Atmospheric Exposure Test Results of Lap Joints Fixed by Epoxy Adhesive
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The adhesive joint is one of the future possibilities to connect large steel members in buildings and bridge, but it is not clear what the resistance to the environment such as rain, oxide in the air, ultraviolet rays in the sunshine and so on is likely to be. In this report, atmospheric exposure tests of epoxy adhesive lap joints were conducted over 6 years to collect fundamental data for applying to large steel structures. The results are summarized as follows. (1) Shearing strength and fracture elongation of the paint coated epoxy joints is larger than that of the non coated epoxy joints over all periods. (2) The paint coated specimens showed only a shear fracture surface. But some of the non coated epoxy adhesive joints fractured mainly be cause of delamination of adhesive, and they had very small shearing strengths compared with shear fractured joints. (3) The paint coated epoxy adhesive joints can be used for large steel structures without considering the effects of the environment for at least in 6 years. (4) After 3 years, the shearing strength of the non coated epoxy adhesive joints, that fractured caused by shear of adhesive, become small due to effects of the environment. So it can be said that epoxy adhesive joints can not be used for large steel structures without paint coatings beyond 3 years.
- Transactions of JWRI
Transactions of JWRI 31 (2), 229-232, 2002-12