Epoxy floor paint blisters occur mostly on the first floor or basement, sometimes on the second floor or above. Epoxy floor paint blisters are usually found shortly after construction. Some epoxy pavements are laid in the afternoon. There are blisters. The blister grows from small to large, and it develops to a certain extent and then stops. The higher the temperature, the easier the blisters will occur and the faster the rate of development. Blisters vary in shape and vary in size. Some blisters are more than 1m in diameter and 20~50mm in height.
There is no obvious relationship between the generation of blisters and the construction area. The same area is serious, some are lighter and some are intact. The same group of operations, the same material construction of the epoxy floor, some blisters, some intact, indicating that blisters are caused by a variety of factors.
The reason for blisters is a problem that everyone cares about. When the blisters are cut open, the bubbles contain water or yellowish liquid. The epoxy floor layer is separated from the base layer, and the cement adhered to the base layer is drawn into a peak. See Figure 1-1; according to the "physical" interpretation, in a closed container containing liquid, the liquid evaporates to form a temperature-pressure relationship between the three curves in saturation.
In a closed container, the pressure of saturated water vapor rises with increasing temperature. When the temperature is 20.C, the pressure inside the drum is 0.01 MPa; and when the temperature is between 70 and 80 °C It rises linearly to 0.1MPa; in many areas, the extreme radiant heat of the ground in hot summer days can reach 70.C. At such high temperature, the epoxy adhesive has softened and weakened, so the shape is the same. Like the air, the epoxy floor layer is bulged and the glue is pulled into a honeycomb shape; some of the epoxy layer and the ground part without blister are not firmly adhered, and the contact part is carefully observed. The part that cannot be cured is because the epoxy has moisture and cannot be cured; then where does the moisture come from? There are mainly the following sources of water:
1. The base layer, such as cement mortar leveling layer, has a maximum moisture content of about 12%, and the maximum water content of the base layer is larger than the leveling layer.
2. Dehydration in other ingredients in the epoxy is endless.
3. Epoxy and base layer construction does not combine well to leave voids and the chemical activity of the epoxy itself, not completely cured or in the presence of residues or gases that are not fully cured by moisture.
4. Moisture gas infiltrated underground in the basement.
From the above four aspects, the moisture of the base layer is the main one, and the absolute dry base layer is not. The water content does not determine whether the epoxy floor will produce blisters. Some of the water vapor and epoxy residues in the base layer are encapsulated in the epoxy and the base layer to form bubbles of different sizes, since the epoxy layer itself is not Water vapor, water vapor can not be discharged, leaving the foaming root seedlings. Therefore, the bubbles are generated on the plane, mostly between the base layer and the epoxy layer; the moisture in the base layer is difficult to avoid, which is an important factor causing the epoxy floor layer to blisters.
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