Overview of Test Program and Sealants Tested

Three commercially available high strength structural silicone sealants, which are currently marketed for bomb blast mitigating window designs, were se­lected for evaluation.

Sealant A is a two-component (alkoxy cure) silicone sealant used for struc­tural glazing applications. Sealant A complies with ASTM C1184 Specification for Structural Silicone Sealant [32].

Sealant B is a two-component (alkoxy cure) silicone sealant used for struc­tural glazing applications. Sealant B complies with ASTM C1184 and ETAG 002 Guideline for European Technical Approval for Structural Sealant Glazing Kits [33], EN 13022 Glass in Building—Structural Sealant Glazing [34], and GB 16776-2005 Structural Silicone Sealants for Building [35].

Sealant C is a one-component neutral cure (alkoxy) silicone sealant used for structural glazing applications. Sealant C complies with ASTM C1184, ETAG 002, EN 13022, and GB 16776-2005.

Table 1 provides an overview of the test program. Different test specimens, described below, were exposed to tension, compression and shear tests as well as tests with combined tension and shear loads. Furthermore certain tension tests with glass substrates were performed after artificial aging. Movement rates of 50 mm/min (v1), 0.5 m/s (v2), 1.0 m/s (v3), 2.5 m/s (v4), and 5.0 m/s (v5) were selected. Each test series comprised between three and six replicate specimens.

TABLE 1—Overview of test program.

Movement Rates

Load

Test Specimen (Cross-sectional area)

Sealant

0.00083

m/s

0.5

m/s

1.0

m/s

2.5

m/s

5.0

m/s

Tension

Type H0 (12 mm by 12 mm)

A

X

X

X

X

X

B

X

X

X

X

X

C

X

X

X

X

X

Type HW after

A

X

UV—Exposure

B

X

(12 mm by 12 mm)

C

X

Type HS (12 mm by 6 mm)

B

X

X

X

X

X

Type HL (24 mm by 12 mm)

B

X

X

X

X

X

Compression

Type H0 (12 mm by 12 mm)

A

X

X

X

B

X

X

X

C

X

X

X

Shear

Type M (12 mm by 12 mm)

B

X

X

X

X

X

Tension &

Type L

B

X

X

X

X

X

Shear

The test specimens were assembled and allowed to cure for 28 days at ambient laboratory conditions (23±3°C and 50±10 % r. h.). The specimens were then shipped to an external, independent test laboratory for high speed testing [36], and prior to testing were conditioned at ambient laboratory con­ditions for a minimum of 24 hours. In total, the specimens were conditioned (cured) for a minimum of 40 days prior to the testing.