The use of high-quality concrete requires careful preparation and engineering. The right mix of ingredients is essential in ensuring that the building material will last a long time. It is important to maintain the right temperature, water, and air conditions to maximize its strength and durability. Several environmental factors can affect the strength of concrete dich vu bom be tong. Too much moisture or heat can cause it to dry prematurely, reducing its ability to withstand unequal tensile stresses. The combination of these factors can also result in low concrete strength.
Ordinary constructions usually require a nominal mix of cement, sand, and water. These are usually made with a 1:2:4 ratio. For more complex projects, the design mix depends on the ratios finalized through laboratory tests. This mix is ideal for construction that requires high compressive strength and ductility. Machine-mixed concrete is the best choice for buildings, bridges, and other structures. Unlike hand-mixed concrete, this one can be mixed on-site.
There are two different types of concrete: normal and strong. The former uses a 1:2:4 ratio of sand and cement, and is the most common mix. It takes 30 minutes to 90 minutes to set. This type of concrete is best used for buildings and pavements that do not require high tensile strength. However, it cannot withstand the stresses that come from wind loading or vibrations. This type of concrete is often considered unsuitable for building foundations.
During construction, it is common to add admixtures, or additives, to the mix. These can decrease the time that the concrete is in the process of setting. In addition to speeding up the process, they can reduce the amount of heat the concrete creates. The amount of these additives depends on the application of the concrete. For example, in thin building sections, small coarse aggregates are required. In the case of large dams, large coarse aggregates are required. The admixtures used in a large dam need to be of consistent size and shape, while a continuous gradation of particle sizes is needed to make a paste with an optimal quality.
Besides sand and cement, the other component of concrete is the aggregates. Aggregates make up sixty to seventy percent of the volume of concrete, depending on the use and thickness of the building. The purpose of the concrete determines the type and size of the aggregates. For a thin building section, small coarse aggregates can be used. In a large dam, large fine aggregates are used for strength. The size of the aggregates is a critical factor when mixing the material.
In construction, there are different types of concrete. The normal mix is used in most situations. This type of concrete is made of sand, gravel, and cement, and it takes about thirty to ninety minutes to set. It is best used for building structures that do not require a high level of tensile strength. It is also not good for pavements. The optimum ratio of these three materials will depend on the structure.