Whiskering principle
Cement base caulking mortar cement as the main gelled material, CS, C2S, C3S minerals such as;
These minerals in the water of hydration process generates a large amount of Ca (OH) 2, Ca (OH) 2 in water to form the solution. CO2 dissolves in water to form in the air of H2CO3, dissolved in the water film on the surface of the cement mortar;
In the process of evaporation of water, the Ca (OH) 2 with water by capillary migrate to the surface of the cement mortar mortar, mortar and dissolved in surface water film of H2CO3 reaction, generate white CaCO3 precipitation to the caulking mortar and formed on the surface of the ceramic tile whiskering. This process is the main cause of forming whiskering;
Mortar containing soluble alkali, salt dissolves in water to form various ions, along with the water in the process of evaporation of water by capillary migrate to the surface of mortar, mortar of white crystalline form whiskering.
Whiskering classification
First whiskering
Occur in the setting and hardening process of cement mortar
Generally appear within the construction for days or weeks
Construction after the rain is the first time in the short term the typical whiskering exceptions, most of the whiskering is formed.
Whiskering root reasons for cement is in not completely hydrated state, under the condition of environmental conditions suitable for mortar has a large amount of Ca (OH) 2.
Secondary whiskering
Will be born in mortar after hardening
Months or years after construction
Mortar brand damp environment for a long time, mortar and alkali salt forming gradually accumulated in the surface of the wall.
Short-term whiskering through observation, caulking mortar are more likely to happen, if did not happen in the short term whiskering (rain), in addition to the damp, sewer pipe often encounter water, such as the bottom part, whiskering rare phenomenon.
Whiskering reason
From the whiskering mechanism analysis, whiskering form must have three conditions:
Low soluble substances or material itself has a hydration reaction of soluble substance is formed
Low soluble matter of outward migration channels
The carrier of low soluble matter of outward migration
As long as eliminate one of the conditions, can avoid whiskering in theory.
Caulking agent whiskering environmental factors
Low construction and construction within days after high temperature and low humidity low humidity and high humidity
After high temperature and low humidity environment construction, rapid moisture evaporation, low water concentration in the air, the water shortage, lead to too much not hydrated cement mortar of particles, whiskering has occurred on the water; Low temperature and humidity environment, moisture evaporates slow, slurry medium to exist a large number of moisture, dissolved alkaline and salt ions in great quantities, cause whiskering.
Low after construction in rain, snow, fog weather in the short term
Low impact of acid rain
Acid rain infiltration into cement mortar, reacting with internal alkaline substances to form salt solution, along with the moisture migration in the process of evaporation to the slurry surface form whiskering.
Construction factors
The construction way
Easy whiskering jointing construction, construction joints with whiskering.
Construction operations
Low random change ratio of mortar itself;