Pullout strength of axially loaded steel rods bonded in glulam at a 45º angle to the grain

Julio Cesar Molina,Marcelo Rodrigo Carreira,Carlito Calil Junior

doi:10.1590/s1516-14392009000400010

Julio Cesar Molina, Marcelo Rodrigo Carreira + Show 1 more

Open Access

https://doi.org/10.1590/s1516-14392009000400010

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Journal: Materials Research	Publication Date: Jan 1, 2009
Citations: 8	License type: cc-by

Affiliation: Universidade de São Paulo

Abstract

This paper presents an experimental analysis of the pullout strength of bonded and axially loaded steel rods used as connector elements in log-concrete composite bridge decks. Static and cyclic tests were carried out to evaluate the fatigue of the connectors using two species of reforested wood, three types of commercial adhesives and three levels of wood moisture content. It was found that six failure modes (rod interface failure, timber interface failure, combined timber interface/rod interface failure, combined rod interface/timber substrate failure, rod failure, and adhesive failure) can occur in the geometry of a single test specimen. The results indicate the good performance of epoxy glued steel rod connectors for use in log-concrete composite bridge decks.

Highlights

The importance of preserving Brazil’s tropical rainforests has gained increasing recognition in the country in recent years
Six distinct failure modes were observed in the fatigue tests: a) Rod interface failure; b) Timber interface failure; c) Combined timber/rod interface failure; d) Combined rod interface/timber substrate failure; e) Rod failure, and f) Cohesive failure of the adhesive
Timber interface failure Predominant failure mode in the Eucalyptus test specimens with rods glued in with Compound epoxy adhesive (89% of failures), for the highest gluing moisture contents

Summary

Introduction

The importance of preserving Brazil’s tropical rainforests has gained increasing recognition in the country in recent years. Reforested pine and eucalyptus species grow rapidly and adapt to different climates. They are major sources of wood around the world, and especially in Brazil, where these species are abundantly available[1]. A connection system frequently used to join timber and concrete is the glued steel rod system, which is a low cost solution that is easy to implement. Brazil has no regulatory standards for the use of glued steel rod connectors in wood elements, such standards have existed for over twenty years in several Scandinavian countries and in Germany[2,3,4]

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