1. Ventilated underground tunnel as a contribution for sustainable refurbishment of buildings affected by rising moisture
Jiří PAZDERKA, Eva HÁJKOVÁ
Department of Building Structures, Czech Technical University in Prague,

2. Presentation outline Remediation methods - air cavities
Current design of ventilated underground ducts
New technical solution of air ducts
Drying efficiency - laboratory test
Results and discussion
Acknowledgement
Research project „Analysis of the Effectiveness of Modern Methods of Rehabilitation of Buildings Affected by Moisture“, no. SGS15/128/OHK1/2T/11.

3. Remediation methods - air cavities
Additional protection of buildings against moisture rising from the subsoil
Principle: enable an air flow along the surface of moist structures to ensure sufficient evaporation of moisture from the structure
High demands for the durability of materials used in the structures of the air duct

4. Current design of ventilated underground ducts
Conventional air duct based on a masonry structure

5. New technical solution of air ducts
New sustainable solution: A specially shaped concrete block

6. New technical solution of air ducts
Ventilated tunnel (concrete blocks) installed into a historic masonry building

7. Drying efficiency - laboratory test
Scheme of a laboratory model with air duct in a scale of 1 : 2

8. Drying efficiency - laboratory test
Arrangement of laboratory model

9. Drying efficiency - laboratory test
Laboratory test – Timeline
months

10. Results and discussion
The final values of the moisture readings w [wt. %] , after 3 month of ventilation using
The velocity of the flowing air in the duct 0.05 m/s
Decreased of moisture in the masonry by 43 % on average.

11. Results and discussion
The initial values of moisture after 30 days of using the fan

12. Results and discussion
The final values of moisture after 90 days of using the fan

13. Conclusion
Effective solution for the additional protection of historic buildings against ground moisture - high durability and simplicity
In comparison with contemporary masonry air ducts - more sustainable (higher durability of used structures)
Respecting the original appearance of historic buildings without damage to historic masonry
Moisture in the masonry decreased by 43 % on average compared to the reference sample

14. Thank you for your attention!