What benefits can I get by opting to use a concrete driveway instead of an asphalt driveway?
Begin by considering the cost of the driveway over its lifetime. A good quality concrete driveway will last more than 30 years with little or no maintenance. Asphalt driveways need periodic sealing coats to retard-age related cracking. Even properly constructed residential asphalt driveways will deteriorate more quickly due to environmental influences than due to vehicle traffic. If you consider the cost of surface and crack sealers and the shorter life-span of the asphalt, concrete will cost much less.
How big is a cubic yard?
A cubic yard of concrete measures three feet by three feet by three feet, or 27 cubic feet. It will weigh about 4000 pounds. It will cover an area of 81 square feet when placed four inches thick. A concrete mixer truck can deliver up to ten cubic yards per load.
What type of concrete mix should be used?
The concrete should be at least 4000 psi, with 6% air-entrainment. It's also a good idea to use a water-reducing admixture to lower the concrete's water-cement ratio below .45. Most high-performance concrete will include fly ash and water-reducing admixtures to provide long-term strength gain and initial workability without the addition of water. High-performance concrete mixes can be designed for easy placement, so your contractor isn't saddled with a hard-to-handle concrete mix.
How thick should a concrete driveway be?
A minimum of 4 inches is recommended. Keep in mind that the 2 x 4's often used to form driveways are only 3 ½ inches wide, so the ground inside the 2 x 4 forming needs to be removed at least ½ inch below the bottom of the form. Thickness is the major factor (even more than the strength of the concrete) in determining the driveway's structural capacity. Increasing your driveway's thickness from 4 inches to 5 inches will add 20% to your concrete cost, but the additional inch of concrete will add almost 50% to load-carrying capacity of your driveway.
What Type of Finish Should I use?
The two main types used are hard-troweled and broom finish. Trowel finishes are usually used indoors where a smooth, hard and flat surface is required. Broom finishes are appropriate for exterior slabs such as sidewalks, offering durability and a slip resistant surface. Decorative finishes are also available, including: Patterned, Colored and Exposed Aggregate.
What provision can be made to avoid cracks?
There are many reasons why concrete cracks. Cracks rarely affect structural integrity. The majority of concrete cracks usually occur due to improper design and construction practices, such as: omission of isolation & control joints, improper jointing practices, improper sub grade preparation, the use of high slump (very wet) concrete or addition of water on the job, improper finishing and inadequate or no curing. Concrete "shrinks" slightly as it hardens, therefore; proper spacing of joints is most important.
Should there be joints in a concrete driveway?
Install control joints at a spacing of no more than 10' x 10'. Spacing joints at wider intervals invites random cracking. While such cracks are generally not a structural problem, and will not reduce the service life of the driveway, they are unsightly. Also avoid joint patterns that produce rectangular or triangular sections. Lay out your joints to form square sections. If in doubt, make the sections smaller, not larger.
Is it necessary to seal a concrete driveway?
Periodically sealing a concrete driveway will protect it from water or chemical absorption. This will make it much easier to clean accidental spills and will also help prevent the occurrence of surface defects. Always follow manufacturers' recommendations for sealing concrete.
When can I drive on my new driveway?
Foot traffic is allowed after one day and vehicle traffic after five days.
What are some appearance types for concrete?
Leveling and finishing of the surface and edges is accomplished with trowels, while the concrete is wet. The surface of the wet concrete may be "Broom Finished" in a uniform procedure, which creates a slightly rough look. The broom finish is important for exterior slabs in order to prevent the concrete from being slippery when wet.
During the finishing, control joints are troweled into the wet concrete to aid in controlling short and long term cracking.
A base color is selected and added into the wet concrete typically after it arrives in a truck to the work site. This manual addition of the color (liquid or powder) selected is controlled based on the volume of concrete delivered.
Leveling and finishing of the surface and edges is accomplished with trowels, while the concrete is wet. As with ordinary concrete, the surface of the wet concrete may be "Broom Finished" in a uniform procedure, which creates a slightly rough look.
Power washing to remove the color residue dust and then sealing should take place within a short period of time before any surface staining occurs. Sealing will create a beautiful and long lasting look of the vibrant color selected.
"Colored" is one step above Ordinary concrete
Exposed Aggregate Concrete;
An aggregate (rock) color and size is selected to be added to the concrete mix at the batching facility before being delivered to the work site. All concrete includes a basic limestone (white) or river rock (generally brown), but in exposed aggregate a multi-color rock is used. Exposed implies the many colored rocks will be slightly raised (exposed) at the surface when completed, creating a slightly rough slip resistant condition.
Leveling and some finishing of the surface and edges is accomplished with trowels, while the concrete is wet. (as in ordinary concrete) The surface is level and almost smooth at this time.
During the finishing, expansion joints are troweled into the wet concrete to aid in controlling short and long term cracking.
While the concrete is wet a chemical is sprayed on the surface that keeps the concrete around the surface rocks from becoming solid over the initial 24 hrs +/- curing period. The entire surface is immediately covered with a layer of plastic sheeting. This creates a moister than normal condition for the near surface overnight.
The plastic sheeting is removed the next day to allow power washing of the surface that was kept chemically moistened overnight. The power spraying removes a thin layer of pasty concrete around the surface rocks. The exposed effect has now been created with the near surface colored rock being exposed. (Generally raised 1/16-1/8 inch)
The last step necessary (likely the 2nd or 3rd day) in creating a beautiful and long lasting look is to apply a seal to the surface.
"Exposed Aggregate" is a couple of steps above Ordinary concrete
Involves many additional steps to create the contrasting selected colors and patterns;
A base color is selected and added into the wet concrete typically after it arrives in a truck to the work site. This manual addition of the color (liquid or powder) selected is controlled based on the volume of concrete delivered. After through mixing time, the colored mix is placed, leveled and lightly troweled, just as ordinary concrete. (per gallon, lighter shade colors are generally cheaper than darker)
A secondary color selected (powder or liquid form) is broadcast across the wet concrete. This colored powder assists in preventing the rubber mat sticking to the concrete and the concrete to the mat and creates the final contrasting appearance. While the concrete is wet, now with the contained color and surface color, the stamping process begins. The pattern type selected is actually large rubber mats that are placed like a jigsaw puzzle. The rubber mat is hand tamped at each temporary location to create the pattern. Each mat is lifted, moved, and then placed again with the pattern continuing across the desired area of concrete.
Expansion joints are cut into the concrete the next day to aid in controlling short and long term cracking.
Power washing is also done the next day to remove the powder residue remaining from the secondary color. At this time the contrast between the base color and secondary color becomes apparent.
The last step necessary (likely the 3rd day) in creating a beautiful and long lasting look is to apply a seal to the surface.
"Stamped" concrete may be compared to the "Cadillac" version of ordinary concrete.
All of the fore mentioned "types" may have their own slight variables and are applicable to outside or inside concrete.
How long will my project take?
A typical driveway replacement or concrete project takes 1 to 2 days. Although occasionally larger projects take longer.
Is a deposit required before work can begin?
No, Here at North Georgia Concrete, we don’t require any upfront deposits. Payment is due upon completion of the project and clean-up is complete.