A composite material, concrete consists of fine and coarse aggregate and a fluid cement that hardens over time. Second only to water, it is the most widely used substance in the world. For all of its practical and aesthetic purposes, it is an extremely useful and versatile building material. Regardless of its use, there are many different types of concrete, each of which has a unique set of benefits.
The two main types of concrete are called the nominal mix and the design mix. The former is the most common, and uses a 1:2 cement and sand ratio. The latter is based on laboratory tests that determine the required compressive strength of the material. The former is generally preferred for general construction work. Both of these are useful, but there are some differences. A design mix is generally more durable and stronger than a nominal mix. It may have more or less of each ingredient depending on the structural design and requirements of the project.
Normal strength concrete is a mixture of cement and sand that takes from 30 to 90 minutes to harden. It is typically used for buildings and pavements that do not require a high tensile strength. It is not ideal for other structures, as it cannot withstand the stresses of vibrations and wind loading. Alternatively, it is used in the construction of walls and foundations. The normal strength mix is made of a mixture of cement and sand and is usually suitable for residential construction.
The second type of concrete is the normal strength concrete. It has a ratio of 2:1 cement and sand, and takes 30 to 90 minutes to set. The purpose of the nominal mix is to produce a concrete with a high compressive strength for the project at hand. This type of concrete can be used in building construction, but is not recommended for structures with high tensile or flexural strength. It is also not suitable for use on bridges and other structures.
A mix of cement and sand is necessary for the proper strength of the concrete. Its composition depends on the aggregate used and on the design. A nominal mix can be made to suit any shape or structural system. Its constituents include cement, sand, pigments, and reinforcement. Once the mix is completed, it is ready for use. It can be placed on almost any surface. A typical structure needs a base, an upper floor, and a foundation.
The first type of concrete is the nominal mix. This is used for ordinary construction. This mix is typically made with a 1:14 ratio of cement and sand. The resulting mix will be 150 pounds per cubic foot. It is important to avoid excessive handling because it can cause segregation of coarse and fine aggregates. The normal mix weighs 150 pounds per cubic foot and is ideal for construction projects with a large volume of material. This type of concrete is suited for highways and is not considered strong for buildings.