Post Date:15,Apr,2024
Analysis of the role of concrete admixtures:
Concrete admixture is a chemical substance added during the concrete preparation process. It can change the physical properties and working performance of concrete, thereby optimizing the performance of concrete. First, concrete admixtures play an important role in improving concrete properties. On the one hand, it improves the strength and durability of concrete. By adding an appropriate amount of admixtures such as reinforcing agents and retarders, the compressive strength, tensile strength and freeze-thaw resistance of concrete can be increased, and the overall mechanical properties of concrete can be improved. On the other hand, it can also improve the chemical resistance of concrete. For example, adding admixtures such as waterproofing agents and preservatives can reduce the penetration of moisture and chemicals into concrete and improve the durability and service life of concrete. Secondly, concrete admixtures play an important role in regulating the working performance of concrete. Working performance refers to the plasticity, fluidity and pourability of concrete during construction. By adding admixtures such as water reducing agents, tackifiers and plasticizers, the fluidity and adhesion of concrete can be changed, making it have better plasticity and fluidity, making construction operations and pouring easier. In addition, adding admixtures such as air foam agents and stabilizers can also control the bubble content and stability of concrete to adapt to different engineering needs.
Research on specific application measures of concrete admixtures:
(1) Application of water reducing agent
From the perspective of the performance of the water-reducing agent, its water-reducing enhancement effect is more obvious, and it has rich technical connotations. If you want to ensure the overall slump of concrete materials, if you can combine the advantages of water reducing agents, you can effectively reduce the amount of concrete water used in the unit and reduce the overall water-cement ratio, thereby achieving the development goal of improving the strength of the concrete structure. At the same time, the effective use of this method can also better improve the density and durability of concrete materials. If the overall water consumption of concrete materials remains unchanged, combined with the advantages of water reducing agents, the fluidity of concrete materials can be further improved. While maintaining the stability of concrete strength, the use of water-reducing admixtures can also achieve the development goal of reducing cement consumption. Reduce unnecessary construction cost investment and reduce cost expenditure. At the current stage, various forms of water reducing agents have appeared on the market. Different types of water-reducing agents have extremely obvious differences in terms of scope of application and use effects. Workers need to use them effectively based on the actual situation on site.
(2) Use of early strengthening agent
Early strength agent is mainly suitable for winter construction or emergency repair projects. If the temperature of the construction environment is found to be high, or the temperature has been lower than -5℃, this admixture cannot be used. For large-volume concrete materials, a large amount of hydration heat will be released during use, and early strength agents are not suitable for use. At the current stage, the most widely used early strength agents are mainly sulfate early strength agents and chloride early strength agents. Among them, the most obvious benefit is the chlorine salt early strength agent, which contains sodium chloride, calcium chloride and other substances. During the use of this early strength agent, calcium chloride can chemically react with related components in cement, further increasing the solid phase ratio in the cement stone, thus promoting the formation of the cement stone structure. After completing the above work content, it can also reduce the problem of excessive free water in concrete in traditional work, reduce the impact of porosity, and truly achieve the development goals of high strength and high density. It should be noted that the chlorine salt early strength agent is likely to have a certain corrosive effect on the steel structure during use. In view of this problem, this kind of admixture is not suitable for prestressed concrete construction operations. In the research on sulfate early strength agents, sodium sulfate early strength agent is a widely used early strength agent. Judging from its characteristics, it has strong water resistance. And when mixed into concrete materials, it can also undergo a series of chemical reactions with other components in cement, eventually generating the required hydrated calcium sulfoaluminate. After this substance is produced, it can further accelerate the hardening speed of cement. Chloride salt early-strength agents and sulfate early-strength agents are inorganic salt early-strength agents. If corresponding work needs to be carried out at higher temperatures, this early-strength agent cannot be used. In the actual use process, staff need to combine the characteristics of various early strength agents and the actual situation on site to select the most appropriate early strength agent.
Post time: Apr-17-2024