Learn How We Use Additives and Structural Filler
When creating a batch of new concrete, it’s important to be aware of the environment surrounding where the concrete will be placed before even creating a new batch. This dictates which additives or fillers are included in the mix, allowing a more accurate, durable, and long-lasting concrete to be created for each project. Since Permacast Precast Concrete Fencing & Walls is created in-house, we can control the entire process from start to finish. For us, it’s not just important to create the right concrete; it’s important to create concrete in the right ways.
Our additives create more strength with fewer chips or breaks than concrete poured on-site. Plus, we have no fly ash for strength because it will slow the curing process. We take a full 24 hours to cure our precast concrete, and the additives we choose are specific to each project. Here are some of the admixtures that comprise our precast concrete:
Often used in larger construction projects, water-reducing additives reduce the amount of mixing water needed to produce concrete of a certain slump. Used to obtain a specific concrete strength, these additives reduce the amount of cement content, resulting in lower CO2 emissions and energy usage per volume of concrete produced. This is often used in projects in which the reinforcing steel requires higher workability, such as bridge decks, low-slump concrete overlays and patching concrete.
Most often used for modifying the properties of concrete in cold weather, accelerating additives speed up the rate of early hydration in cement. These can also reduce concrete setting time. Most commonly, calcium chloride (CaCl2) is the chemical chosen for this process. While adding CaCl2 to a cement mixture could cause corrosion of steel reinforcements, following concrete best practices when mixing like proper consolidation, adequate cover and proper concrete mix design should prevent corrosive activity.
Air-entrainment admixtures introduce microscopic air bubbles into the concrete mix to help stabilize the mixture, preventing cracking and increasing concrete’s freeze-thaw durability. This admixture will also reduce water bleeding and segregation as the concrete settles, and provides a high resistance to cycles of wetting and drying. The increased cohesion provided by air entrainment admixtures will allow for more workability and durability in the resulting concrete.
Shrinkage in concrete is caused by water loss, leading to a stress in the concrete that can result in cracking or curling. This admixture, introduced in the initial stages of mixing, prevents that shrinkage from occurring by reducing the stress of water loss on the concrete. This leads to more durable concrete as well as longer-lasting aesthetic displays.
Corrosion can occur when the steel reinforcements are exposed to chloride salts over time. By including corrosion-inhibiting admixtures, the steel reinforcements in your concrete will be safe from corrosion for years to come. This admixture works for many years to reduce rusting and corrosion. This will significantly reduce maintenance costs over the life of the concrete. This admixture is typically used in bridges, marine structures or anywhere saltwater and air might be present.
When the setting process starts, many factors work against concrete. High temperatures, for example, can accelerate the setting process, leading to cracks and instability later in the life of the concrete. Set retarding admixtures help protect concrete from the effects of high temperatures and other factors that would cause concrete to set too quickly. These will also reduce cracking due to form deflection as concrete slabs are placed in sections. Set-retarding admixtures can aid in air- entrainment, and water-reduction, as well.
To create beautiful, long-lasting and durable concrete each and every time, Permacast Precast Concrete Fencing & Walls follows industry standards to create the perfect batch of concrete for your next project. By evaluating the construction site and choosing the correct dosages of admixtures, we create perfectly blended concrete that will stand the tests of time and weather. Talk to us about your next project or come to our Lunch & Learn to find out more about how Permacast can serve you.