What You Need to Know About Concrete Driveways
February 13, 2023

Categories | Ready-Mix

What You Need to Know About Concrete Driveways

Concrete is a trusted paving solution with an extended service life of 30 years. Not only are concrete driveways and walkways reliable, but they can also elevate your home's curb appeal.

If you're considering installing a concrete driveway, use this frequently asked questions guide to understand industry terminology and basic maintenance. 

Frequently Asked Questions About Concrete Driveways

1. What type of concrete mix should be used?
Consult with a Sales Representative at County Materials or your contractor to determine which concrete mix is best suited for your project.

2. What does Portland cement mean?
Portland cement is an industry term, defined by the American Society for Testing and Materials (ASTM) C 150, that refers to the type of cement used in most concrete.

3. What does cementitious mean?
This term describes the materials used to bond the aggregates in concrete together. Portland cement, blended cement, hydraulic cement, fly ash, slag cement, silica fume, and other supplementary materials combine to form cementitious material.

4. What are supplementary cementitious materials?
Also known as mineral admixtures, supplementary cementitious materials enhance the properties of hardened concrete through hydraulic or pozzolanic activity. Common materials include fly ash and ground granulated blast furnace slag.

5. What is the water/cementitious (w/cm) ratio?
Water/cementitious ratios indicate durability and strength. They are expressed by the pounds of free water not absorbed by the aggregate divided by the pounds of cementitious materials in the mix.

6. What is psi?
Psi, or pounds per square inch, is a unit of measurement that indicates force per unit area and is used to measure the compressive strength of concrete. In Florida, common practice for residential driveways is 3000 psi.

7. How thick should a concrete driveway be?
Thickness is a significant factor in determining a driveway's structural capability. A standard driveway intended to support cars and light trucks will require a minimum of 4 inches, whereas a slab supporting oversized loads should be 5 inches or more.

8. What kind of base and subgrade preparation needs to be done?
Base refers to the material underneath the concrete. It typically comprises compacted gravel or crushed stone to allow for adequate drainage. Before placing base materials, remove organic material and soft pockets of subgrade to protect the structural integrity of the driveway. The base and subgrade should be uniform in firmness, grade, and dampness and must slope away from structures, allowing for proper drainage, with a minimum slope of ¼ inch per foot.

9. Should there be reinforcement in my driveway?
Fiber reinforcement is often used to contain cracks. Ask your contractor if your project requires reinforcement.

10. What should the surface texture be on the driveway?
A broom finish for exterior concrete is ideal, providing a slip-resistant surface. Concrete can also be stamped to achieve a custom appearance. 

11.  What causes concrete to crack?
The leading culprit of cracking is improper design and construction practices; however, proper joint spacing is also a contributing factor.

12. Should there be joints in a concrete driveway?
Install control joints at a spacing of 10'x10' and to a depth of no less than 1/3 the thickness of the slab. Spacing joints that exceed these parameters are more prone to random cracking. These cracks impact the driveway's aesthetics more so than its structural integrity.

13. Why must driveways be cured?
Curing is essential to the construction process, as concrete strengthens with time. Allow freshly poured concrete to cure for at least one week—inadequate cure time results in surface strength reductions of up to 50 percent.

14. Is it necessary to seal a concrete driveway?
Periodically sealing a concrete driveway will protect it from water and chemical absorption, making it easier to clean accidental spills and prevent surface defects. For more information, contact County Materials.

15. How important is the role of the concrete contractor?
A contractor's involvement plays a significant role in the outcome of a project. The contractor is responsible for placing, finishing, curing, and sealing the driveway. Working with a reputable contractor is the best way to achieve your desired results.

Use County Materials' Ready-Mix for your next project by contacting our Customer Service Team at (352) 343-8488, option 3.