On the carbon dioxide source in concrete

Concrete is one of the most widely used materials in today's construction field. Its related characteristics and influencing factors have attracted much attention, among which the role and influence of carbon dioxide source in concrete is particularly critical.

Carbon dioxide originates from concrete and has many effects. From a chemical reaction point of view, carbon dioxide can react with certain components in concrete. The cement in concrete will generate alkaline substances such as calcium hydroxide during the hydration process, and carbon dioxide will carbonize with calcium hydroxide. This reaction changes the chemical composition inside the concrete to a certain extent.

In terms of physical properties, the presence of carbon dioxide sources affects the pore structure of concrete. With the progress of the carbonization reaction, the pores in the original concrete are filled with some reaction products, which in turn changes the size and distribution of the pores. Moderate carbonization can improve the compactness of concrete and enhance the compressive strength of concrete to a certain extent. However, if the carbon dioxide source is excessive, excessive carbonization may lead to micro-cracks on the surface of concrete and reduce its impermeability.

Furthermore, the carbon dioxide source is closely related to the durability of concrete. When concrete is in an environment containing carbon dioxide, if its protective measures are not appropriate, carbon dioxide will continue to invade, and the alkaline environment of concrete will be destroyed. Reinforcement in concrete relies on the alkaline environment to maintain the stability of the passivation film. Reinforcement will lose protection due to reduced alkalinity, which will cause steel corrosion and seriously affect the durability of concrete structures.

In order to effectively control the influence of carbon dioxide sources in concrete, it is necessary to start from various aspects. In the selection of raw materials, some cement varieties with different degrees of carbon dioxide absorption or reaction can be selected, and blends can be reasonably matched to optimize the composition of concrete. During the construction process, ensure the vibration quality of concrete, improve its compactness, and reduce the intrusion of carbon dioxide into the channel. At the same time, appropriate protection of concrete structures, such as coating protective coatings, reduce the chance of contact between carbon dioxide and concrete, so as to ensure the long-term performance and stability of concrete structures.