Duration of load effects on the splitting behaviour of timber loaded perpendicular to the grain by dowel-type connections

Abstract

The duration of load (DOL) effects of timber, and mainly the time-to-failure (TTF), are investigated numerous times in the past, and are now fairly well understood. The time-to-failure of connections is investigated mainly for joints parallel to the grain. Comparison of these connections and timber shows a rather similar TTF behaviour. Only a limited number of investigations are known that address the TTF effects of timber loaded perpendicular to the grain by connections with dowel-type fasteners, where splitting cracks are the primary cause of failure. From this it follows that the timeto-failure behaviour is more severe for these types of connections. The same applies for variations in temperature and relative humidity of the test environment. This paper describes duration of load tests on the splitting strength of timber loaded perpendicular to the grain by dowel-type connections, where the connections have introduced high stress levels since late 2006