Fair-faced concrete has been widely used in large-scale construction projects at home and abroad, especially in domestic bridge engineering. However, it has not been promoted and used in domestic general housing construction projects. The superior structural performance and remarkable economy of fair-faced concrete have not yet been obtained. fully use. In the reinforced concrete country Japan, clear water concrete has been widely used in various construction projects. Durability of concrete The ability of concrete to resist various destructive factors during use. The durability of concrete determines the life of concrete works. It is an important property of concrete and has long been highly valued by people. There are six main types of damage that affect the durability of concrete: Freezing-thawing cycle: It is the most common destructive effect, so that people often use frost resistance to represent the durability of concrete. The freeze-thaw cycle creates internal stresses in the concrete, causing the cracks to develop and the structure to be loose until the surface is peeled off or the whole collapses. The role of environmental water: including the soaking effect of fresh water, the erosion of salt water and acidic water. Among them, sulfate, chloride salt, magnesium salt and acid solution can produce severe corrosion under certain conditions, resulting in rapid destruction of concrete. The destruction process of environmental water can be summarized into two kinds of changes: one is to reduce the composition, that is, some components in the concrete are directly dissolved or dissolved after decomposition; the second is to increase the composition, that is, some substances in the solution enter the concrete. Chemical, physical or physicochemical changes occur to produce new products. The increase or decrease of the above components leads to instability of the concrete volume. Weathering: including the circulation of dry and wet, hot and cold. When the temperature, humidity changes greatly, the area changes rapidly, and other destructive factors (such as salt, alkali, seawater, freeze-thaw, etc.) act, it can often accelerate the collapse of concrete. Neutralization: Certain acid gases in the air, such as Cl2, H2S and CO2, reduce the alkalinity of the liquid phase in the concrete under appropriate temperature and humidity conditions, causing decomposition of certain components and changing the volume. . Corrosion of steel bars: In reinforced concrete, the steel bars are rusted by electrochemical action, the volume increases, and the concrete protective layer is swelled. As a result, the corrosion of the steel bars is accelerated. This vicious cycle causes the steel bars and concrete to be seriously damaged at the same time and becomes destroyed. One of the most important reasons for reinforced concrete structures. Alkali-aggregate reaction: the most common is the reaction of SiO2 in cement or water (alkaline Na2O, K2O) and some active aggregates (such as opal, vermiculite, andesite, cristobalite) to form alkali in the interfacial zone. The silicate gel expands the volume and eventually disintegrates the entire concrete building. This reaction is also known as the alkali-silicic acid reaction. In addition, an alkali-silicate reaction is carried out in combination with an alkali-carbonate. In addition, the ability to resist wear, cavitation, impact, and even high temperatures is also included in the range of durability. The various destructive effects described above are often exacerbated by their cyclical alternation and coexistence stacking. The former leads to fatigue of concrete materials; the latter makes the damage process more complicated and complicated and difficult to control. To improve the durability of concrete, it is necessary to start from two aspects of resistance and force. Increasing resistance can suppress or delay the destruction of the force. Therefore, improving the strength and compactness of concrete is often beneficial to the improvement of durability. Among them, the density is particularly important, because the hole is often the way to break into the concrete interior, so the impermeability and frost resistance of concrete are closely related. On the other hand, by improving the environment to weaken the force, the durability of the concrete can also be improved. In addition, admixtures (such as antifreeze for air entraining agents), cautious selection of cement and aggregates, blending of polymers, coating materials, etc., can be used to effectively improve the durability of concrete and extend concrete engineering. Safe use period. Durability is a long-term performance, and the damage process is complicated. Therefore, there are still many difficulties in conducting tests and evaluations more accurately. Now only using rapid simulation test, the method of comparing and testing one or several performance changes under one or a few damage factors is not ideal, and the evaluation criteria are not uniform. For the damage mechanism and similar laws There is a lack of in-depth research, so the durability of concrete has so far been difficult to predict. In addition to laboratory rapid testing, long-term exposure testing and engineering observations to accumulate long-term data will contribute to the correct assessment of durability. good quality TUV ENEC CE four wires three circults lighting track rail .The same as Powergear lighting. four wires three circults lighting track rail, Lighting Track Rail Farwise Technology Co.,Ltd. , https://www.farwiselighting.com