Polyurethane flooring is widely used in foundation lifting and settlement repair due to its light weight, high strength and fast curing properties. However, there is a risk of excessive expansion or bulging when constructing in special environments such as high temperature or humidity .
1. Common causes of bulging
Difference in thermal expansion coefficients of materials:
Polyurethane resin releases heat during the curing reaction, resulting in a certain volume expansion, while the filling material (such as ceramic particles) has a lower thermal expansion. The difference between the two causes stress concentration, which can easily lead to bulging or surface cracking.
Improper base treatment
If the moisture content of the foundation is too high, the water will evaporate into steam during high-temperature construction. The closed polyurethane layer will “trap” the water vapor inside, causing air pressure accumulation, thereby “lifting” the cured surface layer.
Defects in the construction process
, such as excessive one-time paving thickness, uneven particle embedding or insufficient rolling, will cause uneven resin curing or unbalanced shrinkage, increasing the risk of local deformation.
2. Preventive measures and construction suggestions
In order to effectively avoid quality problems caused by excessive expansion, it is recommended to start from three aspects: environmental control, material selection and process optimization :
1. Environmental adaptability adjustment
- Try to choose the morning and evening when the temperature is lower for construction;
- If working in hot summer, you can build a sunshade to avoid direct sunlight;
- The temperature of the material should be controlled below 25°C before use;
- The moisture content of the foundation should be controlled below 3%, and it needs to be dried for more than 48 hours after rain or use infrared drying equipment.
2. Optimization of material ratio
- nano-silica to the formula can effectively improve the thermal stability of polyurethane;
- Select ceramic particles with reasonable grading to strengthen the filling skeleton structure and improve the overall density.
3. Construction technology upgrade
- Implement layered construction , with each layer thickness controlled at 4-5mm, and lay the second layer after 30 minutes;
- Use vacuum rollers to exhaust air in time , and focus on strengthening the compaction of corners and joints;
- a breathable curing blanket during the initial setting stage to reduce the thermal stress concentration caused by local temperature rise on the surface.
3. Professional material selection to prevent and control bulging problems at the source
In polyurethane floor projects, it is very important to choose the right foaming resin and construction system . Spc can provide polyurethane materials specially used for floor lifting, which has the following advantages:
- Precise expansion control : controllable expansion ratio to avoid bulging and hollowing;
- Strong thermal stability : reacts evenly, does not explode, and does not deform in high temperature environments;
- Construction-friendly : Supports construction technology and is suitable for a variety of foundation environments;
- Green and environmentally friendly : low VOC formula, safe and reliable, suitable for commercial and residential areas.