The Basic Ingredients
Concrete MixingAll concrete consists of four basic ingredients; Portland cement, sand, gravel or crushed rock, and water. The intended purpose of the concrete will dictate the proportions of these ingredients. A reliable concrete contractor or ready mix concrete producer will be knowledgeable about which mixing ratio will be proper for any given project.
Almost every ready mixed concrete producer offers a warranty that concrete will cure to a specific density and hardness. Be sure to get a guarantee in writing in the event of a faulty batch requiring removal and re-pouring; provided at the producer's expense.
Which Purchase Option is Best for Me?
Cost is another important factor for homeowners planning a project involving concrete construction; including concrete flooring, a concrete driveway, or a concrete patio.
Skyrocketing concrete prices have necessitated many homeowners to consider handling concrete pouring for large-scale projects themselves. Concrete for any concrete masonry project can be purchased in one of several ways:
- Premixed bags of dry concrete mix - just add water according to instructions on the bag. For large projects such as a concrete floor, this may be the most expensive way to purchase concrete. However, for small projects such as setting fence posts, this may be the most economical means.
- Delivered ready mix concrete - a good option for large projects. Brought right to the job site, wet and ready to pour in a cement mixer truck. Expect to pay a delivery charge as well as a premium price per cubic yard of product. Shop competitors for the best price and warranty.
- Haul-it-yourself ready mix concrete - an option offered by some ready mix producers. Can be a good money-saving option. However, you will need the means to haul it; trailer mount mixers are available for rental. Shop competitors for rental and concrete prices.
- Portland cement - purchased in bulk to mix with the other ingredients at the job site. This may be the most cost-effective way for a large project, but keep in mind you will need a concrete mixer. You will also need to know how to mix Portland cement using the proper ratio of other ingredients required.
Concrete Mixing Guidelines
When mixing your own concrete, make sure the water is clean. Neither acid nor alkaline, and free from any oil or sulfates. Sand and gravel should also be clean and free of any foreign matter. Remember to adjust water amounts for using wet or dry sand.
The amount of Portland cement in the mixture will determine the strength; usually at a cure time of 28 days to measure strength in psi (pounds per square inch). While most concrete is a minimum of 3000 psi strength, some may run as high as 14,500 psi for specialty applications. Some applications may require reinforced concrete that
incorporates steel mesh or re-bar set in the forms before pouring.
A basic guideline is the rule of 6:
- At least 6 bags of Portland cement per cubic yard.
- No more than 6 gallons of water per cubic yard.
- A minimum of 6 days curing time, while keeping concrete moist by misting several times each day.
- When concrete will be subjected to freezing and thawing, an air content of 6% is necessary.
- For most applications such as concrete steps, sidewalks, floors, driveways, etc, mix using this 6 part ratio; 1 part Portland cement, 2 parts sand, 3 parts gravel or crushed rock.
In addition to accurate mixing, properly pouring concrete involves several aspects: screeding (leveling), vibrating (eliminating voids in the slab), troweling (finishing the surface), and jointing (adding expansion joints for large slabs to expand and contract without breaking or cracking).
Consider a Professional
If this all sounds more complicated than what you are willing to undertake, consider enlisting the services of a reliable concrete masonry contractor or concrete construction contractor for the job.
For locating a Houston concrete contractor, for instance, it couldn't be easier than tapping into the project-owner-to-contractor services available online through TrustedPros.com
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Project owners can view contractor portfolios and credentials online at TrustedPros.com 24-hours a day. And then make contact with only those contractors of their choosing for their concrete project - or none at all.Posted by: TrustedPros