Abstract

The effects of applied strain on sealants exposed to outdoor weathering were examined for two sealant formulations, Sealants A and C. Both static and dynamic strain was applied to the sealants during the summer in a Gaithersburg, MD outdoor location. Both sealants exhibited a reversible change in equilibrium distance. Stress relaxation studies on all samples revealed that, for Sealant A, two mechanisms affected modulus change; exposure without applied strain increased the modulus while additionally applied strain decreased the modulus. Only one mechanism that decreased the modulus was found for Sealant C. A 7 % dynamic strain and a 25 % static strain were observed to produce equivalent modulus changes in both systems.

Issue Section:
Research Papers
Keywords:
sealant, strain, modulus, outdoor weathering, characterization

References

1.
Onuoha
,
U. O.
, “
Durability of One-Part Polyurethane and Polyurethane-Hybrid Sealants
,”
Durability of Building Sealants
,
A. T.
 
Wolf
, Ed.,
RILEM Publications
,
Bagneux, France
,
1999
, pp.
235
–
251
.
2.
Brown
,
N. G.
,
Assessment of Joint Sealants Outdoor Exposure in Cyclic Movement Testers
,
Highett
, Ed.,
CSIRO Division of Building Research
,
Victoria, Australia
,
1965
, pp.
16
–
22
.
3.
Burstrom
,
P. G.
, “
Durability and Aging of Sealants
,”
Durability of Building Materials and Components, ASTM STP 691
,
P. J.
 
Sereda
 and
G. G.
 
Litvan
, Eds.,
ASTM International
,
West Conshohocken, PA
,
1980
, pp.
643
–
657
.
Google Scholar
Crossref
Search ADS
 
4.
Karpati
,
K. K.
,
Solvason
,
M. R.
, and
Sereda
,
P. J.
, “
Weathering Rack for Sealants
,”
J. Coat. Technol.
 0361-8773, Vol.
49
, No.
626
,
1977
, pp.
44
–
47
.
5.
Lacasse
,
M. A.
, “
Advances in Test Methods to Assess the Long Term Performance of Sealants
,”
Science and Technology of Building Seals, Sealants, Glazing and Waterproofing, ASTM STP 1254
,
J. C.
 
Myers
, Ed.,
ASTM International
,
West Conshohocken, PA
, pp.
5
–
20
.
Crossref
Search ADS
 
6.
Wolf
,
A. T.
, Ed.,
Durability of Building Sealants
,
RILEM Publications
,
Bagneux, France
,
1999
.
7.
Wolf
,
A. T.
, Ed.,
3rd International RILEM Symposium on Durability of Building and Construction Sealants
,
RILEM Publications
,
Seneffe, Belgium
,
2000
.
8.
Ferry
,
J. D.
,
Viscoelastic Properties of Polymers
, 3rd ed.,
John Wiley & Sons, Inc.
,
New York
,
1980
.
9.
White
,
C.
,
Embree
,
E.
, and
Buch
,
C.
, “
Design, Development and Testing of a Hybrid in-situ Testing Device for Sealant
,”
Rev. Sci. Instrum.
 0034-6748 https://doi.org/10.1063/1.1889234, Vol.
76
,
2005
, p. 045111.
10.
Taylor
,
C. R.
, et al, “
Nonlinear Stress Relaxation of Polyisobutylene in Simple Extension
,”
Trans. Soc. Rheol.
 0038-0032, Vol.
20
, No.
141
,
1976
, p. 1076.
11.
White
,
C. C.
,
Tan
,
K. T.
,
O’Brien
,
E. P.
, and
Hunston
,
D. L.
, “
Design, Fabrication and Implementation of Thermally-Driven Outdoor Testing Devices for Building Joint Sealants
,” unpublished.
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