Paving marbles wet with cement, the moisture within the material into marble after marble surface is not easy to dry and wet natural marks, which is commonly known as water spots.
First, the water forms plaques
marble caused by water spots without making protection
Protectant brushing uneven marble surface water spots caused by
The underside of the marble caused by water leakage spots brush protector
marble side of the drain water spots caused by brush protector
Second, water spots, the discriminant
First wet with water marks at the wet marble, and then measured with a pH test strip a wide range pH, test paper blue (pH value> 7), is alkaline. In addition, no matter how the weather changes, the marble surface is always wet marks could not do, that the use of fire baked the surface, it is difficult to dry.
Third, the type of water spots
From water to analyze the mechanism of plaque formation, mainly in the following types:
1. Hydrated gel size
The main products of cement hydration are alkali - silica gel and so on. Natural marble micro pore capillary action with the surface of the gel-type substances migrate to the surface evaporation of water and solidifies.
For the layer of cement gel (network)-like structure, the specific surface area of 200 ~ 600 ㎡ / g, gel pore size is 1.5 ~ 3nm, only water molecules than an order of magnitude, and highly absorbent, and, with simple heating and drying methods can not make these gel decomposition. Adsorption of the water showed a translucent gel that changes in the reflectivity of light crude looks like a marble by water wetting.
When comparing the shortening of the marble wet paste directly, they often have this type of water spots appear.
2. Hygroscopic salt type
Including cement aggregates brought their excessive use of cement admixture of saline and the soluble salt into the category of the moisture absorption material. These substances can easily absorb saline water classes to absorb moisture, resulting from the formation of hydrate water spots. Serious cases make clear the marble surface of salt spots.
● Cement Aggregate salt carried by itself: the oxide fine aggregate cement include Na2O, K2O, etc., the alkali content of 0.6 to 1.5%, mixed with water produce NaOH, KOH and other water-soluble bases. Part of the activity of silica and aggregates (SiO2) the reaction of alkali - silica gel, part of the compound and set the reaction of calcite powder, calcium hydroxide, sodium carbonate and saline, the excess from the porous marble precipitation.
● the use of cement additives to absorb moisture into the class of soluble salt material: such as cement admixtures in NaCl (antifreeze), CaCl2 (early strength agent), triethanolamine (early strength agent).
In practice, often the water is not a single type of plaque formation, the most common size and moisture gel is hydrated salt-type complementary, because salt has a low hygroscopic water vapor pressure, they adsorbed moisture in the air until the water vapor pressure equilibrium with the outside world, and marble micro-pores and hydrated gels have the additional pressure (pore capillarity) to balance the more favorable adsorption of more water, so no matter what the weather outside, the marble surface layer of water always difficult to dry. Because salt is hygroscopic gel wrapped, in order to clean these water spots are not easy.
Decorative marble for the building is concerned, water is the root of all evil, the marble after the formation of water spots, often also have other symptoms appear, such as water grizzled China, rusty water spots and more.
Fourth, the causes of water spots
The reasons for the formation of water spots, and its composition is complex and marble under different circumstances, the reasons for the formation of water spots are also different, mostly because of the cement mortar, cement additives, acid rain, the role of environmental factors such as the marble of the capillary in the formation of a cement pore silica gel, salt and other hygroscopic material. There are also plenty of water directly into the marble leaving the marble becomes wet inside, strictly speaking, only the water directly into the marble house, it can not be called water spots, truncated connected to water, marbles will gradually self- dry, but in the humid environment, moisture absorption material in the cement mortar into the marble will soon be formed within the real water spots.
Lesions caused by water spots summed up the reasons for the following categories:
1. marble installation because the binder used
Installation of marble with cement alkali content in the high or inappropriate use of cement additives.
2. Install the construction process, excessive water use
Since construction, the fluidity of cement mortar that is not a good grasp of moisture content, water and more saline water can dissolve more easily to form water spots, less moisture content, water containing less salt not easy to form water.
marble in the pavement, in order to ensure the close bond between mortar and marble is usually implemented using a rubber hammer shock, and smooth cement mortar in the same time the density is not possible in real-time water will shock the low density of the site to gather, therefore, density is relatively low cement mortar marble plaque on the surface of the water heavier.
3. The marble itself, the density difference
marble because of its composition, the formation of different conditions, different marbles have a greater difference in density. The density and porosity of marble not the same, its not the same water absorption, low water absorption, high density, low density absorbent larger. The higher water absorption, the easier the formation of marble water spots.
4. Improper maintenance
Some manufacturers or decorative marble construction unit for a purpose directly with acid, alkali cleaning marble, and the residual acid and cement the role of some oxides on the formation of soluble salt, which absorbs moisture and produce water spots (such as in Shandong White Ma marble often such cases occur), while the residual alkali can absorb water directly produce water spots.
In addition, some poor Protectant is the marble the culprit lesions produce water spots.
5. Environmental causes
marble's use of the environment often have water (water continuous) or the state marble in constant rain, the marble is relatively easier to form water spots.
When the marble directly or indirectly connected with the damp or water, for example, installed in the ground floor of marble, while the region's water table has too high, or wet marble he neighborhood pool, flower beds, etc., can often see obvious water spots blotting. This is mainly because the water continued to make the marble has been in a wet state, and cement mortar in the gel-type substances and soluble salt can continue to move across the marble with water and gathered in the marble surface to form water spots. Wet or damp marble, will add to the severity of the water spots. Because the more water, cement mortar and soluble saline gel migration of substances more easily through the marble, marble aggregate surface was also more.
In addition, sometimes because of environmental pollution leaving the color to deepen the local marble, looks like water spots.
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