There are many factors to measure the quality of concrete performance, durability is one of the very important indicators, if the durability is not enough, will lead to serious consequences. Thus, in the concrete configuration, how to improve the durability of concrete is a problem that engineers have been thinking about, the following we will understand some of the factors that affect the durability of concrete.
The use of high-grade cement
There are many factors that affect the durability of concrete, not only the impact of the concrete configuration process of adulterated substances, but also need to pay attention to the quality of cement, such as the strength of the cement in the configuration process, varieties, aggregates and other factors of its own. In the actual project, we should consider the specific situation, and through scientific testing, so that the concrete to achieve the required high strength, high durability and high fluidity. The preparation of high-strength concrete should use 525 # or 625 # of silicate cement or ordinary silicate cement. When formulating concrete strength C50 ~ C80 cement dosage can usually be 400 ~ 500kg/m3, for C100 above, the cement dosage can also be controlled within 500kg/m3.
Mixed with high-efficiency water reducing agent
After mixing with water, cement will produce a flocculent structure. In these flocculent structure, wrapped with a lot of mixing water, thus reducing the workability of fresh concrete. In order to maintain the required workability of the concrete mix during construction, it is necessary to increase the amount of water used during mixing accordingly, which will promote the formation of excessive pores in the cement stone structure.
When the water-reducing agent is added to the directional arrangement, so that the surface of the cement masses are all equally charged. Under the action of electrical repulsion, not only make the cement system in a relatively stable state of suspension, but also in the cement particle surface to form a layer of solvent water film, while making the cement flocculation body of free water released, thus achieving the purpose of water reduction.
Mixed with active minerals and micro silica fume
The lack of hydrate stability in the cement stone of ordinary cement concrete is another major factor that the concrete cannot be super durable. The purpose of mixing active minerals and micro silica fume in ordinary concrete is to improve the composition of cementitious material in concrete.
The active minerals and micro silica fume contain a large amount of active Si02 and active A1203, which can produce a secondary reaction with free lime and high alkaline hydrated calcium silicate produced in the hydration process of Portland cement to produce low alkaline hydrated calcium silicate with higher strength and better stability, so as to improve the composition of hydrated cementitious substances, eliminate free lime, make the cement stone structure more dense, and block the possible formation of permeation paths.
In addition, it also improves the interfacial structure of the aggregate and cement stone and the properties of the interfacial zone. These important effects contribute essentially to the improvement of the durability and strength of concrete.
Eliminate the structural damage factors of concrete itself
In addition to environmental factors caused by the concrete structure damage, some physical and chemical factors of the concrete itself, may also cause serious damage to the concrete structure, resulting in concrete failure. To improve the durability of concrete, it is necessary to reduce or eliminate these structural damage factors. Limit or eliminate the introduction of alkali from raw materials, S03, Cl- and other substances that can cause damage to the structure and erosion of the steel content, strengthen the construction control links to avoid shrinkage and temperature cracks, in order to improve the durability of concrete.
Ensure the strength of concrete
Although strength and durability are different concepts, but closely related, the essential link between them is based on the internal structure of concrete, both directly related to the water-cement ratio of this factor. Under the condition that the concrete can be fully compacted, with the reduction of water-cement ratio, the porosity of concrete decreases and the strength of concrete increases continuously. At the same time, as the porosity decreases, the permeability of concrete increases, and thus various durability indicators are also improved. In the current high-performance concrete, in addition to the incorporation of high-efficiency water reducing agents, but also the incorporation of active mineral materials, they not only increase the denseness of the concrete, but also reduce or eliminate the content of free calcium oxide. While substantially improving the strength of concrete, but also substantially improve the durability of concrete.
Silica Fume Supplier
As a reinforcing agent for concrete, microsilica fume can not only improve the durability of concrete, but also improve various properties of concrete, such as strengthening the corrosion resistance, strength, flame retardant properties, frost resistance, etc., to extend the service life. Therefore, to protect the quality of concrete projects, the purchase of micro silica fume is also particularly important, to choose the production of experienced, large-scale manufacturers to cooperate, Henan Superior Abrasives professional production of micro silica fume for various purposes, welcome to consult.
