How to assess the efficiency of a stone consolidant ?

1. How to assess the efficiency of a stone consolidant? -The example of the Bologna Cocktail- Claire Moreau University of Reims, France

2. Products • Bologna Cocktail (Nonfarmale, 1976) (BC): Paraloid B72 Dry Film 104 Solvent mixture (Acetone, Butanone, Toluene, Butanol) • Silicic Acid Ester (SAE): Remmers 300E

4. Before ageing (km/s) After ageing (km/s) Width 5.7 2.2 Length 6.4 2.5 Height 5.8 2.1 Ultrasonic velocities Artificial weathering Marble after thermal ageing (500ºC)

5. Methods for the evaluation of the penetration depth of a consolidant Iodine staining Microprobe analysis Microdrop test Ultrasonic velocity measurement Drilling resistance measurement Bi-axial flexural strength measurement

6. Bologna Cocktail -> 2.7 mm SAE -> 12.5 mm Iodine Staining(Kumar and Ginell, 1997)

7. Microprobe analysisX-Ray mapping of Silicon

8. BC: Hydrophobic surface SAE: Less hydrophobic, presence in depth (~12.5mm) Untreated range Microdrop test

9. Untreated range Ultrasonic Profiles Decrease of the velocity along the depth Better penetration of SAE than BC

10. Derivative of the velocity on depth(DV/Dx)as a function of depth BCC, BC5+SV, SAE: Homogeneous profiles

11. Drilling Resistance(Tiano and al., 2000) SAE: Higher drill resistance in the first 10mm

12. Load F Slice (thickness h, radius R) Bi-axial flexural strength(Wittmann and Prim, 1983)

13. Untreated range Bi-axial flexural strength profiles Better penetration of SAE than BC

14. Derivative of biaxial flexural strengthsbzon depth(Dsbz/Dx) (N/mm³) as a function of depth Non-homogeneous profiles

15. Strength – E-modulus Linear correlation for a substrate

16. Conclusion