Calgary Concrete Pros
What Is Concrete?
Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to a solid over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminum combined. When aggregate is mixed with dry cement and water, the mixture forms a fluid slurry that is easily poured and molded into shape. The cement reacts with the water through a process called concrete hydration that hardens it over several hours to form a hard matrix that binds the materials together into a durable stone-like material that has many uses. This time allows concrete to not only be cast in forms, but also to have a variety of tooled processes performed. The hydration process is exothermic, which means ambient temperature plays a significant role in how long it takes concrete to set. Often, additives (such as pozzolans or superplasticizers) are included in the mixture to improve the physical properties of the wet mix, delay or accelerate the curing time, or otherwise change the finished material. Most concrete is poured with reinforcing materials (such as steel rebar) embedded to provide tensile strength, yielding reinforced concrete.
In the past, lime-based cement binders, such as lime putty, were often used but sometimes with other hydraulic cements, (water resistant) such as a calcium aluminate cement or with Portland cement to form Portland cement concrete (named for its visual resemblance to Portland stone). Many other non-cementitious types of concrete exist with other methods of binding aggregate together, including asphalt concrete with a bitumen binder, which is frequently used for road surfaces, and polymer concretes that use polymers as a binder. Concrete is distinct from mortar. Whereas concrete is itself a building material, mortar is a bonding agent that typically holds bricks, tiles and other masonry units together. Grout is another material associated with concrete and cement. It does not contain coarse aggregates and is usually either pourable or thixotropic, and is used to fill gaps between masonry components or coarse aggregate which has already been put in place. Some methods of concrete manufacture and repair involve pumping grout into the gaps to make up a solid mass in situ.
Common Types Of Concrete
Reinforced Concrete
As you may have guessed by its name, reinforced concrete has reinforcements, unlike plain concrete. Reinforcement typically comes in the form of steel bars, rods, or mesh embedded into the concrete. What this does is increases the strength of the resulting material. In contrast to plain concrete, reinforced concrete has more compressive and tensile strength. Most concrete applications need a certain element of reinforcement.
Ready-mix Concrete
Ready-mix concrete refers less to its inherent properties and more to its preparation. This type of concrete refers to concrete that’s mixed at a central location before being distributed to different job sites. Contractors must transport the mixed concrete quickly to prevent it from hardening. Ready-mix concrete is transported by the familiar concrete trucks we see. Once these trucks arrive at their respective construction sites, the concrete may be used immediately.
Asphalt Concrete
Asphalt concrete, or simply asphalt, is a composite material used in airport runways, roads, and pavements. Asphalt grew in popularity back in the 1800s because of the rise of automobiles. Since then, new methods and technology have emerged in paving asphalt. Asphalt is known to have a number of desirable properties that make it perfect for roads. It’s durable, workable, skid-resistant, fatigue-resistant, and flexible. However, the mixture must be properly engineered and placed to get the most out of it. Asphalt comes in even more sub-types, which we won’t get into right now.
Lime Concrete
Limecrete, a portmanteau of lime and concrete, is a type of concrete that uses lime instead of Portland cement in its mix. Concrete with lime cement is one of the oldest kinds, being over 5000 years old. Compared to Portland cement, lime is the more environmental and healthy option. Lime is a non-toxic material that readily absorbs humidity, preventing mold formation. Limecrete is more flexible and workable than plain concrete, but it’s not as strong and takes a while to set. Despite its weaknesses, you can see it being used in vaults, domes, and floors.
Prestressed Concrete
Many large-scale megaprojects use prestressed concrete units. This particular type of concrete goes through prestressing to mold it to the required shape. It is similar to reinforced concrete because it also has steel reinforcements embedded into it. Creating prestressed concrete requires an extensive process that increases its strength. The construction of large structures, such as flyovers and bridges, requires prestressed concrete.
Precast Concrete
This type of concrete is typically cast and molded in a separate factory, similar to ready-mix concrete. Precast concrete is created to meet individual specifications before it is transported to the site to be assembled. This type of concrete is typically used for:
- Concrete blocks
- Precast walls
- Staircase units
- Poles
Lightweight Concrete
What makes this concrete unique is that it uses pumice rock instead of other rock aggregates. Lightweight concrete has a density of less than 1920 kilograms per cubic meter. Because it is less dense, it is used more for protection than for its structural qualities. You will often find lightweight concrete as insulation for water pipes as well as in the construction of long-span bridge decks.
High-density Concrete
Dense concrete is used for its radiation shielding capabilities. It has a density of 3000 to 4000 kilograms per cubic meter and consists of high-density rocks or aggregates and man-made materials, such as iron and steel. It’s used in places that require counterbalancing, ballasting or stabilizing. You will often see this type of concrete in the construction of atomic power plants, where radiation shielding is paramount.
Rapid-set Concrete
If you’re in a hurry to complete your project, rapid-set concrete is perfect. As per its name, rapid-set concrete sets in much less time than it takes regular concrete. Additionally, it is resistant to low temperatures, which may be useful for winter projects, where other concrete wouldn’t be.