Restoration processes in historical structures require sensitivity to preserve the original features of the buildings. The cement used in this process must be compatible with other materials in the structure.
In-depth examination of special types of cement
- Natural hydraulic lime (NHL):
- Characteristics: Slow hardening, low strength, high vapor permeability.
- Applications: Ideal for exterior facade repairs, historical wall mortars, and floor coverings.
- Application recommendations: Suitable for regions with high humidity. Surface protection may be needed after application.
- Pozzolanic cements:
- Characteristics: Low alkali levels, sustainability, low CO2 emissions.
- Applications: Suitable for foundation repairs, underwater structures, and historical buildings in saline environments.
- Application recommendations: Can be mixed with different lime ratios depending on the pozzolan content and specific requirements.
- Gypsum-based cements:
- Characteristics: Fast setting, low thermal conductivity, breathability.
- Applications: Suitable for interior wall repairs, ceiling restorations, and fresco restoration.
- Application recommendations: Adequate ventilation should be provided to allow proper drying after application.
Additional benefits of using special cement
- Thermal compatibility: In historical structures, old building materials may have different thermal properties compared to modern materials. Special cements provide thermal compatibility, preventing cracking or deformation in the structure.
- Chemical resistance: Historical buildings must resist external threats like acid rain, salt crystallization, and other environmental factors. Special cements offer durable protection against such chemical attacks.
- Texture and color matching: Special cements deliver results that are closer to the original texture and color of historical structures. This is essential for maintaining visual integrity during restoration.
Important considerations during application
- Preparation: The restoration area should be cleaned, and any deteriorated mortar or damaged material should be carefully removed.
- Mixing: The cement must be mixed with the correct ratio of water. Ideal mixing ratios vary for different types of cement.
- Curing process: Adequate curing time should be allowed after cement application. Protection from direct sunlight or wind is also necessary.
Conclusion
The use of special cements in restoration and repair processes ensures that historical structures remain long-lasting and maintain their aesthetic integrity. Selecting the appropriate type of cement for each structure and employing proper application techniques play a critical role in preserving these valuable buildings.