Bending reinforcement of timber beams with steel cross sections on the upper face

Abstract

A procedure for the reinforcement of timber floor joists in ancient buildings using steel U shape cross sections screwed to timber from the upper side is described. Bending tests of 3 groups of 10 beams were carried out obtaining the stiffness and load carrying capacity. The first one was composed by pieces of glued laminated timber of Spruce with 180x200 mm cross section; the second one was of Scots pine sawn timber with the same cross section; and the third one was 120 years old solid timber beams of genus Pine with 130x150 mm cross section. Each group was divided in two groups of 5 beams. The first sub-group was tested without reinforcement and the second one was tested with the steel reinforcement. The reinforcement increases the stiffness from 45 to 98 % and the load carrying capacity from 27 to 58 %.

Keywords

• timber
• steel
• finite elements method
• upgrading
• rehabilitation