Abstract:
Significance of the Proposed Work:
Industrial adhesives have become an important component of the
structural elements with the developing technology of new materials.
Adhesives that bond metals, plastics, FRP and other materials
have been used in transportation, industrial and marine applications.
Fundamental understanding of the bond behavior and load transfer
mechanisms of different adhesives is essential prior to their
use in civil infrastructure. The proposed research introduces
a new industrial adhesive.
It is intended to investigate the bond properties of the adhesive
which will be used in the design of structures.
Objectives
and Scope of Work:
The main objective of this research is to evaluate the engineering
properties of the new adhesive, which is referred to as adhesive "S". Mainly, the bond characteristics between composite-to-composite
and composite-to-steel materials will be investigated. As
a control product, an adhesive currently in use, referred to as adhesive "M", will be used and
tested using the same testing scheme as that for
adhesive "S". A comprehensive experimental program will be designed
using single lap-joint specimens. The setup for Single Lap-Shear
test is shown in Figure 1.The influence of high temperature
and creep on the bond characteristics will be examined. Strength
properties in cleavage peel by tension loading will be determined.
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Figure
1. Test setup
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Figure
2. Durability testing
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Research
Plan:
The proposed research includes mainly four experimental phases.
The first phase consists of lap shear tests to determine the
bond characteristics of two adhesives used between two Glass
Fiber Reinforced Polymer (GFRP) sheets. The work will be extended
to examine the behavior between GFRP and steel surfaces. At
the current stage a total of ten composite-to-composite lap
shear specimen have been tested. The failure modes will be
examined in order to determine which is most appropriate for
the typical application.
The
research also includes durability study. The test will consist
of a total of 76 specimens submerged in de-ionized water with
different PH values and different temperatures. A specially
designed insulated room has been constructed to house the
instrumentations which were built to subject the specimens
to the specified environments (Figure 2).
Also
Cleavage Peel tests for composite-composite and steel-composite
specimens will be conducted according to ASTM 3807 98. The
testing will be performed at room temperature. The last phase
of the experimental program consists of lap shear specimens
loaded to 400, 600 and 1000 psi for creep testing.
Impact
to the State of Practice:
In general, findings of this research program will enable
engineers to make more informed decisions regarding the use
of adhesives in different structural applications. Design
guidelines, as well as the bond characteristics of different
adhesives under severe environmental conditions, will be provided.
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