What Are Aggregates and How Are They Used?
What Are Aggregates and How Are They Used?
CEMEX offers a wide range of aggregate materials for concrete. Aggregates are granular materials that are used with a cementing medium to form concrete or hydraulic mortar. They are key ingredients in the manufacture of concrete, mortar, and other construction materials, and are used in the construction and maintenance of structures such as highways, walkways, parking lots, airport runways and railways.
Concrete aggregates are composed of geological materials such as gravel, sand and crushed rock. The size of the particles determines whether it is a coarse aggregate (e.g. gravel) or a fine aggregate (e.g. sand). The resulting concrete can be used in its natural state or crushed, according to its use and application.
Aggregate materials help to make concrete mixes more compact. They also decrease the consumption of cement and water and contribute to the mechanical strength of the concrete, making them an indispensable ingredient in the construction and maintenance of rigid structures.
The importance of aggregate materials for concrete
Our CEMEX Aggregate plants have both the technology as well as the operational and technical capacity to develop products that meet the requirements and specifications of our clients.
Many types of construction materials, including concrete, asphalt and mortar, utilize aggregates as key ingredients. Using aggregate materials for concrete reduces production costs and increases the resistance of concrete mixes. Crushed aggregates make up for around 60% to 75% of the volume of concrete. These crushed aggregates significantly affect the properties of freshly-mixed and hardened concrete – making it more compact, decreasing its permeability (which makes it more water-resistant), and modifying its heat retention values. To be able to cater for the variety of different uses of aggregate materials, CEMEX offers a wide range of aggregates to accommodate our clients’ needs.
These characteristics make aggregate materials an indispensable ingredient when it comes to building and maintaining roads, sidewalks, parking lots, airport runways, railway tracks, and a range of buildings and roadways. In fact, the design phase of most construction projects generally requires a careful analysis of the source of the aggregates, including their type and size, as well as the material properties of the aggregates needed at various stages of the construction process. In addition to construction projects, aggregates can also be used in drainage, water filtration and erosion control. They can also be used as a fill material in site preparation and embankment projects.
We at CEMEX continuously seek new ways to use aggregates to improve drainage, heat absorption, and other forces that impact the environment. For example, with an adequate mix of cement and aggregates such as sand and gravel, a material can be created that enables the absorption of water and, at the same time, reduces the absorption of heat, mitigating the "urban heat island" effect, which significantly increases the temperature of paved areas.
Types of concrete aggregates
We offer a wide variety of concrete aggregate materials to be able to cater to the individual needs and preferences of each of our clients.
Aggregates can be classified according to their size, origin, mode of fragmentation and composition. It is important to understand the different types of concrete aggregates and their uses to be able to successfully harness their maximum potential at the time of construction. Crushed stone aggregates, for example, are fundamental when it comes to building sand traps on golf courses, as well as in the construction of buildings and roads. On the other hand, gravel offers excellent control over erosion and in the filtration and drainage of water. Used by themselves, aggregates are also useful as fill materials when preparing a site or in embankments. Aggregates such as sand can also be used when creating or restoring beaches, sports surfaces, race tracks, and other recreational facilities.
Aggregate materials are obtained from natural mines of sand or sand and gravel, quarries, deposits, and underground sediments. Examples of aggregate materials include:
- Crushed rock - These products are obtained by extracting rocks and crushing them to the desired size and texture. Rock sources can be igneous, sedimentary or metamorphic.
- Sand - Sand is found in nature. It is a fine composition of stone material and mineral particles and its composition is variable, depending on the source. It can be used for the construction of roads or for the manufacture of concrete. Different types of sand include: sand 4 block; sand 4 dosable; sand 5; sand 4; and sand 5 washed.
- Gravel - Gravel deposits are produced by a natural process of moisture and erosion. There are different types of gravel - ¾ '' and 1 ½ '', seal, hydraulic base, and subbase, for example - which can be used for constructing roads, producing concrete, or for decorative and aesthetic purposes.
- Recycled concrete - Recycled concrete is obtained by breaking, grinding or cutting existing concrete to a desired size. It is usually used as a base on which other construction materials are placed thanks to its compact nature. This creates a firm surface which can be easily built upon.