Ready Mix Products: What Mix Design Is Right for My Application?
When you work with concrete ready-mix products, the right design means everything.
The American Concrete Institute (ACI) notes that concrete proportion selection involves a “balance between economy and requirements for placeability, strength, durability, density, and appearance." ACI 211.1 is the standard used when designing a concrete mix.
Placeability, for example, refers to the traits that wet concrete has so it can be placed and finished. To achieve this placeability, the mix must be adjusted so it doesn’t segregate but instead can be consolidated. Most people measure placeability by slump.
Ready-mix concrete elements:
Aggregates - Gravel or crushed stone can form the coarse aggregate includes crushed stone or gravel. Sand is a common example of fine aggregate.
Water - Concrete strength depends on how much water is used in relation to cement (also known as the w/c ratio).
Cement - Used with water, cement helps produce a paste that connects various aggregates.
Key considerations include the strength and slump. You also need to determine the use of air bubbles, the size of aggregate and whether fly ash should be used. And, of course, you must decide how you’ll adapt if the day is especially cold or hot.
It’s important to know that the process of mixing concrete involves more than just figuring out the proportions of each element.
Besides considering how much cement is in the mix, you also need to weigh everything from potential shrinkage to permeability with ready mix products.
When developing the mix, recognize that demands change over the concrete’s lifespan. There are one set of considerations for freshly poured concrete, another for newly finished concrete and a final set for as a long as the concrete exists.
As a ready-mix supplier, Mack Industries collects the right project information to help ensure that concrete will be attractive for years and years. When we know how the concrete will be used, we can design the proper mix.
For example, we note the desired consistency of the fresh concrete before it dries. We also select the maximum aggregate size, recognizing that there’s less shrinkage and curling when targeting a larger size.
Initially, we use small amounts and make any needed adjustments before producing large batches.
Concrete can be adapted to many different functions and is price-friendly. When you consider stamped concrete, colored concrete and concrete pavers, you can design driveways, countertops or garden project in a variety of ways to suit your needs. Choose a mix appropriate for that design (including colors like red, brown, blue and white). In addition, chemicals can be added to the aggregate to stain, glaze or etch the finished project.
If you’re pouring a driveway or making stairs, you will need a higher strength mix, which is measured in pounds per square inch (PSI).
An outdoor concrete project may be exposed to a wide variance in temperatures in a year. You may want an entrained air mixture that intentionally holds very small air bubbles. This improves the durability of the concrete surface that will be exposed to freezing and thawing.
Cement mix choices also must factor in any local building codes and the type of weather conditions that could exist over many years.
With proper planning, you can confidently use ready-mix products that are meant to last. For more information about our products, contact Mack today or call (800)-482-3111.