To ensure that your concrete driveway will look good for many years to come, there are important steps Blue Valley Construction will follow during installation. How well your driveway looks and performs long-term is largely related to the quality of workmanship and materials that go into it. To help ensure a problem-free driveway, we use the following process for proper construction.A properly prepared subgrade:
Uniformity, in both soil composition and compaction, is the key to a good subgrade-one that will provide adequate support, we ensure an even slab thickness, and prevent slab settlement and structural cracking. Soft spots should be removed and replaced with good material, such as gravel or crushed rock. Blue Valley Construction will use ½” to ¾” clean aggregate as a subgrade.
Use a high-performance, air-entrained concrete mix:
A high-performance concrete mix may cost a bit more per square foot initially than a basic mix, but in the long run it could save you the expense and headaches of repairing cracks and other problems caused by an inadequate mix design. Keep in mind that your driveway will be subject to vehicle traffic, freeze/thaw conditions (in most climates), and possibly deicing chemicals. You'll need a durable, low-permeability mix to withstand these conditions. A compressive strength of at least 4000 psi is used.
Correctly placed joints: To help prevent random cracking, control joints we place at a maximum spacing of 12 feet for a 4-inch-thick driveway slab. While random cracks are generally not a structural problem and will not reduce the service life of the driveway, they can be an eyesore. Also avoid joint patterns that produce triangular sections. The depth of control joints is also critical. Our crew will hand tool or sawcut them to a depth equaling one-fourth the slab thickness (or 1 inch for a 4-inch slab).
Reinforcement: Using steel reinforcement will provide additional structural capacity for your driveway and is especially important if the slab will be exposed to heavy traffic. Reinforcement won't prevent cracks, but it will help hold them together if they do occur. Reinforcement will be (#4) steel rebar placed in a grid pattern with a minimum spacing between bars of approximately 36 inches. Synthetic fibers have also proven to be beneficial in driveways as a way to reduce shrinkage cracks. Fibers will not provide structural reinforcement.
Placing concrete at the proper thickness: Thickness is the major factor (even more than the strength of the concrete) in determining a driveway's structural capacity. We place concrete at a minimum thickness of 4 inches. Increasing the thickness from 4 inches to 5 inches will add approximately 20% to your concrete cost, but will also boost your driveway's load-carrying capacity nearly 50%.
Proper finishing: The biggest mistakes that occur during the finishing of concrete driveways are overworking the surface and performing finishing operations while bleedwater is present.Finishing is generally a three-step process. Blue Valley Construction will:
- Level or strike off the concrete with a screed to achieve a uniform surgace.
- Float the concrete with a wood or magnesium bullfloat before bleedwater accumulates.
- Apply a simple broom finish to improve traction- unless plans call for stamping the driveway or applying another type of decorative textured finish.
Proper drainage: To eliminate standing water on your driveway, it should be sloped toward the street and away from existing structures (such as your house and garage) a minimum of 1/8 inch per foot, If proper drainage is prevented because the concrete slab is wedged between two structures, you may need to install a drain that will collect the water at a low point in the concrete and divert it away.
Proper curing techniques: Cure the concrete as soon as finishing is completed. Curing of the concrete is the final step of the process, and one of the most important. Unfortunately, it's also one of the most neglected.