Study for improvements in design codes of timber structures regarding developments in time

This paper presents the results on experimental research of the bending creep behaviour of softwood timber beams in uncontrolled microclimate conditions (unheated building, winter climate in the region near the Baltic Sea) under different levels of a constant load not exceeding the proportional limit. Experimental evidence is produced to corroborate the Eurocode 5 conditions for predictions of creep effects under variable load. Deflection values of beams in four point bending are measured daily during 3 months simultaneously performing monitoring of the moisture content of the wood, relative humidity and air temperature. It has been observed that at the initial period the character of creep development differs significantly comparing it with later period till the end of the test. The linear equations are found as sufficiently good approximations for relationship creep versus time at the moderate load levels not exceeding the proportional limit.