Six factors contributing to the pathological changes of black stone in China
1. Natural defects.
Chinese black stone generally has natural defects such as cracks, sand holes, looseness, and inclusions. If these defects are not well repaired and remedied beforehand, once exposed to damp and harmful pollution environments, the defective parts will first develop lesions and damage, and thus expand.
2. Wrong protective measures.
Due to the lack of effective repair of cracks and loose areas in Chinese black stone, the high water pressure caused by moisture can quickly damage the back of Chinese black stone. Another thing is that protective measures have been taken, but water can also enter the interior of Chinese black stone through cracks and loose parts, causing an increase in humidity and forming a vicious cycle.
3. The impact of mining, processing, storage and transportation processes, as well as stone cracking and improper mining methods.
Unscientific mining methods can greatly increase the probability of stone cracking. The hidden danger of rust spots may also be caused by processing iron tools, and some stone cooling liquids may contaminate the stone. Another situation that can cause pollution such as rust spots and yellow grass ropes is improper maintenance during storage and transportation.
4. Adhesive material used for installing stone.
If the wet pasting method of cement paste is used to install the stone, the alkali soluble substances in the cement on the surface of the stone will crystallize, forming a salt precipitation and alkali bleeding phenomenon. In addition, water stains can also seriously affect the appearance of stone. The formation of water stains is due to the fact that some salts formed after cement hydration have the characteristics of desiccants, which absorb moisture from the air on the surface of Chinese black stone. Improper use of bonding materials such as stone adhesive can also cause the stone to turn yellow.
5. Natural environmental factors.
Including acid rain erosion, freezing damage, and environmental pollution.
6. When laying stone, if inferior products are used on the surface of the stone, there will also be many problems.