How to assess the efficiency of a stone consolidant ?

-The example of the Bologna Cocktail-

Claire Moreau

University of Reims, France

Products

• Bologna Cocktail (Nonfarmale, 1976) (BC):

Paraloid B72

Dry Film 104

Solvent mixture (Acetone, Butanone, Toluene, Butanol)

• Silicic Acid Ester (SAE):

Remmers 300E

BC5+SVBrush five times,

Rinsing with the BC solvents2 days between each application

BC

BCC Capillary rise for 1 hour

SAE Capillary rise for 1 hour

Artificial weathering

2.15.8Height

2.56.4Length

2.25.7Width

After ageing (km/s)

Before ageing (km/s)

Ultrasonic velocitiesMarble after thermal ageing (500ºC)

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

Iodine Staining(Kumar and Ginell, 1997)

Bologna Cocktail -> 2.7 mm SAE -> 12.5 mm

Microprobe analysisX-Ray mapping of Silicon

0

1000

2000

3000

4000

5000

6000

0 5 10 15 20 25 30 35

Depth (mm)

Tim

e (s

)

BCCBC5+SVSAE

Microdrop test

Untreated range

•BC: Hydrophobic surface

•SAE: Less hydrophobic, presence in depth (~12.5mm)

Ultrasonic Profiles

Untreated range

Decrease of the velocity along the depth

Better penetration of SAE than BC

0

1

2

3

4

5

6

0 5 10 15 20 25 30 35

Depth (mm)

Vel

ocity

(km

/s)

BCCBC5+SVSAE

Derivative of the velocity on depth (V/x) as a function of depth

BCC, BC5+SV, SAE: Homogeneous profiles

-0,3

-0,2

-0,1

0,0

0,1

0,2

0,3

0 10 20 30

Depth (mm)

V/

x (k

m/s

/cm

)BCC

BC5+SV

SAE

Drilling Resistance(Tiano and al., 2000)

SAE: Higher drill resistance in the

first 10mm

0

100

200

300

400

0 2 4 6 8 10 12 14

Depth (mm)

Forc

e (N

)

SAE Untreated

Bi-axial flexural strength(Wittmann and Prim, 1983)

Slice (thickness h, radius R)

Load F

Bi-axial flexural strength profiles

Untreated range

Better penetration of SAE than BC

0

2

4

6

8

10

12

0 5 10 15 20

Depth (mm)

s bz(

N/m

m2 )

BCC

BC5+SV

SAE

Derivative of biaxial flexural strength sbz on depth (sbz/x) (N/mm³) as a function of depth

Non-homogeneous profiles

-1,40

-1,20

-1,00

-0,80

-0,60

-0,40

-0,20

0,00

0,20

0,40

0 2 4 6 8 10 12

Depth (mm)

sbz

/x

(N/m

m3)

BCC

BC5+SV

SAE

Strength – E-modulus

Linear correlation for a substrate

0

2

4

6

8

10

12

14

0 10 20 30 40

E (kN/mm2)

bz (

N/m

m2) BC5+SV

BCC

SAE

Muntreated

Conclusion

0 5 10 15 20

Bi-axial flexural strength

Drilling resistance

Ultrasonic velocity

Microdrop test

Microprobe analysis

Iodine staining

Depth (mm)

SAE

0 5 10 15 20

Bi-axial flexural strength

Drilling resistance

Ultrasonic velocity

Microdrop test

Microprobe analysis

Iodine staining

Depth (mm)

BCC

BC5+SV