Experimental Testing of a Portal Frame Connection Using Glued-In Steel Rods

Abstract

The use of glued in rods as a method for connecting timber has received much attention over the past decade with an increasing number of examples of their use in industry. The objective of this study is to understand the failure mechanism of a moment resisting portal frame connection in timber using glued in steel rods. A series of pull out tests are used to determine axial strength of glued in rods with varying anchorage length and bond line thickness. The results are compared with the current design equations and the discrepancies are highlighted. Further pull out tests using rods glued in at angles are used to assess the influence of lateral loading on the axial pull out strength. Small amounts of lateral loading combined with axial loading are seen to significantly reduce the pull out strength of glued in rods and splitting failures are seen at relatively low levels of load. The findings from the pull out tests are used to design a portal frame connection and the moment capacity is estimated using linear elastic analysis. Results from the destructive testing of the portal frame connection are presented and parallels are drawn between the observed behaviour in the angled pull out tests. The linear elastic analysis is found to accurately predict the failure load of the tested connection. The moment rotation (M - φ{symbol}) relationship of the portal frame connection is extracted from the measured test data. © RILEM 2014.