LONG-TIME CREEP TESTING OF PRE-CRACKED FIBRE

This paper describes pre-cracked synthetic and steel fibre reinforced concrete beams tested in five years with constant load. A second series with steel and composite basalt fibre reinforced beams is presently being carried out to confirm the results of the first series. The long-time load level is 50% of the residual strength at 1.5mm crack-width. All the tested beams show similar behaviour, i.e. that during five years the time dependent deflections are in the range 2 3 times the initial deflections, and these results are related to creep coefficient values calculated according to the creep model in Eurocode 2. Furthermore, mapping of the real fibre content is an essential part of the result evaluation, and has been used to explain the different behaviour of similar specimens. One consequence of the present results is that creep due to long time load should be accounted for in crack-width calculations.