Skip to Main Content
Skip Nav Destination
ASTM Selected Technical Papers
Durability of Building and Construction Sealants and Adhesives
By
A Wolf
A Wolf
1
Dow Corning GmbH.
?
Wiesbaden
Germany
Symposium Chairman and Editor
Search for other works by this author on:
ISBN-10:
0-8031-3480-0
ISBN:
978-0-8031-3480-5
No. of Pages:
419
Publisher:
ASTM International
Publication date:
2004

Stress relaxation uniaxial testing is used to define the behavior of elastomeric materials in their functional range. The stress-strain data obtained by this method are used in finite element analysis (FEA) to model the behavior of the material in a given application. The objective of this study is to determine the effect of aging on the uniaxial stress-strain properties of silicone sealants. This paper examines the material behavior changes that occur as these sealants continue to cure at ambient laboratory conditions. The study is intended as a first step toward developing simple working models that account for the effects of sealant aging in FEA modeling. Uniaxial stress relaxation testing was conducted on six commercially available silicone structural glazing, insulating glazing, and weatherproofing sealants in tension and in compression at temperatures of -20°C, 22°C, and 80°C. Testing was carried out immediately after cure, i.e., after three days for two-part and after 30 days for one-part sealants, and after an additional one-year storage period at ambient laboratory conditions. The test specimens were pre-loaded prior to testing in order to eliminate the Mullins effect. Testing was carried out over a strain range of-45–90%. The specimen was loaded to the desired strain level and then allowed to relax. The load at the end of the relaxation period was used to calculate the engineering stress. Coefficient of variance (CoV) was used to determine the significance of material property changes with continued sealant cure. No significant changes in engineering properties were observed for two sealants. For two further sealants, half or more of the test results were within CoV, and no clear trends in property drift could be derived. The changes in material properties of the final two sealants were well outside the CoV limit, and moderate to strong stiffening was observed.

1.
Vallabhan
,
C. V. G.
, “
Analysis and Design of Glass, Especially Laminated Glass, Used in Curtain Walls
,”
Glass Processing Days, 13–16 June 1999
,
Vitkala
J.
, Ed.,
Tamglass Ltd.
Oy, Tampere, Finland
,
1999
, pp. 187–195.
2.
Travis
,
H. S.
and
Carbary
,
L. D.
, “
Finite Element Analysis of a Structural Silicone Shear Bead Used in Skylight Applications
,”
Science and Technology of Building Seals, Sealants, Glazing and Waterproofing: Seventh Volume
, ASTM STP 1334,
Klosowski
J. M.
, Ed.,
ASTM International
,
West Conshohocken, PA
,
1998
, pp. 229–242.
3.
Iker
,
J.
and
Wolf
,
A. T.
, “
Secondary Stresses Induced by Shear Movement in Structural Glazing Sealants
,”
Materials and Structures
, Vol.
25
,
1992
, pp. 137–144.
4.
Wolf
,
A. T.
, “
Design and Material Selection Factors that Influence the Service-Life and Utility Value of Dual-Sealed Insulating Glass Units
,”
Ninth International Conference on Durability of Building Materials and Components - 9DBMC
,
Burn
S.
, Ed.,
CSIRO
,
Highett, Australia
,
2002
, Paper 106, pp. 281–300.
5.
Mullins
,
L.
, “
Effect of Stretching on the Properties of Rubber
,”
Rubber Chemistry and Technology
 0035-9475, Vol.
21
,
1948
, pp. 281–300.
This content is only available via PDF.
You do not currently have access to this chapter.
Close Modal

or Create an Account

Close Modal
Close Modal