Repair of Structural Timbers. Part 2. Fire Resistant Repairs: Fid-Bau Portal

Repair of Structural Timbers. Part 2. Fire Resistant Repairs

C. J. Mettem / A. V. Page / G. C. Robinson

In 1991, as part of a larger research program on the repair of structural timbers, measurements were made on the fire resistance of three repaired glulam beams. Two of the beams had a new end section joined on to them by means of an internal steel flitch plate fastened with bolts. In these two beams all of the metal parts were covered by timber to protect them from fire and to maintain the original appearance of the beams, so far as was possible. In the third beam, a replacement end section made of epoxy resin was joined on with steel reinforcing rods which were bonded into the beam with epoxy resin. Each beam was tested under load in a furnace, in accordance with BS 476. One of the mechanically repaired beams and the beam repaired with epoxy resin survived for more than an hour before excessive deflection caused their eventual failure. It was concluded that, with proper design, timber beams may be repaired using either mechanical fastenings or epoxy resin repair techniques, in such a way that they can provide one hour's fire resistance. Such repairs are possible without unduly impairing the appearance of the structural timber members. (Copyright (c) TRADA 1993.)