Glued Composite Timber-Concrete Beams. I: Interlayer Connection Specimen Tests

• Published in: Journal of structural engineering (New York, N.Y.) N.Y.), 2010-10, Vol.136 (10), p.1236-1245
• Main Authors: Negrão, João Henrique Jorge de Oliveira, Leitão de Oliveira, Catarina Alexandra, Maia de Oliveira, Francisco Miguel, Cachim, Paulo Barreto
• Format: Article
• Language: English
• Subjects: TECHNICAL PAPERS
• ISSN: 0733-9445; 1943-541X
• DOI: 10.1061/(ASCE)ST.1943-541X.0000228

The composite interaction in timber-concrete beams is usually achieved with mechanical devices, such as shear connectors or plates driven into the materials. However, this connecting system shows some inherent inconveniences, such as the need for drillings and the limited mechanical improvement owing to interface slip. Using adhesives instead of mechanical connectors might attenuate these drawbacks. However, engineers are hesitant to apply adhesives for structural purposes, mostly because of the different thermohygrometric behavior of the adhesive and the connected material(s). This is particularly concerning timber because its hysteretic response to moisture may cause interface delamination. Therefore, as a preliminary stage for the test of composite beams, an extensive experimental campaign on small-size specimens was performed. The study focused on the shear strength at the interface and the role of some factors. Several series were considered by changing those parameters, and the results were compared. Both prefabricated and cast-on-site concrete specimens were considered. The results show that this system looks suitable for structural application, at least under steady dry conditions.