Performance of statically indeterminate reinforced glass beams : experimental comparison with determinate systems and effect of a discontinuous glass section

A well-performing concept is the reinforced glass beam, developed in analogy to reinforced concrete. This concept proved its feasibility both in statically determinate and indeterminate systems, for a variety of parameters. However, the advantages of indeterminacy over determinacy in terms of structural performance and safety are not evaluated for this concept. This paper presents experimental results of similar statically determinate and indeterminate bending tests (i.e. with the same free span length and load point positions) on stainless steel reinforced laminated glass beams, made of annealed float glass (ANG). The interlayer is used to bond the reinforcement. With these results, a comparison is made to quantify the structural efficiency of the latter system, at two test temperatures and for two reinforcement percentages. In addition, statically indeterminate bending test results on ‘discontinuous’ glass beams are presented and compared to those of normal beams to evaluate the effect of local reduced beam stiffness on the system's load-carrying behaviour. The first investigation led to the conclusion that a 25% increase in ultimate capacity can be reached when applying a statically indeterminate system, provided that the reinforcement-to-glass bond is thoroughly designed for the specific conditions (enabling the beam to form all necessary plastic hinges). Furthermore, when the latter condition is fulfilled, a locally reduced beam stiffness has a limited effect on the overall load-carrying behaviour of the statically indeterminate beam system.