Frequently Asked Questions

General Questions | Paving Questions
Patching and Repair Questions | Sealcoating Questions
Crack Repair Questions | Concrete Repair Services
Cement Stabilization Questions | Glossary for Asphalt Paving Terminology

Concrete Repair and Services


General Questions

What sort of maintenance is required to prolong the life of your parking lot?

It is recommended that an asphalt parking lot be maintained regularly to prevent surface aggregate from deteriorating, to slow the formation of stress cracks and also to maintain the aesthetics of your property. We recommend annual preventative maintenance as in crack-filling when new cracks occur. Sealer should be applied to your lot at least every two years. Corrective maintenance is necessary less often when excessive rutting and cracking occur or other structurally failed areas develop. This type of maintenance includes patching, peel and pave, mill and overlay or a complete resurfacing.

Do you provide free estimates?

Customer satisfaction is our number one goal. To ensure your project needs are fully understood, we will provide you with a detailed estimate; free of charge.

Employee Screening?

Raleigh Paving has a substance free workplace policy. Employees are required to pass drug and alcohol testing. We also runs criminal and background checks for every new employee.

Safety record?

Our Experience Modification Rate (EMR) has consistently been below 0.90. We pride ourselves on our safety record.

What kind of warranty is provided?

An industry standard, one year warranty for labor and material is provided on all projects. We stand behind our work to meet the satisfaction of our clients.

Residential Driveways

We are a commercial / industrial contractor and we generally do not do residential work unless it is on a commercial level such as HOA’s, apartment complexes, community associations.

Recycling?

We do all kinds of recycling including cold milling, pulverization and concrete stabilization. Any asphalt removed from a job is returned to a plant for using in future mix designs. North Carolina allows sometimes up to 40% recycled asphalt product in their mix designs.

Will my business be shut down during construction?

Project phasing, maintaining safe conditions and keeping businesses operating is one of the areas that distinguishes good contractors from bad contractors. We minimize your impact through proper planning and well marked access and control of work zones.

How can you tell a good contractor from a bad contractor?

Going with a company that has a good reputation is critical. Ask for references and call the local quarries.

How do I get a fair estimate?

Get a spec from a reputable contractor and get other contractors to bid on the same spec. This is usually referred to as the “apples to apples” approach. This eliminates confusion and forces contractors to bid fairly.

Paving

How long will my new asphalt surface last?

Under normal conditions asphalt pavement should last about 10 – 20 years. Pavement life can vary greatly depending on climate, base conditions, amount and type of traffic and pavement maintenance.

What is the minimum temperature for paving?

50 degrees and rising or as required by the project specifications. There are other mitigating factors affecting the final product. This includes weather and material type.

What is the asphalt index?

The volatility in cost for oil and oil related products is well known.Thus, the asphalt index was created to provide a benchmark for material pricing on any project at the time of quotation and is used to calculate an adjustment in the cost for materials at the time of construction. The index is a third party calculation based on the average posted price of the liquid asphalt and is typically generated on a monthly basis by the Department of Transportation (DOT) in the state of which the project resides. The asphalt index provides equal benefit for both the consumer and contractor by eliminating material cost speculation when the contractor quotes a project. Otherwise, the material supplier and contractor may inflate their pricing respectively to cover the unknown cost inflation (or deflation) for materials when quoting projects scheduled to be completed in the more distant future. We are all aware of the volatility of the crude-oil market over the last few years. So how does this affect the price of asphalt. . Asphalt is processed from crude oil into different grades of asphalt cement (AC). AC is the binder holding aggregate (Stone) and Sand together in a mix design producing hot mix asphalt (HMA). In addition, most blacktop plants operate off of fuel oil to run the plant and mixing drum. Thus the price of crude oil affects the price of asphalt. The price of AC is dictated by refineries and published once a month. The asphalt index was created to provide a benchmark for material pricing on any project at the time of quotation and is used to adjust the cost for materials at the time of construction. The index is a third party calculation based on the average posted price of the liquid asphalt and is typically generated on a monthly basis by the Department of Transportation (DOT) in the state of which the project resides. Reputable contractors base their bids on the asphalt index in order to protect themselves from cost increases associated with the volatility of the price of oil. It is not uncommon for a project to be bid in January, a customer waits until August to award the project and by September the cost of asphalt has changed $8.00 per ton. The potential cost adjustment should be shared reflected in the final pricing at the time of construction.

How soon can I use my newly paved surface?

Generally stay off until the next day or until the surface temperature reaches the ambient air temperature.

Blemishing on newly paved asphalt?

Power steering will blemish newly paved asphalt due to the pliability of the asphalt until it has cured. These are only surface blemishes and do not affect the structural integrity. The blemishes will “work in” with time.

What is the difference between asphalt paving and asphalt paving sealer?

If you already know the difference you would probably be surprised how often we get this question. Asphalt paving is really the process of installing asphalt (blacktop) on some sort of surface. Usually the asphalt surface can be measured in inches and the number of courses. It is preferably laid on compacted stone or an old asphalt surface however there are applications which allow it to be laid on other types of surfaces such as dirt, clean stone or concrete. Generally the thickness of the surface depends on the application and the process of determining that thickness can sometimes become very involved. Knowing the type of soil, the thickness of the stone base and the end users application will all help in determining the thickness of the structural system that needs to be put in place.

Asphalt pavement sealer is a surface coating that is applied over the asphalt surface to beautify and protect existing asphalt. It is associated with the process of “asphalt sealcoating” which is usually applied every few years along with pavement marking and line striping. Asphalt sealcoating through asphalt pavement sealer will significantly increase the life of a parking lot by reducing the effects of oxidation and water on the surface of the parking lot. Contrary to what some may lead you to believe, pavement sealer will not reverse any effects of aging that have already occurred. Any cracking in the asphalt surface due to age or insufficient base must be corrected with a structural repair. Crack-filling can help the situation to some degree but should only be seen as a minor corrective measure that will only have limited success.

What is Stamped Asphalt and is it as good as paver blocks?

Stamped asphalt was developed as an inexpensive alternative to the labor intensive installation of paver blocks. There are a few notable differences. First since paver blocks are made of concrete, they are generally colored through the entire block. Stamped asphalt is normally colored by adding a colored surface coating after paving and stamping. In terms of long term wear, concrete paver blocks will hold their color much longer. Stamped asphalt however can be coated again and again. To some this is a benefit and to others this is a con to going with stamped asphalt. We think of it as the difference between vinyl siding (concrete block) and hardy plank. Hardy plank is paintable which is generally considered a benefit. Second, stamped asphalt is generally not as thick as concrete paver blocks which helps it in terms of cost in a normal residential type application. Stamped asphalt however can be as thick as necessary in order to adapt to the application which makes it useful in many commercial installations.

What is blacktop paving?

The word “blacktop” is interchangeable with the word asphalt. Thus asphalt paving and blacktop paving are the same processes.

Can you pave over concrete?

Yes, it is possible to pave over concrete, however reflective cracking may occur as a result. Generally reflective cracking will occur along all the construction joints in the concrete or where the concrete has already cracked.  This is due to expansion or contraction of the the old concrete surface which is generally focused at the joints. Asphalt expansion and contraction is generally focused on the seams.

What are the major contributors to pavement deterioration?

The deterioration of your pavement surface may occur due to several reasons. The main cause is inadequate thickness of your pavement surface. Other factors include lack of maintenance, oil and gasoline spots from automobiles, or a weak and unstable subbase.

Why should I choose asphalt paving over other methods?

Asphalt is a petroleum-based product used for driveways, roads, cart/walking paths and any project that requires a smooth surface for foot traffic or motorized vehicles. Asphalt is flexible and gives during the harsh weather conditions experienced in our area. It is easily and inexpensively maintained and is aesthetically pleasing.

Patching and Repair

When is the best time to perform patchwork?

The best time to perform patchwork is during the spring and summer months as to allow the asphalt to cure over the winter and be ready for sealer the following year.

What causes potholes to form?

Possible causes of potholes include asphalt that was too thin, base failure under heavy loads or poor drainage that weakens the subgrade and base. Poor quality (segregation in the asphalt, poor compaction, or asphalt that was burnt or did not have enough oil mixed into it) may be a contributing factor.

What are the different kinds of patch repairs?

There are two main types of patch repairs procedures that will provide a suitable fix to most asphalt related issues, full-depth patching (peel and pave) and surface patching. Full-depth patching involves the removal of the entire layer of pavement surface down to or including the subbase, depending on the condition of the stone base. New subbase is then installed, a tack coat is applied and new asphalt pavement is backfilled into the patch area. Surface patching is a more temporary fix and should only be considered for a surface that is in relatively good condition. This process does not involve the excavation of the existing surface or subbase. The asphalt is simply layered over the existing surface and feathered to match the in-place grade. In some cases, a rebate is milled into the surface, which eliminates the need to feather-edge the patch.

Sealcoating

What are the benefits to parking lot repair through asphalt seal coating?

There are many benefits to applying a seal coat to your asphalt surface. First and foremost, this type of parking lot maintenance is a cost effective option that will increase the life span of your property. Also, pavement sealing will prevent water penetration to your subgrade and slow the effects of oxidation. It also makes your parking lot more flexible and resistant to gas and oil spills. Lastly, it will beautify your property by giving the effect of a brand new parking lot.

What is the difference between asphalt sealer and pavement resurfacing?

The seal coating process is a preventative parking lot maintenance process that is sprayed onto your lot in a liquid form after applying asphalt crack filler. Resurfacing is the actual process of applying a whole new layer of asphalt pavement over your old surface for a more complete parking lot repair.

Does the Asphalt Sealer fill in the pavement cracks?

No, sealer will not fill in a pavement crack completely. The recommended method to asphalt crack repair is to apply a hot, rubberized asphalt crack filler product into the crack itself. This is the only way to solve your problem as it will slow the formation of new cracks. Some lots, due to a lack of parking lot maintenance, have deteriorated beyond the point of asphalt crack repair as a beneficial alternative. In these cases, your parking lot will need patch work and/or resurfacing.

How long should I wait before driving on a newly sealed surface?

The recommended wait time to allow traffic back onto your lot after asphalt crack filling and pavement sealing is 24 hours. This allows enough time for the asphalt sealer product to cure and will help prevent tracking and will also reduce power steering marks from appearing after the parking lot repair.

Should a newly paved lot be seal coated right away?

No, it is recommended that a newly paved lot be left to cure for at least one year before the first asphalt seal coat is applied.

When is the best time for a parking lot to be sealed?

The best time for parking lot maintenance though asphalt crack filling and sealing is during the months of May through September when the temperature is at least 50 degrees Fahrenheit.

Crack Repair

Why should I fill in the cracks that have developed in my parking lot with asphalt crack filler?

Asphalt crack repair should be implemented for cracks in your parking lot that are at least a quarter inch thick should be filled in with crack filler as soon as possible to prevent the further growth of that crack and also to prevent water from seeping under your asphalt surface into the subgrade.

Concrete Repair and Services

What sort of concrete services do you provide?

We specialize in curbs, curb repair and flatwork, no job is too big or too small. If we can’t do it with our own forces we know the concrete repair contractors who can and we will be with them every step of the way to assure you that it will meet our high standards and the intent of the plans.

Is there a difference between cement and concrete?

Yes, there is a difference. Cement, or portland cement, is a finely ground powder made from limestone and other raw materials. The materials are blended together and fired in a kiln at extreme temperatures. The resulting stone sized pieces, called clinker, are then ground into a fine powder that we call portland cement. Portland cement is the active ingredient in concrete. Concrete is the product used in buildings, bridges, road paving, sidewalks, patios, etc. Concrete is a mixture of portland cement, water, aggregate (sand and stone), and miscellaneous chemical admixtures. Concrete is mixed at a concrete plant facility and delivered to customers in revolving drum truck mixers, also referred to as concrete trucks or mixer trucks. Concrete is sometimes generically referred to as ready-mix because it is ready to use or already mixed upon arrival at the project location and ready to be put to use for whatever concrete services are necessary.

Can concrete be placed in extremely hot or cold weather?

Concrete services can be performed at various temperatures if precautionary measures are taken. In extremely cold weather, concrete should not be allowed to freeze until it has gained sufficient strength to withstand the damaging effects of freezing. Concrete will lose its workability and set up considerably faster in hot weather.

What causes concrete to crack?

There are different types of concrete cracks. The most common of these is related to the natural shrinkage of concrete as it cures and dries. Shrinkage concrete cracking can be controlled or hidden by following proper jointing techniques. Different factors and conditions can contribute to each type of concrete cracks. It is important to understand these potential causes and take appropriate action to prevent cracking and the subsequent need concrete crack filler or concrete crack repair.

Why does some concrete develop surface deterioration?

Concrete surface deterioration is usually referred to as scaling. Scaling is a local flaking or peeling of the finished, hardened concrete surface, resulting primarily from multiple freeze-thaw cycles. The condition can be aggravated by the presence of de-icing materials such as salt. Any product that is intended to melt ice and snow can contribute to concrete scaling. Even products labeled Safe for Concrete can contribute to scaling. The probability that scaling may occur can be reduced or eliminated by using a durable concrete mix and following recommended concrete placing, finishing and curing/sealing practices performed by an experienced concrete contractor.

What causes discoloration of concrete?

There are different types and causes of concrete discoloration. Dark, shadowy areas may appear if the fresh concrete was placed over alternating wet and dry areas of the subgrade. Darker areas are typically located where the subgrade was too wet or actually muddy. Temporarily covering concrete with poly sheeting or construction blankets can also cause the hardened concrete to be darker in appearance. Another possible cause of dark, mottled areas is the uneven application of curing/sealing products. Curing/sealing products should be applied as uniformly as possible with a nozzle that will produce a fine spray or mist. There can also be differences in coloration between concrete slabs placed on different days. This is usually due to slight variations in temperature and weather conditions from day to day.

How soon can new concrete be put into use?

During periods of moderate to warm weather, new concrete could be opened for pedestrian traffic in twelve to twenty-four hours, or when the surface becomes scuff resistant. A general guideline is that new concrete should not be opened for vehicular traffic for a minimum of seven days. This seven-day period can be significantly reduced by using a faster setting, stronger concrete mix. Please note that concrete gains strength more slowly in colder weather so more time may be needed before putting your new concrete into use.

Cement Stabilization

What does FDR stand for?

FDR stands for full depth reclamation. This is a process that we often use on tennis courts or existing roadways. When a soft subgrade is indicated by conditions on the surface, FDR is done by stabilizing the stone base on top. This creates a concrete bridge over soft subgrade formed by the cement and the stone matrix.

Is stabilization guaranteed to work?

Unfortunately nothing in the world of construction is guaranteed to work when budget constraints control the specifications. It will definitely improve any soft subgrade condition. Anyone knowledgeable in the cement stabilization business will generally know the limits to stabilization. Some conditions may need either additional treatment or other types of remediation. In general though, from our experience, stabilization is more effective than any other solution today.

Is it messy to work with?

Actually yes and no. It is dry cement so there is a lot of dust until its ground in. Cars should generally stay away. We usually wear masks when placing it as it gets in the lungs when you are close to it and it makes you feel bad for a few days. We usually keep the time that the cement is being placed to a contained period to limit the dust. We have had less issues with the cement than we do with asphalt tack.

Glossary for Asphalt Paving Terminology

Asphalt(Asphalt Cement): A dark brown to black cementitious material in which the predominating constituents are bitumens, which occur in nature or are obtained in petroleum processing. Asphalt is a constituent in varying proportions of most crude petroleum and used for paving, roofing, industrial and other special purposes.

Aggregates: Usually various sized stones, crushed rock, gravel, etc. that make up approximately 92-96% of the asphalt mixture. (Asphalt Cement makes up the other 4-8 %.)

Asphalt Base: Asphalt mix where the largest stone used is no larger than 3/4 of an inch (typically #57 gradation). Base mixes are usually laid over a stone base at a minimum depth of 2 inches compacted.

Asphalt Binder: The asphalt layer between the base layer of rock or other aggregate and the driving surface layer. The asphalt binder layer is usually made up of coarser materials and is usually thicker than the surface layer. The binder layer can be used as either a first layer or a driving surface, but its use is actually fairly limited. The vast majority of jobs call for a stone base layer, an asphalt base layer, and then a surface layer.

Asphalt Leveling Course: A course of hot mix asphalt of variable thickness used to eliminate irregularities in the contours of an existing surface prior to placing the subsequent course.

Coal Tar: A by-product of coke ovens in the steel production industry. Refined coal tar has been used as a base for asphalt pavement sealers since 1938. It has become more expensive in recent years due to the shift in steel production to foreign countries.

Compaction: Compressing a given volume of material into a lesser volume. A compacted subgrade and base is essential.

Crusher-run: The total unscreened product of a stone crusher.

Density(thickness or compactness): Technically, density refers to the weight of a material at a specific volume (unit weight). A specific density of asphalt is achieved my mechanically compacting (rolling) the hot material after it has been placed by the paving equipment. To most consumers of asphalt, it means the compaction of the material versus a theoretical value that is usually derived in a laboratory.

Emulsion: Mechanically produced combination of ingredients, which do not normally mix. For example, asphalt emulsions are made by a procedure, which mechanically mills the warm asphalt into minute globules, dispersing them in water, and adding a small amount of an emulsifying agent.

Finished Grade: The final grade created as part of the project.

Full-depth Asphalt Pavement: The term full-depth certifies that the pavement is one in which asphalt mixtures are employed for all courses above the subgrade or improved subgrade. A full-depth asphalt pavement is placed directly on the prepared subgrade.

Geotextiles: Geotextile is the technical name for fabric like materials used in the paving process. Geotextiles are manufactured for specific uses and performance characteristics. Some uses include stabilization of base material to prevent migration into sub-grades, retarding of reflective cracking in asphalt overlays, and serving as a moisture barrier between pavement layers.

Grade-Slope: The degree to which a paved surface is angled to aid in the drainage of water. The act of leveling or sloping the subgrade or base layer before paving.

Heat Lance: Device using a combination of propane and compressed air ignited in a specially designed chamber to produce an extremely hot high-velocity stream of air. Used to remove debris and vegetation from pavement cracks prior to sealing. It also warms and dries the crack to better accept the sealant. When properly used federal research has determined this to be a most effective preparation method (SHRP H-106 Data). Although more expensive initially the combination of routing and heat lance preparation can provide 10 times the life of conventional crack sealing methods.

H.M.A.C: Hot Mix Asphalt Concrete. Abbreviation of the proper name for what is commonly referred to as “asphalt”, “hot-mix”, “blacktop” etc. This term should always be used in specifying asphalt pavement work to avoid any confusion or misinterpretation of the material desired. H.M.A.C. is produced in many different grades from coarse base mixes to specialized mixes for surfacing and repair. In most instances the grades are specified according to state department of transportation guidelines.

Joints: An asphalt joint is the area where two different “pulls” of asphalt meet. This area is usually highly visible after the paving operation and is sometimes referred to as a “seam.”

Lane Joint Cracks: longitudinal separations along the seems between two paving lanes.

Lift: A layer or course of paving material applied to a base or a previous layer. Polished aggregate: aggregate particles in a pavement surface that have been worn smooth by traffic.

Reflection Cracks: Cracks in asphalt overlays that reflect the crack pattern in the pavement structure below it.

Seal Coating: Application of a sealant (usually coal-tar emulsion or asphalt emulsion type) to preserve, protect, and beautify asphalt pavements. Generally used on low traffic streets or off-street locations.

Stone Base: The layer in the pavement system below the asphalt binder and driving surface. The base usually consists of crushed stones of varying sizes and gradations.

Subbase The course in the asphalt pavement structure immediately below the base course. If the subgrade soil has adequate support, it may serve as the subbase.

Subgrade: The soil prepared and compacted to support a structure, slab or pavement system.

What is right for your lot?

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