8 common misconceptions about lime application
Lime, as a basic building material and industrial raw material, is widely used, but there are often some misconceptions in its use, which may affect its effectiveness and even bring hidden dangers.
Misconception 1: Mixing quicklime with hydrated lime. Lime (calcium oxide) reacts violently with water and releases heat, mainly used for disinfection and drying; Hydrated lime (calcium hydroxide) is used for masonry and plastering. The chemical properties and uses of the two are different and cannot be arbitrarily replaced.
Misconception 2: The shorter the lime aging time, the better. Hydrated lime needs to be fully aged to completely dissolve, otherwise undigested particles will absorb water and expand inside the wall, causing "explosion" and foaming, seriously affecting the quality of plastering.
Misconception 3: Lime mortar can be stored indefinitely. Lime paste will gradually carbonize in the air, reducing its activity. Long term exposure to lime mortar will cause failure, and it should be prepared as needed to avoid using hardened mortar.
Misconception 4: Lime can kill all pathogens. Lime is effective for most bacteria, but its killing effect on spores, viruses, etc. is limited, and its disinfection effect is affected by concentration and environmental humidity, and cannot completely replace professional disinfectants.
Misconception 5: The more lime used, the better the soil improvement effect. When used to improve acidic soil, excessive application of lime can damage soil structure, cause compaction, and affect the availability of trace elements. Scientific application should be based on soil testing results.
Misconception 6: All lime is suitable for painting. High quality block ash matured fine lime paste is suitable for painting. Lime with industrial by-products or impurities has poor color and weak adhesion, which can easily cause wall peeling.
Misconception 7: Lime can be mixed with other materials at will. Lime is an alkaline material and should not be mixed with acidic substances such as ammonium nitrogen fertilizers, otherwise it will cause nitrogen loss. When mixing with cement, attention should also be paid to the ratio and timing.
Misconception 8: Lime construction does not require special protection. Quick lime releases heat when it comes into contact with water, and is irritated by hydrated lime dust. When operating, gloves, goggles, and masks should be worn to avoid skin burns and respiratory discomfort.
