Concrete has been a construction staple for thousands of years. Its strength, stability, and versatility make it a go-to material in construction jobs everywhere. At its core, concrete only has a few ingredients: water, cement, and aggregates (rock, sand, or gravel). When mixed together, they harden and become one of the most durable construction materials out there.
Over time, different concrete recipes have been developed for a variety of different needs. Depending on factors like the concrete’s intended use (whether it’s for decorative purposes or to hold significant weight), the location’s climate, and the size of the project, you’ll use different types of concrete mixtures.
There are a couple dozen different types of concrete, but there are five types of concrete that you will most likely work with on both large-scale construction jobs and small home improvement projects:
Reinforced concrete (RCC) is created by adding steel rods (rebar), meshes, or fiber materials inside the wet concrete mixture. These provide additional strength to the dried and cured concrete, making it ideal for high-load structures like columns, ceilings and bridges.
Concrete on its own works well under compression forces, but is weak when it comes to tension. These reinforcement items—most often rebar—are used to add additional tensile force strength. Acting together, the two materials create a composite material that can withstand massive amounts of force from multiple directions. Steel is most commonly used in reinforced concrete since it expands and contracts in different temperatures similarly to concrete, meaning the two won’t crack and separate if one moves more than the other.
Instead of mixing high-density coarse aggregates into the water and cement mixture, lightweight concrete uses low-density aggregates such as pumice, shale, clay, slate, or slate. This type of concrete is ideal for structures that don’t require as many cross sections in the foundation—a design feature seen in many modern, sleek-looking building structures.
While lightweight concrete has a higher compressive strength than traditional concrete, the density is reduced and compromised in the process. And because lightweight concrete has a high water content, it takes longer to dry and cure than other mixtures. Still, since it’s easily transportable, requires little additional support, and has low thermal conductivity, this type of concrete is a cost-effective construction option that doesn’t compromise on structure strength.
Like its name suggests, high-strength concrete is able to withstand more force without breaking than traditional concrete. Compressive strength is the most important factor for this type of concrete. Because it can hold more weight and pressure than other mixtures, it’s a preferred concrete type for large construction projects such as high rise buildings, long span bridges, and high load carrying buildings that were built on soil with low bearing capacity.
To create high-strength concrete, the water-to-cement ratio needs to be as low as possible without compromising the workability of the concrete. Mineral admixtures (such as fly ash and silica fume) can also be added to the concrete to increase its compressive strength.
In addition to its higher compressive strength than other types of concrete, many construction jobs use this mixture because it requires less maintenance and repair. And since the final product can hold more weight with less mixture, it’s a more cost-effective option.
While high-performance concrete can also have a high compressive strength, it’s more often the concrete of choice for many construction projects because of its other impressive building properties. In order to be considered high-performance, the concrete needs to also have high durability, easy placement, rapid strength gain, high permeability, and high resistance to chemicals.
The mixture for high-performance concrete is similar to conventional concrete, but the mixing and curing process is more intensive than in other concrete types in order to meet the high standards in performance and uniformity requirements. Because this type of concrete has superior mechanical properties, it’s often used in structures like high rise buildings, tunnels, nuclear facilities, and for buildings located in harsh environments.
Rather than pouring the concrete mixture at the final construction site, precast concrete is created off-site site using a mold. This concrete type is one of the most versatile options out there, making it a popular option for many residential and commercial projects across a wide range of industries.
One of the draw to precast concrete is that the casts are completely customizable—you can choose the shape, colors, texture, and size you want for the project. Another advantage to precast concrete is that since they’re created in a plant setting, construction workers don’t have to worry about the weather interfering with the setting and curing process (which directly affects the concrete’s strength and durability). Without having to consider weather issues, this speeds up the construction process and allows for work to be done year-round.
This process is often considered faster, safer, and more affordable than using traditional and on-site concrete methods. From parking structures and bridges, to curbs and interior decoration, most buildings and structures today have some sort of precast concrete component.