Concrete admixtures

To improve the quality of concrete without significantly increasing the cost of its production, manufacturers use various additives and impurities. All these additives are usually divided into several large groups: plasticizers; modifiers; strength gain accelerators; supplements for mobility; self-compacting additives; frost-resistant additives; complex supplements.
When the artificial stone hardens, they make it stronger, while simultaneously reducing the consumption of the binder. Also, the use of plasticizers allows you to increase the density and improve the water resistance of the mixture. Modifiers improve production characteristics, making it possible to obtain a high-strength concrete mixture when using lower grades of cement. Strengthening accelerators can significantly accelerate this important technical characteristic of an artificial stone, reducing the set time to 3-4 days.
Additives for maintaining the fluidity of the mix increase the setting time and are used when it is necessary to transport the concrete mix over long distances in the summer. Self-compacting additives are used in the manufacture of thin-walled and reinforced blocks or other structures where it is difficult or impossible to use traditional vibrating tools for compacting concrete mass. Frost-resistant additives can significantly increase the frost resistance of concrete.

Varieties of pigments and their properties

Pigments are used to change the color of concrete structures. In industrial production for these purposes are used: carbon black; titanium dioxide; chromium oxide; umbra. All pigments act on the concrete mix in the same way: they absorb part of the light waves, while waves with a different length reflect. Such pigment additives are highly resistant to ultraviolet light, do not fade in the sun, are not washed off by rain, and are resistant to aggressive chemical environments.

Concrete classification

n construction, concrete types are classified according to several parameters. Most often, artificial stone is classified: by strength; by density; by the type of binder; frost resistance; for water resistance; by abrasion; by the rate of strength gain.

Strength rate Strength rate (hardening)
important indicator of concrete structures, on which the time of their commissioning or the time of finishing work depends. Strength is gained in an abrupt manner: in the first 5-7 days after pouring or manufacturing, the hardening indicator reaches 70%, by the end of 28 days it approaches 100% (subject to humidity and temperature conditions). After this period, the strengthening of concrete structures continues and can last for several years

There are 2 types of concrete mixes:
fast-hardening and slow-hardening. To determine the rate of strength gain, the% strength of a 2-day concrete structure is divided by the% strength of the same structure after 28 days. With an indicator of more than 0.4, the structure is classified as fast-hardening. A value less than 0.4 indicates slow hardening.

Curing conditions

The speed at which concrete structures gain strength is greatly influenced by the conditions in which the material hardens. The optimal conditions for its hardening are considered to be a temperature corridor of + 18 ... + 22 ° C and a relative humidity of the environment of at least 90%.
The lower the ambient temperature, the slower the hardening of concrete structures. At 0 ° C, the hardening process stops completely. High temperature leads to concrete dehydration, which also causes a slowdown or complete cessation of the hardening of a concrete structure and a shortage of its strength.

The service life of the constructed building or structure directly depends on the strength and reliability of concrete structures. Therefore, even before the start of construction, you need to decide what brand and what technical characteristics of the material are best suited for solving the tasks.

The difference between concrete and cement: by purpose and composition, by additional admixtures

Cement and concrete - what is the difference between these materials, most people cannot immediately tell. The use of both types of mortars in construction makes it possible to obtain large-sized structures, which are the basis for the construction of various structures. In addition, cement and concrete are used for interior decoration, for example, when pouring floors.
Designation of concepts Cement - a special solution, which is obtained by mixing sand, cement fractions and water, is used for the installation of various structures, laying out walls and other installation work. Builders introduce plasticizers into cement, which serve to increase strength. They give the solution such qualities as moisture resistance, frost resistance. With concrete is called a composite material in which cement, water and aggregates are mixed (most often different grades of crushed stone and other components are used). In addition, there is concrete obtained by hardening a special mixture. For More Details Visit : contractorsconcrete