots and driveways, to interstate highways and airport runways.
When you consider the many benefits of using this smooth, quiet, durable, sustainable, and budget-friendly material, it's not hard to see why so many people choose asphalt as a top-shelf paving option.
Advantages of Using Asphalt for Driveway Paving
Whether you're paving a large or small residential driveway, asphalt should be a serious consideration for several important reasons:
1. Fast Installation Time
Asphalt takes far less time to install than concrete, as it does not require the extensive drying and curing time that is common for concrete installations.
On the other hand, laying a concrete driveway would take roughly twice the amount of time, not to mention the additional time it takes for concrete to set and cure. By contrast, most asphalt driveways are ready to go in as little as 2 days after installation.
Due to its high bitumen content (the sticky black substance inside), asphalt is quite flexible making it an excellent surface for supporting and efficiently distributing load stresses.
In addition, your blacktop driveway can be salted in the winter to help the snow melt faster and provide better traction. By contrast, concrete driveways can sometimes be damaged by certain salts or de-icing agents.
While asphalt driveways tend to develop cracks at a slightly higher rate than that of their concrete counterparts, it is far easier (and much less expensive) to repair cracks in blacktop versus concrete.
Your paving contractor can seal any cracks or fissures in the surface of the blacktop using a specialized sealant or emulsified liquid (known as "sealcoating").
3. Heat Retention During Cold Months
In colder climates, an asphalt surface can really demonstrate its usefulness during the winter months because its dark color absorbs sunlight which makes it retain heat. This causes snow to melt much faster than it would on a lighter colored surface.
This means that if your neighborhood were to get hammered by a major blizzard, the snow would melt quicker on your asphalt driveway than it would your neighbor's concrete driveway.
Hey, who knows – maybe if you let the sun shine long enough, you can cut your snow shoveling duties in half by letting your driveway do its thing.
There is a flip side to this, however: During the heat-drenched days of summer, a blacktop driveway is definitely no friend to bare feet!
4. Highly Cost-Effective
Of all the different paving options there are to choose from, asphalt ranks as one of the absolute cheapest to install (aside from gravel).
And since a blacktop driveway can be installed within a quicker time frame than other paving materials (e.g. concrete paving stones), you'll spend less money on labor costs as well.
The budget-friendly nature of asphalt should not only be considered in terms of its installation cost, but also its low long-term maintenance costs as well.
As mentioned earlier, if your blacktop driveway begins to show signs of cracking, you can simply hire a trusted paving professional to seal those cracks for a reasonably low price.
It should be noted that if you just had an asphalt driveway installed, you should not have any sealant applied until at least six to nine months have passed. Otherwise, you can run the risk of damaging the foundation.
Regular upkeep tasks such as sealcoating (every 2-4 years), sweeping, crack filling, and general maintenance can add several years to the lifespan of your asphalt surface, at a lower average cost than that of concrete.
5. Environmentally Sustainable
It is comprised of several different naturally occurring materials (e.g. sand, gravel, bitumen, etc.) that are renewable, making it a prime candidate for recycling.
With the colossal amount of asphalt that is recycled on an annual basis, economists have estimated that it actually saves taxpayers roughly $1.8 billion per year.
Not only can damaged or out-of-service roads be broken up and recycled into new asphalt, but other post-consumer waste products such as old shingles or used tires can be recycled into new blacktop pavement as well.
This high "recyclability" gives asphalt a virtually unlimited life cycle, as it can be used over and over again in a variety of forms or applications.
What is Asphalt Made Of?
One of the main ingredients in asphalt is a naturally occurring material known as bitumen. This black, gummy, viscous liquid is mixed with sand and crushed rocks (often called "mineral aggregate") to form asphalt.
Bitumen is far from a newly discovered material. In fact, this sticky substance was commonly used in the mummification practices of the ancient Egyptians over 5,000 years ago!
Technically speaking, bitumen is known as a "cementitious" material, which is a fancy way of saying that it acts like cement.
Since bitumen is the primary binding agent in asphalt, it is in heavy demand year-round to the tune of over 100 million tons per year.
So where does all of this highly useful material go?
Perhaps not surprisingly, it is also the most recycled material in the U.S. with over 60 million tons being reused or recycled each year.
Compare that with only 2 million tons of plastic being recycled per year, and you can easily see why asphalt is considered to be one of the most sustainable, environmentally friendly materials in use today.
Asphalt Driveway Installation: Quality Matters
When it comes to installing asphalt paving, quality is of the utmost importance. If the job has been done right, the blacktop will be level, smooth, and neat.
A shoddy job, on the other hand, will be evidenced by rough, uneven, and generally unattractive pavement.
For example, you've probably seen paving jobs where it looked like the blacktop was literally dumped and splattered over a given area, with no clean-cut edges or smooth transitions to speak of.
This type of common occurrence should give us a good idea of the workmanship, technique, and skill level that is required to produce a quality asphalt paving job. There are several steps that your paving contractor will carry out in order to install a high-quality blacktop surface.
Below is a general overview of the process:
1. Preparing the Subgrade Area
If the installation is being performed as a new construction, your paving contractor should take great pains to ensure that the soil subgrade has been adequately prepared, graded and compacted, so that the surface is absolutely level.
This may include removing any loose rocks or stones, as well as "soft" soils such as clay or sand.
That doesn't mean that the ground cannot have any slope, as we know that many driveways and other surfaces do sit at an incline.
But the ground must be level in the sense of not having any dips, bumps, or other surface aberrations that could cause problems once the asphalt layers have been applied.
If your contractor will be extending or expanding upon an existing pavement installation, precision saw-cutting or milling techniques may be used to create a smooth transition between the two pavement surfaces.
2. Building the Subbase and Base
Your paving contractor will then build a subbase and base layer (directly above the soil subgrade) using aggregate material such as crushed stone or gravel.
Normally 4-6 inches thick or more, this will provide solid support for not only the asphalt but for the vehicles that will park or drive upon it as well.
In fact, the entire process requires an extreme level of precision and attention to detail, which is why a job like this is always best left to a trained professional.
3. Drainage Considerations
When it comes to blacktop paving installations, water can be a formidable nemesis.
If the installation is done incorrectly, it will be easy for water to collect on the surface of the pavement which can eventually cause potholes, alligator cracking, heaving (formation of ice crystals in the soil beneath the pavement), or even collapsing of the ground beneath the pavement.
Your paving contractor should make the appropriate considerations for water drainage by ensuring that the pavement has the proper slope and grade to facilitate efficient water runoff.
These considerations may include gutters and curbs that will direct water runoff to the appropriate catch basins or storm drains, in order to avoid potential water damage issues.
All of these factors must be taken into account when planning out a paving installation, showing once again why this type of precise and highly detailed work is best carried out by a qualified contractor.
4. Applying the Asphalt
After the base has been built to exacting specifications, your paving contractor will then begin laying down the asphalt.
This process is done in a series of layers known as "courses", where each layer (or course) must be rolled and then carefully compacted to ensure a smooth, evenly-finished product.
Using specialized equipment, the asphalt is heated to a high temperature in order to make it easier to spread across the surface. If the semi-liquid mixture is allowed to cool too much, it will hinder the flexibility of the asphalt, making it difficult to apply an even course.
The thickness of the asphalt pavement will vary depending on the type of vehicles and loads it will support, as well as the condition and thickness of the subbase.
5. Smoothing Out Transitions
Your paving contractor must not only consider the quality of the surface covering itself, but also how it connects with the streets, sidewalks, etc. that surround it.
The last thing you would want is to have a big "hump" or other pronounced inconsistency in these transitions, as they can not only produce a jarring effect but can also hinder the proper drainage of water from the pavement.
One of the most common techniques that your paving contractor might use to smooth out these transitions is a process known as asphalt or pavement "milling", which involves removing and reshaping part of an existing paved surface using a specialized piece of equipment.
6. Applying the Surface Course
This final roll is designed to create a smooth surface that is free from protruding aggregates or other surface irregularities that can hinder the pavement's functionality.
Once this final layer has been applied and the asphalt has time to dry and settle, your pavement installation will be ready for use!
Asphalt Driveways: Common Wear and Tear Issues
As the law of entropy would have it, all asphalt surfaces are subject to wear and tear over time. Many of these issues appear gradually and are nothing out of the ordinary, while others might come rather unexpectedly.
In either case, the most common telltale sign that wear and tear is occurring is when cracks begin to emerge.
Below are some of the most common culprits for cracks in blacktop pavement:
1. Improper Installation
Of all the reasons why asphalt defects can occur, this one has to be the number-one culprit.
One of the most common mistakes made by inexperienced or subpar paving contractors is not adequately compacting the foundation before laying the asphalt.
When this happens, the courses that are laid on top of the foundation don't get the support they need, which will eventually result in cracking and uneven "pockets" developing in the blacktop.
If the pavement begins to display cracking within the first two years of being installed, this is a sure sign of poor installation practices.
2. Ultraviolet (UV) Rays
Asphalt can take a beating from the sun, especially in very hot or arid climates. Interestingly enough, it's not so much the heat from the sun that causes problems for asphalt; rather it's the UV rays that do most of the dirty work.
This natural form of radiation emitted by the sun can zap the moisture right out of asphalt, drying it out and diminishing its natural flexibility.
Your paving contractor has all the tools and equipment necessary to perform this task, so be sure to ask them about this much-needed routine maintenance.
3. Changes in Soil Composition
Not all soil is created equal; some parts of the world have rich soil with a moist composition, while other areas have soil that is mostly comprised of sand or clay.
In areas where the soil composition has a high clay content, you will more than likely have more trouble with an asphalt installation.
The reason for this is that the clay goes through shrinking and expansion cycles due to changing weather conditions. For example, if a particular area is hit with a prolonged drought, this will cause the clay to dry up and shrink.
Once the rain finally comes, the clay will then swell up and expand. This can wreak havoc on pavement by constantly shifting and moving the ground beneath it, eventually weakening the structural integrity of the pavement. Once this happens, cracks are virtually inevitable.
4. Soil Erosion
Soil erosion is a common occurrence in areas where the paved surface is lower than the terrain that surrounds it.
When this occurs, runoff from rainwater will eventually saturate the soil that surrounds the pavement installation, causing water to seep underneath the pavement and disturb the foundation.
5. Damage from Tree Roots
You have to admire Mother Nature, especially when something as unassuming as a tree root can exert enough pressure on pavement to eventually cause cracking or other surface disruptions.
This scenario is quite commonly seen in driveways although sidewalks, streets, and even parking lots can experience damage from tree roots as well.
6. Excessive Weight
One of the first factors that a paving contractor must consider is the type of loads that a paving installation will support. For example, it's obvious that an airport runway designed to support 400-ton jumbo jets is going to need a much stronger foundation than a residential driveway.
7. Freezing and Thawing Cycles
The earth beneath your driveway is not a static thing; it's constantly changing and can be materially affected by factors such as temperature and humidity. This holds especially true in terms of freezing and thawing cycles.
Every time the ground beneath the pavement freezes or thaws, it contracts or expands which can cause the pavement to move or shift. If water penetration happens as a result of these shifts, the damage from cracking can worsen over time.
While there's no way to prevent 100% of the wear and tear that your asphalt pavement might endure, our qualified paving contractors can help you maximize the lifespan of your blacktop through professional installation techniques and proven repair methods.
So whether you're dealing with a cracking problem that came from excessive UV exposure or a pesky tree root, our contractors can get your asphalt installation looking great again!
Asphalt Driveways: Bottom Line
Asphalt is not only a durable and wallet-friendly surface covering, but it also carries a sleek, clean, and modern look that can lend an air of sophistication to virtually any home's exterior.
Traditionally speaking, asphalt only comes in one color (black), but new sealant technology has been developed that offers a variety of color choices.
If you're considering asphalt as a surface covering for your driveway, be sure to connect with an experienced paving contractor to perform the installation. This is the best way to ensure the highest degree of longevity and structural soundness for your driveway installation.
There are dozens of asphalt paving contractors out there, but not all of them provide the same level of service, expertise, and workmanship.
Our trusted contractors understand that the needs of every customer will be different, and they are willing to take the time to thoroughly assess your paving project so that they can make the most appropriate recommendations.
Whether you have a residential, commercial, or industrial project to take care of, you can rest assured that we will connect you with a qualified and experienced contractor to handle the job.
Contact us today to see how we can help you create a stunning asphalt driveway that will stand the test of time.
Asphalt Repair Overview
There are several reasons why asphalt is a fantastic choice for a wide variety of paving jobs. It’s durable, easy to install, environmentally friendly, and not to mention the fact that it’s one of the most inexpensive paving materials on the market.
A properly installed asphalt paving job can provide decades of service but as the old saying goes, nothing lasts forever.
You might start to notice that certain areas of the pavement are beginning to crack, or you could see potholes or other surface irregularities begin to emerge.
Some of these issues may appear gradually over time, while others might take you by surprise. Below are some of the most common asphalt problems to look out for, as well as what your paving contractor can do to help remedy those issues:
Types of Asphalt Cracks: Alligator Cracking
This extremely common pavement problem definitely lives up to its name, since once the blacktop has become riddled with these types of cracks, it can begin to look like the scales on an alligator’s back.
There are a number of reasons why this type of structural failure can occur, including weaknesses in the subgrade or subbase, inadequate drainage, an asphalt surface that is too thin, or some combination of all of these factors.
On paved roads, alligator cracking often starts as longitudinal cracks in the wheel path, but over time it can worsen due to increasing traffic.
Since this type of asphalt defect is the result of a structural failure, your paving contractor will more than likely have to perform what is known as a full-depth patch, which is where the pavement and base below will need to be dug out and rebuilt.
Longitudinal (aka Linear) Cracking
In other words, these cracks will typically be parallel to the edges of the road or driveway.
One of the primary culprits of longitudinal cracking is reflective cracking, which are breaks or cracks in the underlying layers of asphalt.
This is due to movement taking place at the point of the original surface crack. Poor joint construction and/or pavement fatigue are additional reasons why longitudinal cracking can develop.
For this type of paving problem, your contractor will more than likely seal up the cracks up to prevent moisture from seeping down into the subbase. This can only work, however, if the cracks measure no more than half an inch deep.
Any deeper and your paving contractor will probably have to remove the cracked layer of pavement entirely, replacing it with a completely new overlay.
You can think of block cracking as how alligator cracking would look if you were to see it at 10x magnification.
Unlike alligator cracking, however, block cracking is not associated with load stresses. Instead, it is typically caused by shrinkage of the blacktop pavement due to problems with the binding agent that is part of the asphalt mix.
When this binding agent cannot expand and contract with fluctuating temperatures, it creates stress within the asphalt that can basically only be resolved by cracking.
Sometimes this happens due to the way the asphalt mixed at the initial installation. If the mix was too dry when it was placed, it can have this type of effect later down the line.
Block cracking can also be caused by using low-quality asphalt binder, or by mixing low penetration asphalt with fine or absorbent aggregates.
To solve this problem, your paving contractor can seal the cracks but only if they’re less than half one-half inch in depth. If they run deeper than that, your paving contractor will probably have to remove the defective layer and replace it with a fresh overlay.
In this regard, they basically run in the opposite direction of longitudinal cracks.
This type of cracking is usually a symptom of problems with reflective cracking under the surface layer.
Transverse cracks are considered to be a type of thermal cracking because they can sometimes stem from the stresses of daily temperature fluctuations, but they can also be the result of unskilled usage of paving equipment during installation.
In addition, there are cases where transverse cracking can result from the structural failure of an underlying subgrade and/or subbase.
Similar to longitudinal and block cracking, for your paving contractor to fix this they will more than likely seal up the crack as long as it measures less than a half-inch in depth. Any more than that, the entire pavement layer will need to be removed and resurfaced with an overlay.
As the name implies, slippage cracks occur when the surface layer basically “slips” over the underlying layers, creating what in effect are “stretch marks” in the asphalt.
A common reason for this lack of adhesion between layers of pavement is the presence of excessive oils, dirt, or other contaminants that basically block the adhesive from taking hold.
As with many other asphalt repair problems, slippage cracks are usually the result of poor installation practices.
Subpar paving contractors will often fail to apply what is known as a “tack coat” between the asphalt layers as they’re being laid down.
Without this key layer of adhesive material (also called “slow-setting emulsion”), it can be difficult for the previous layer to stay in place as a new one is being laid on top of it.
Your paving contractor will typically fix this type of issue by removing any area where the slippage cracks are found, and then replacing the asphalt with a partial or full-depth patch, depending upon the severity of the problem.
Joint Reflection Cracks
Joint reflection cracks can sometimes occur when a flexible paving material such as asphalt is laid over a rigid paving material like concrete.
In this sense, the cracks are simply reflecting the places where the joints are found in the underlying concrete. By definition, joint reflection cracks do not include reflection cracks that emerge in areas that are apart from the location of the underlying pavement joints.
To repair this issue, your paving contractor will normally seal the cracks so that water won’t be able to seep down into the subgrade.
Once again, the cracks cannot be more than half an inch deep for this to be effective. If the cracks are deeper, the cracked layer of pavement will need to be removed and replaced with an overlay.
They often mimic the path that the pavement edge follows so that if you were to cut off the asphalt at the cracks, you would simply have a narrower pavement path.
Edge cracks are often the result of poor drainage, as well as inadequate support at the edge of the pavement. This can happen due to improperly "tamping" (packing down) the asphalt at the time of installation.
Skilled paving contractors will usually tamp the edges of the asphalt at a 45-degree angle to provide the necessary support for the asphalt layer.
Other common causes for edge cracks are heavy plant growth along the edges and/or heavy traffic. Your paving contractor will usually remedy this situation by first removing any vegetation along the edges and addressing any slow or poor drainage issues.
After that, they will seal or fill the cracks to discourage any further crumbling or deterioration. If necessary, your contractor may also need to reconstruct the pavement area to full width to ensure that any lingering support issues are fixed.
You can often see rutting develop on highly trafficked roads or even on driveways from the wear and tear of studded snow tires.
Rutting is basically a shifting of the subgrade or asphalt pavement layers due to consistent traffic, and it is often caused by a lack of pavement thickness. When rutting happens, it can also produce "shearing" which is the uplifting of pavement along the borders of the rut.
It’s very easy to identify ruts after a rainstorm has passed through the area, as they will often be filled with water. On roadways in particular, puddle-filled ruts can be very dangerous as they can cause hydroplaning due to standing water.
Other common causes for rutting are weak asphalt mixes, lack of compaction of the subgrade, subbase or asphalt itself, or even the presence of moisture in the layers beneath the surface.
If the rutting is stabilized or if it is somewhat minor, your paving contractor can simply fill in the rut and overlay it with fresh asphalt. For more severe rutting scenarios, the entire rutted area will need to be removed and replaced with brand new material.
This expansion creates stress on the asphalt layers, resulting in the pavement being pushed upward and sometimes cracking when cars are driven over it.
Upheaval is quite common in colder climates, as ice "lenses" (layers) forming within the subgrade soil beneath the pavement, begin to expand as long as there’s an available supply of moisture on hand.
These ice layers can siphon water from all directions, even as far away as 20 feet from the main location of the ice lens.
Clay or silt soils are typically more susceptible to upheaval due to inferior drainage qualities, while soils that feature a good combination of sand and gravel can stem the flow of water via capillary action.
To fix this type of issue, your paving contractor will normally have to perform a full-depth patch, replacing not only the irregular asphalt layer but also the layers and subgrade beneath it.
It is not uncommon for shoving to develop in sections of asphalt that also have horizontal stresses, such as where one road meets another.
One of the most common reasons for shoving is excess asphalt being used in the installation by inferior paving contractors.
Other common causes of shoving include using asphalt that is too soft, a weak or insufficient granular base, and/or an asphalt mix that contains excessive quantities of fine aggregate. Shoving can also be caused by excessive moisture content in the subgrade.
Your paving contractor will address shoving problems by performing a partial or full-depth patch, depending upon the severity of the problem.
Like ruts, depressions can fill with water (hence the bird bath reference) and if left in disrepair, they can continue to worsen until they turn into an even bigger surface problem.
Depressions are often caused by settlement in the lower layers of the payment, or some other structural failure that has occurred beneath the surface of the blacktop.
We hate to sound like a broken record here, but depressions are yet another problem that can be traced back to poor installation practices.
Without implementing proper asphalt paving techniques, an unskilled or inexperienced paving contractor can set the stage for depressions and other distortions to develop.
To fix depressions, your paving contractor will first of all assess the severity of the problem. If the depression isn’t that bad, it is possible that only an infrared patch or thin surface patch will be needed.
For severe depressions, more than likely your paving contractor will need to remove and replace the problem area entirely.
In a sense, you could actually rename raveling “unraveling” because that’s essentially what the pavement material is doing – it’s continuing to erode away leaving pock marks, chips, chunks, and an overall jagged appearance in its wake.
There are several reasons why raveling occurs, but one of the most common culprits is – you guessed it – poor installation practices. If an inferior asphalt mix was used, or if the binder was of a poor quality, it can negatively affect the durability of the blacktop surface.
Sometimes there are cases where the asphalt repairs themselves will need to be repaired.
This can be due to a number of factors including poor compaction, the quality of the asphalt mix, and/or the quality of the underlying or surrounding pavement.
Unfortunately, in the world of asphalt repair, there are many unscrupulous contractors who would rather cut corners than do a high-quality job in order to boost their bottom line. As you can see, this doesn’t just apply to the initial installation, but to repair work as well.
Fortunately, an experienced paving contractor can remedy the situation by keeping patch failures from rearing their ugly heads again.
Depending upon the severity of the problem, your paving contractor will perform either a partial or full-depth patch to restore the defective area and bring it back up to the required standard.
Almost everyone is familiar with what these are, especially if you’ve accidentally hit one while you were driving.
Potholes typically have sharp or abrupt edges, and they can wreak havoc on tires and/or front end alignments.
They are often the end result of alligator cracking that has been left unattended. When vehicles roll over this type of area enough times, the persistent pressure can begin to knock chunks of pavement out of the affected area, making the conditions ripe for a pothole to develop.
Common factors that contribute to the formation of potholes include substandard asphalt mixture, weak areas in the subgrade or subbase, and/or using low-quality binding agents.
For this type of extreme surface damage, your paving contractor will need to perform a full-depth replacement patch to repair the damaged asphalt.
Routine Maintenance for Asphalt Installations
Fortunately, keeping blacktop in good working condition is a fairly easy process.
By remembering to consult with your paving contractor for routine maintenance tasks, you can confidently expect the lifespan of your asphalt pavement installation to last up to 15–20 years or more.
This will allow enough time for the blacktop surface to properly cure. At that point, it's a good idea to have your paving professional go over the installation with a high quality pavement sealer, which is a process known as "sealcoating".
This provides a much-needed layer of protection from water penetration and harmful UV rays that can oxidize the surface of the asphalt, making it less flexible and more susceptible to cracking.
Pavement sealer will also protect your blacktop from oil and other chemical liquids that can leak from parked vehicles.
If asphalt is not properly sealed on a periodic basis, it will begin to dry out due to excessive UV exposure, which can cause the pavement to lose its flexibility. When this happens, cracking and accelerated deterioration are basically inevitable.
The exact amount of time will ultimately depend on the overall wear and tear of your asphalt surface and the severity of your climate conditions.
When your paving contractor comes out to perform sealcoating maintenance, they will first need to prepare the asphalt by removing common obstructions such as:
If you’ve ever seen a parking lot, driveway, or even a tennis court that has been neglected for a long time, you will often observe grass growing through the many cracks that have formed in the asphalt.
Of course, pavement jobs that are in such an extreme state of disrepair are typically the result of months or years of performing little to no maintenance.
The ideal scenario is for your paving contractor to clean out the cracks using a heat lance before sealing them, so that grass or other organic debris will not get a chance to grow.
A heat lance is basically a tool that burns out any vegetation while also evaporating moisture and blowing debris and dirt out of the cracks in the blacktop.
2. Oil Spots:
If left unattended, they will eventually eat away at the surface layer of the blacktop, causing damage and eventual deterioration.
Your paving contractor should thoroughly clean these areas before applying the sealant, which will help protect the blacktop from this type of damage in the future.
3. Tree sap, mud, berry stains, dirt, etc:
These types of natural substances can form a barrier between the sealant and the asphalt if the area is not thoroughly cleaned before application.
If there are also any places where the asphalt has experienced structural failure, your paving contractor will apply small asphalt "patches" to those areas to rejuvenate the blacktop and stop further deterioration.
Your paving contractor will then seal up any cracks in the pavement. The sealant is usually applied in one or two coats either with a spray or squeegee, depending on what your paving contractor determines is best for the job.
Asphalt Repair: Bottom Line
Asphalt is one of the most durable paving materials on the planet but as you can see, it is far from invincible. The heavy and consistent use over time will eventually take its toll, which means that your pavement will eventually require some type of repair work.
The best route to go down is consulting with a qualified paving contractor who can assess whatever repair or maintenance needs might be necessary, and then carry them out with top-quality workmanship.
Contact us today to get your pavement installation on the fast road to recovery!
Concrete Driveway Overview
Concrete has long been a popular surface covering for paving installations of all kinds, from major highways to residential driveways and everything in between.
With over 20 billion tons of concrete being put to use every year, it's safe to say that this classic building material has an enduring fan base!
There are many reasons for concrete's popularity: it's exceptionally strong, durable, versatile, and for driveway installations in particular, it is a surface covering that offers aesthetic appeal along with excellent functional value.
What is Concrete Made Of?
Before we go any further, it would be useful to find out what makes this extremely popular material so strong and durable.
Concrete is comprised of three basic "ingredients": Water, aggregate (often gravel, crushed rocks, or sand) and Portland cement.
Cement is actually a powdery substance that acts as a binding agent in the concrete mix.
As soon as cement is combined with the water and aggregate particles, the entire mixture transforms into a semi-solid "slush" that can be poured and manipulated to fill practically any form or shape you desire.
Once this mixture is poured, it will eventually harden into the material that we all know as concrete.
What's interesting is that not only is hardened concrete one of the strongest materials on earth, but as the years go by, it continues to get stronger and harder over time.
One excellent example is the colossal Hoover Dam – even though it was built more than 80 years ago, the concrete in this massive structure is still curing to this day!
The Unbeatable Strength of Concrete
Strength is one of the most prominent reasons why people choose concrete as a paving material for their driveway.
This robust material reaches an average compression strength of around 2,500 to 5,000 psi (pounds per square inch) but there are even some mixes that have a compression strength of up to 20,000 psi.
For the most routine uses (e.g. a driveway), a compression strength of 2,500 to 4,500 psi is typically used which is suitable for bearing the load stresses of most vehicles.
Your paving contractor will be able to tell you whether or not you will need a higher strength rating based on the type of loads that your pavement is intended to bear.
For example, if you're going to keep an RV or some other large, heavy vehicle parked on the driveway, more than likely your paving contractor will recommend a stronger grade of concrete or to increase the thickness of the slab.
In fact, increasing the thickness of a pavement slab by just one inch can increase its load-bearing capability by up to 50 percent!
Believe it or not, sometimes the biggest load stresses do not come from what's on top of the slab but from what's beneath it. Issues such as heaving (swelling due to the expansion of soil) from the subgrade can place incredible stresses on concrete slabs from beneath the surface.
This is why it's so important to make sure that you only choose a qualified and experienced paving contractor to install your driveway as it will be facing significant issues from both above and below.
Benefits of Concrete Driveways
Concrete lands somewhere in the middle of the scale in terms of cost – it's not the cheapest way to go, but it's also not the most expensive either.
While costs can vary based on a number of factors (including region), the general price range for a basic driveway installation will be somewhere between $4 to $10 per square foot.
As we have mentioned before, there are a number of variables involved in pricing a pavement installation but for the most part, the price range above represents a large percentage of concrete driveway paving jobs in terms of the all-in cost to get it installed.
Not only is this a reasonable and competitive up-front cost, but since concrete is a virtually maintenance-free surface covering, the long-term savings you can realize from choosing this paving material for your driveway can be quite substantial.
2. Long Lifespan
The reason why there's such a large variation in its expected age is because there are several important factors that contribute to the quality and durability of the pavement slab.
Variables such as subgrade quality, frequency and type of maintenance performed, drainage considerations, and weather/climate issues can all play a part in the long-term performance of your surface covering.
We hate to sound like a broken record here, but the quality of the actual installation is going to be one of the biggest factors that determine the lifespan of your driveway.
By getting your concrete driveway sealed every 5 years and by choosing a skilled paving contractor who pays close attention to detail and offers quality workmanship, your pavement stands a much better chance of remaining strong, resilient, and durable over the long haul.
3. Quality Appearance
A concrete driveway can provide plenty of "curb appeal" because it offers a neat, clean, and professional look that will complement your home's exterior.
First impressions do count, and a well-installed concrete driveway can provide a memorable one by adding more aesthetic appeal to your home.
4. Strength and Durability
As mentioned earlier, concrete is one of the strongest and most durable building materials on the planet.
The fact that there are concrete structures from the days of antiquity that are still standing today – many of which are still fully functional – is a testament to the unparalleled strength and durability of concrete.
For example, the Pantheon in Rome is a massive structure that was built in 126 A.D. and yet it still remains the world's largest unsupported concrete dome, comprised of more than 4,500 metric tons of Roman concrete!
Although nowhere near as grandiose as an ancient Roman temple, a driveway constructed of concrete can also provide decades of service life due to the outstanding durability of this highly popular building material.
Regardless of what type of exterior decor or landscaping you have installed around your property, concrete can complement a wide range of tastes and styles.
With their expert advice, you are sure to find a style of pavement that can match and enhance the look of your property.
How is a Concrete Driveway Installed?
It is important to note that properly installing a concrete driveway requires a lot of skill and specialized knowledge. Due to the many variables that are involved in mixing, placing and finishing concrete, it's a job that is best left up to a professional paving contractor.
You have to keep in mind that concrete installation is a very time-sensitive process since the material being installed is transforming from a semi-solid state to a solid state literally by the minute.
Without a proper understanding of the timing and quantities needed to properly mix and place concrete at the peak of its viability, you can end up with a huge mess on your hands. Not to mention that once the concrete is set into place, it's going to be extremely difficult to fix.
For this reason, it's a much better idea to go with a trusted and qualified paving contractor who knows how to expertly prepare, mix, and place the concrete for optimal strength and durability.
That being said, here is a basic overview of the steps that your contractor will take to install your concrete driveway:
1. Preparing the Subgrade
Subgrade refers to the actual ground upon which the pavement will be poured. There are some regions of the country where a contractor can simply pour the mixture right on top of the native soil because the composition of the soil allows for a direct overlay.
Other regions, however, have soil that is rich in clay or other types of minerals that expand when they come into contact with moisture, and this can pose a real problem for a paving installation.
Once the soil begins to expand, it can place tremendous pressure on the underside of the slab, creating all the conditions necessary for cracking to begin.
In fact, this is one of the main reasons why cracking in pavement occurs – if it was laid on top of a subgrade that is subject to soil expansion, it's only going to be a matter of time before the cracks start showing up.
So for those regions of the world where a direct overlay simply isn't possible, an additional layer of material known as a subbase will need to be installed before the area can be paved.
But before anything happens, the subgrade will still need to be leveled off and tightly compacted to ensure optimal stability and support for the subbase and slab that will go on top of it.
This can include removing loose rocks, leaves, tree stumps, and other vegetation that could cause surface irregularities.
Once the subgrade has been properly cleared and compacted, it will be ready for the next step.
2. Setting the Forms
The word "forms" refers to the beams of wood that are used to designate the shape and size of the intended driveway.
Much like the borders of a sandbox, the forms designate the outside edges of each side of the pavement, giving your contractor the much-needed parameters to begin the installation.
3. Installing the Subbase
The subbase is typically a layer of gravel that is laid on top of the subgrade to provide extra support for the soon-to-be-installed pavement. The thicker the subbase, the more weight the concrete slab will be able to handle.
So if the driveway is being designed to hold heavy vehicles (e.g. large trucks, RVs, etc), your paving contractor might recommend installing a thicker subbase.
One huge advantage of installing a subbase is that it can provide what's known as a "capillary break" to keep groundwater from seeping into the slab.
It's much easier for water to creep up into the slab via capillary action (i.e. the ability of liquid to flow into substances without the aid of external forces like gravity), when there's no barrier between it and the slab above it.
With a gravel subbase, however, water will have a much tougher time traveling through that thick layer of crushed rocks in order to get to the bottom of the slab.
The average thickness of a subbase layer will be around 4 inches for a concrete driveway but once again, this can be increased or decreased at the discretion of your paving contractor depending on the specific needs of your project.
4. Placing the Concrete
When your paving contractor "places" the concrete, that basically means that they're pouring the semi-solid mixture into the predetermined area and working it into place as it hardens.
This normally requires a crew of about 5-10 people (depending on the size of the concrete project), and because the consistency of the concrete mix is changing by the minute, precision and attention to detail are a must.
As the wet concrete begins to fill the forms, the paving crew will manipulate the mixture as needed to create a smooth surface that is as level as possible.
In this sense, the word "level" does not refer to being completely flat, as we know that there are many driveways that sit on a slope; it actually refers to having an even surface without dips, bulges, or other surface aberrations.
One of the biggest factors that your paving contractor will pay attention to is drainage. Without adequate drainage, your driveway can experience all kinds of problems due to ponding water or storm-water runoff heading in the wrong direction.
Nobody wants to deal with a garage or home that floods every time it rains due to an improperly graded driveway.
That's why your paving contractor will take great pains to ensure that your concrete driveway – from the subgrade all the way to the surface layer of the pavement – has been adequately graded to allow for optimal drainage.
5. Finishing the Concrete
The finishing process also helps to bring some of the finer aggregate particles to the top of the pavement, while pushing the rougher aggregate particles further into the slab.
This creates a smoother surface, along with achieving a better overall appearance.
One of the most important things that your paving contractor will do during the finishing process is install "control joints", which are basically cracks or grooves that are intentionally saw-cut into the pavement at certain intervals.
Without these control joints put into place, it is highly likely that the slab will crack in some unexpected area due to factors such as shrinkage during the curing phase and/or temperature changes.
This is exactly why they're called control joints – they help the paving contractor "control" where the crack is going to end up!
You have to realize that when it comes to concrete pavement, cracking is pretty much inevitable no matter how well-installed the slab may be.
The concrete has still cracked (which is perfectly normal) but does so within the control joint, allowing for an attractive and pristine appearance of the freshly paved concrete driveway.
The curing process is a must for concrete to achieve its full strength. The exact amount of time it will take to cure will depend on several factors including the slab thickness, outdoor temperature, and the compression strength of the concrete.
Unfortunately, many unskilled contractors can sabotage the future strength and hardening of a pavement installation by not allowing the slab enough time to properly cure.
Once again, this demonstrates why it so important to choose an experienced and trustworthy paving contractor to install your new driveway.
Some people mistakenly believe that the concrete dries out completely during the curing process, but this is slightly inaccurate.
It might surprise you to learn that concrete takes a really long time to fully "dry out" as it undergoes a slow, ever-evolving chemical process that causes the mixture to continually get harder and stronger.
In fact, even 50 years after the installation has taken place, concrete still actually contains a tiny fraction of water within its composition.
This is why, as we mentioned earlier, the Hoover Dam is still undergoing the curing process even though the last sections of concrete for the dam were placed in 1935!
Stamped Concrete: A Versatile Paving Option
Stamped concrete has emerged as one of the most versatile paving options available for all kinds of applications including walkways, driveways, pool decks, and patios. For the uninitiated, stamped concrete is basically poured concrete that has been stamped with some type of decorative pattern or design.
Stamped concrete is oftentimes used to mimic a certain look (e.g., brick, natural stone, etc), giving homeowners the ability to achieve the desired aesthetic without the sometimes-prohibitive costs that can come along with installing the actual materials.
As newer technology for stamped concrete continues to develop, homeowners now have even more options to choose from in terms of design, texture, and colors. Some of the most popular options in use today are natural stone patterns such as fieldstone and slate, although cobblestone and brick definitely run a close second.
Another increasingly popular choice for stamped concrete are various types of seamless textures that do not feature joint lines. This lends itself to a smoother, uninterrupted look that can complement a wide range of outdoor decorating styles.
When installed correctly, stamped concrete is exceptionally durable and highly resistant to cracks, and because it has a textured surface, it offers a level of slip-resistance that is often superior to that of traditional concrete. But without question, one of the stand-out benefits of stamped concrete is its realistic look.
This is achieved by way of specially crafted polyurethane stamping mats that have been molded from the actual brick, stone, or other natural materials that the mats have been designed to imitate.
In some ways, stamped concrete can offer a look that even the real materials can't achieve, as many times weed growth and moss between the joints of the natural materials can detract from their overall appearance.
There are also a number of different methods that your paving contractor can use to achieve color variations that appear very natural, including combining a surface-applied coloring substance with dry-shake pigments to achieve a multi-toned color mixture.
As you can see, there is quite a bit of artistry involved in creating various looks and effects for a stamped concrete surface. It all adds up to a finished product that is much more unique and aesthetically appealing.
Concrete Pavers/Paving Stone Driveways
Concrete pavers – also referred to as paving stones – are an immensely popular choice for both residential and commercial applications. This is due in large part to their outstanding versatility, ease of installation and wide range of colors, textures, and shapes. The primary strength of concrete pavers comes from the fact that they are comprised of interlocking units, which when properly installed can create an exceptionally strong and durable surface.
This concept is nothing new. In fact, the idea of interlocking paving stones can actually be traced back to the days of the Roman Empire. As a testimony to their outstanding durability, many of those ancient Roman roads still exist and are in functional use today, thousands of years after they were built!
Most pavers are made from various sands and crushed stone combined with cement, along with pigments to add color to their appearance. They are extremely dense, which helps to minimize any moisture penetration that could potentially damage the paving stones during freezing and warming cycles.
In addition, the spaces in between the pavers are typically filled with sand, which creates a strong interlocking vertical connection between the pavers. This enables the entire network of stones to work together as a highly durable yet flexible "mat".
The majority of paving stones on the market are produced with beveled edges on the top portion of the stones. This can reduce safety risks or tripping hazards in cases where the stones might not be perfectly flush with one another across an uneven surface. The coarse texture of paving stones allows for better traction and improved slip resistance, which is another nice check mark in the safety column.
Some of the most common applications for concrete pavers include:
- Driveways and walkways
- Patios and pool decks
- Playgrounds, streets, and fountains
Stained Concrete: A World of Possibilities
While standard plain gray concrete is still the most prevalent type of driveway installation, modern technology now offers you an expansive array of decorative concrete options that can create a more fitting and harmonious look to your home's exterior.
Stained concrete is another attractive and economical option for homeowners who are looking to add some visual flare to their driveway. With a typical stained concrete installation, your paving contractor will apply the stains by hand once the concrete sets.
Using stains, your paving contractor can add a variety of bold accents or subtle hints of color that will penetrate deeply into the surface of the pavement, making them fade-resistant and impervious to peeling or flaking.
There are two basic types of stains that are commonly in use today: Acid-based stains and water-based stains.
Acid-based stains produce a chemical reaction with the concrete that creates a rich, unique and beautiful finish, but they are mostly limited to earth tones and other similar colors. Water-based stains, on the other hand, offer a wide variety of visually bold and vibrant colors.
Your paving contractor may also offer additional aesthetic elements such as faux or decorative finishing, stenciling, and/or decorative sawcutting.
Whether you choose stamped or stained concrete (or some combination of both), your paving contractor will help you review the many styles and color options available for your design needs and budgetary requirements.
With their help, you can transform your driveway into an amazing work of art!
Concrete Driveways: Bottom Line
Now that you have a better picture of the incredible scope, versatility and cost-effectiveness that concrete paving offers, it's not surprising why so many residential and commercial customers choose both poured concrete and paving stones for their home improvement and building projects.
As you can see, there are distinct benefits to each of the concrete options covered above. Which one you choose should be based on your individual needs and budget.
No matter which concrete material you decide to go with, your best bet for ensuring a successful driveway investment is to enlist the help of one of our qualified and trusted paving contractors.
With their help, you can create a stunning, one-of-a-kind look for your driveway that will turn heads and set the overall tone for the look, feel, and value of your property.
Concrete Repair Overview
Concrete is one of the most widely used paving materials known to man and even though it is exceptionally strong and remarkably durable, it's not completely immune to natural deterioration or damage over time. To ensure maximum concrete lifespan, it is generally recommended to get your concrete pavement sealed every 5 years after installation.
Not only will this help protect exterior concrete that is exposed to ever-changing weather conditions, but it can also help protect against harsh chemical spills, oil stains, and moisture absorption. A high-quality sealer can even enhance the color of stained or stamped concrete.
Even with proper sealing, it is still very common for paving contractors to be called upon to perform some type of concrete repair, often as a result of structural issues that have been in the works for a long time.
To give you a clearer picture of what we're referring to, below is a list of some of the most common concrete repair problems and what can be done to fix them.
Why Does Concrete Crack?
Bear in mind that concrete is a semi-liquid mixture when it is first placed and it will change in volume once it cures.
Just like a sponge will usually shrink and become smaller when it's dry versus when wet, concrete can be subject to shrinkage once it dries as well. A typical concrete slab will usually shrink to the tune of about one-sixteenth of an inch per 10 feet of pavement.
This is the reason why your paving contractor will intentionally put control joints in the pavement – it allows this natural contraction to take place so that when there is a change in the volume of the concrete, the cracks can follow these pre-set joint lines instead of forming in unsightly places.
When properly installed, concrete is one of the strongest and most durable building materials you'll find, but achieving this type of crack-resistant concrete is not always as easy as it looks.
Here are some of the most common reasons why concrete tends to crack:
* Rapid drying: It's obviously a good thing for your pavement installation to dry out, but it's not so great when it dries too fast as this can make the slab highly susceptible to cracking.
Concrete requires water in order to convert its composition from a semi-liquid state into a hard, solid state and it's up to your paving contractor to know how to properly cure the slab so that it dries effectively. An unskilled paving contractor can easily botch the curing process, allowing the slab to dry too quickly and subsequently making it more vulnerable to cracking.
* Too much water in the mix:
Achieving the maximum strength level for a concrete installation requires a good understanding of how much water should be added to the mix in each phase of the process. Many unskilled paving contractors add too much water to the concrete during the installation, mainly because it makes the concrete a little easier to work with.
Unfortunately, this excess water has a detrimental effect on the overall strength of the concrete. As mentioned earlier, concrete slightly decreases in volume as it dries. So if the mix has a relatively high water content (i.e. it's more "soupy" vs. a thick milkshake), it has a higher potential of experiencing notable shrinkage once this excess water begins to evaporate.
To sum it up, the lower the water-to-cement ratio, the stronger the concrete will be when it dries and vice-versa. Your paving contractor will need to ensure that the right mix ratio is used so that your pavement installation will achieve its maximum strength level.
* Not enough control joints: As mentioned earlier, control joints are put into place by your paving contractor to ensure that the concrete has a place to "stress out", so that it won't crack in unexpected places.
A general rule of thumb that experienced paving contractors abide by is that control joints should be spaced apart no more than 2 to 3 times (in feet) what the thickness of the concrete slab is (in inches). For example, a 4-inch thick slab should have control joints placed approximately 8 to 12 feet apart.
There is a common misconception that if steel-reinforced bars (aka rebar) are used in the installation, the pavement won't crack. While using rebar won't completely prevent cracking, it will definitely help hold the concrete together should cracking occur.
* Concrete is not the proper strength for the job: Ready-mix concrete is available in several different "compressive strength" ratings. These ratings can vary from 2500 psi for residential purposes, to 5000 psi and higher for commercial applications.
Your paving contractor should be well-versed in which compressive strength rating will be the most appropriate for the type of installation being performed.
* Poorly installed subbase: Cracking is often the result of poor installation practices and one of the most prevalent areas where subpar paving contractors miss the mark is during the installation of the subbase.
In order to provide optimal support for the pavement slab, it is a must for the subbase to be tightly compacted with high-quality aggregate before pouring the paving material over it. Unfortunately, some unprofessional contractors will install a subbase that is either too thin, or even use inappropriate subbase materials such as dirt or sand.
Once this looser material is exposed to moisture, it will inevitably fall victim to the expansion and contraction phases from natural freezing and thawing cycles, putting undue pressure on the slab and setting the perfect stage for cracking to occur.
A reputable paving contractor, on the other hand, will only use high-quality aggregate for the subbase so that it can provide the much-needed stability to support the heavy pavement slab.
* Excessive weight: One of the first things that your paving contractor will find out when assessing your pavement project is how much weight the slab is intended to bear. As strong as concrete is, it's not invincible and there will come a point where its load tolerance reaches its limit.
In the same way that pressure from underneath the slab can cause it to crack, pressure from above the slab can produce cracking as well. Variables such as the type, thickness or depth of the concrete, quality of the subbase, and whether or not the material will contain reinforcements such as rebar or fiber mesh can all factor into a pavement's weight tolerance.
Generally speaking, extremely large vehicles such as semi-trucks and RV's that weigh well beyond the typical residential vehicle are most likely to crack a pavement slab due to their excessive weight.
This is especially true for concrete paving structures that are subject to regular load stresses such as driveways, parking lots, and interstate roads. Cracks will typically start on the surface of the pavement, and then work their way down to the bottom over several weeks or months.
If a crack reaches the subgrade of the slab, your paving contractor will more than likely have to completely replace that area of the structure in order to restore it back to its optimal strength. Some cracks can appear shortly after the concrete was poured, while others might take years to emerge.
Either way, the job of your paving contractor is to assess what type of damage has occurred (especially why it occurred), and then come up with an effective game plan to fix the situation. Below is roundup of some of the most common types of concrete cracks, followed by a list of the key reasons why these cracks develop in the first place.
As the name implies, random cracks do not follow any particular pattern but tend to spread out in several different directions. This stands in contrast to other common cracking patterns in pavement such as vertical, transverse, longitudinal, or diagonal cracks.
Random cracks are typically distributed across the surface of the pavement in an uneven fashion and although their depth can vary, they rarely extend below the mid-depth level of the slab.
If moisture happens to seep underneath the concrete, this can cause an expansion of the crack once the moisture freezes. You might also see flaking (i.e. small, thin chips or shards of concrete) in the areas immediately surrounding the crack.
More often than not, these types of cracks are caused by some type of concrete shrinkage (also known as "plastic shrinkage"), especially during the period of time when the slab is hardening or drying after installation. This is particularly true when the surface layer of the pavement is drying too fast in relation to the concrete below it.
Another common reason for random cracks is the settlement of the ground or subgrade upon which the concrete slab was poured.
These cracks are very thin and somewhat "unimpressive" in appearance, but they can run very deep. Hairline cracks often occur as a result of settlement of the concrete during the curing process. Because hairline cracks can run so deep, they can wreak even more havoc once the concrete mixture has fully hardened, often producing major cracks later down the line.
This type of cracking definitely lives up to its colorful name. Also known as "map cracking" or "checking", crazing refers to a network of small, fine, spiderweb-like cracks that primarily affect the surface layer of the pavement.
These cracks typically remain on a shallow level so they won't really have any impact on the structural stability of the pavement, but they can definitely diminish its overall appearance.
One of the most common culprits for crazing is the premature shrinkage of the surface layer, not too long after the pavement has been placed. Other common causes for crazing include insufficient curing or using an overly wet cement mix.
As you can see, poor installation practices can have a big effect on whether a condition like crazing develops in your pavement. This underscores the importance of working with a qualified paving contractor and is what Save On Paving is all about.
These are cone-shaped fragments of aggregate that break out on the surface of the pavement. Pop-outs are typically the result of particularly porous aggregate materials with high absorption rates taking in too much moisture, and then expanding to the point of "popping out" of the concrete slab.
Examples of common materials that are subject to pop-outs include shale, coal, ironstone, and fine-grain limestone. Most of the time, pop-outs will happen within one year of the initial placement and can sometimes be brought on by prolonged wet weather.
While they are unsightly, pop-outs don't really pose a threat to the structural stability of the pavement and other than being a potential eyesore, they generally do not hamper the service life of the slab.
Also known as "offset cracking", these are larger cracks that typically cause the concrete to become uneven on its surface. Settlement cracking is often a symptom of a deeper structural issue, such as the slab being laid over subgrade soil that was of a poor consistency, or lack of compaction of the subbase before the pavement was placed.
Another common cause for settlement cracking is installing the pavement over an uneven surface, or the shifting or settling of the underlying subgrade after the installation has taken place. In addition, it is not uncommon for settlement cracking to occur due to tree roots growing and expanding underneath the concrete.
To remedy this issue, your paving contractor may need to excavate the affected area and restore the subbase to prevent future cracking.
These types of cracks come from soil expansion beneath the pavement and they are the result of the regular freezing and thawing cycles of the soil. Heaving cracks are similar to settlement cracks in appearance and they are typically more prevalent in colder northern climates.
Once warmer weather arrives, the frost heave will obviously settle down a bit, but the main concern to look out for is moisture penetration into the cracks that have already occurred. This moisture could end up seeping into the underlying soil, possibly compounding the problem by the time the next wave of cold weather arrives.
Scaling is another common concrete repair issue. Also known as "pitting", scaling refers to a loss of surface material that almost looks like the top layer has been roughly shaved off, producing small pock marks that expose the aggregate directly beneath the surface layer.
Scaling generally starts as a small, localized patch but it can eventually merge with other small patches to create a larger patch that is hard to overlook. When light scaling is present, the coarse aggregate underneath generally remains hidden but with heavier scaling issues, the aggregate will be clearly exposed making it stick out like a sore thumb.
Scaling almost makes the pavement surface look like it has "scabs" and if light enough, causes little more than a cosmetic problem. However, if left too long it can cause significant structural damage.
When left unaddressed, scaling can lead to deterioration that includes large chunks of concrete separating from the slab itself. Scaling is very common in areas of the country where regular freezing and thawing cycles occur, and is often exacerbated by the use of de-icing salts on the pavement surface.
Sometimes scaling can occur due to delamination, which is basically where too much air or water remains within the concrete after it has been finished. Tiny little pockets of air and water begin to form just beneath the surface, forming "blisters" that sometimes break open to produce scaling.
Causes of Scaling
* Inexperienced contractors often use concrete that contains little to no entrained air. For the uninitiated, air-entrained concrete is a special mix that includes billions of microscopic air pockets that help to relieve pressure within the concrete by giving water a place to expand when it freezes.
* As briefly mentioned earlier, de-icing salts – particularly those that contain chemicals such as ammonium nitrate or ammonium sulfate – can introduce significant chemical trauma to the surface of the pavement which often will result in scaling.
* Subpar finishing procedures can sometimes result in scaling. For example, inexperienced paving contractors will sometimes work bleed water back into the top surface of the pavement slab, which boosts the water-to-cement ratio and thus reduces the strength of the surface layer.
In addition, overworking the surface layer during the finishing process will diminish its air content, making it more vulnerable to scaling during freezing conditions.
* Yet another example of how poor installation practices can reduce the durability of pavement can be seen in the effects of insufficient curing. Shortcutting the curing process will often result in a weak or substandard surface skin, which can be susceptible to scaling when exposed to regular freezing and thawing cycles.
One of the most common preventative measures that can defend against scaling is to refrain from using de-icers during the first winter after the concrete installation has taken place.
A more severe form of scaling is known as spalling, which are surface depressions that run a little deeper than those of scaling. Similar to scaling, spalling is also caused by pressure underneath the surface of the slab.
If steel rebar was used in the installation, it is not uncommon for spalling aberrations to follow a linear path that basically mimics the direction of the rebar. If the rebar begins to rust, this process of corrosion can create pressure as the rust starts to form underneath the surface.
This can push away portions of the pavement, exposing the corroded metal within the pavement slab. Spalling that exposes rusted rebar to air and moisture can accelerate the corrosion process, setting the stage for even faster deterioration of the pavement.
This can be any type of light or dark patch on the concrete and it often results from improper installation practices. Other common causes for discoloration include exposure to chemicals such as oil or other fluids from leaky vehicles.
Motor oil in particular, when not cleaned up quickly, can begin to eat away at the pavement surface which may eventually result in pitting or major chunks of the pavement becoming dislodged.
If you start to notice discoloration on your pavement installation, be sure to address it as soon as possible so that it won't begin spreading across other areas of the slab. It is highly recommended for you to consult with a professional paving contractor regarding this issue, because incorrectly applied cleaning solutions can do more harm than good to your pavement surface.
Dusting, as the name implies, is when a powdery, dust-like material is present on the surface of the slab after it has dried and hardened. Dusting is typically caused by – you guessed it – poor installation practices, where bleed water is worked back into the surface of the slab during the finishing operation.
Inadequate curing is another common cause of dusting. When the pavement slab is not given enough time to properly cure, the surface of the concrete can become soft and chalky. Cold weather installations in particular can become susceptible to dusting, as the concrete will set a little slower in low temperatures.
If relative humidity levels are high, the pavement slab will often be subject to water condensation which can cause dusting if this water is worked back into the surface of the slab via troweling.
This is when hollow bumps emerge on the surface of the pavement. The bumps are typically on the low-profile side and they usually measure about two to three inches in diameter.
As with practically all of the other common pavement problems discussed here, blistering can also be caused by poor installation practices. For example, it is often the result of troweling the surface of the pavement before the underlying mixture has firmed up enough.
Concrete Repair: Bottom Line
If you detected a running theme throughout all of the above concrete repair problems, it would be that improper concrete installation is a make-or-break factor in regards to the long-term quality and durability of your pavement slab.
Unfortunately, many people find this out too late after they've been left with a substandard paving job that was performed by an unskilled or inexperienced paving contractor.
If you're having any pavement repair problems, you've come to the right place. Save On Paving can connect you with highly skilled, experienced, and trusted paving contractors who know how to accomplish your concrete repair job with the proper technique and workmanship.
Contact us today to see how our paving contractors can help you get your concrete installation back in top shape again.
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