Adhesively bonded timber-concrete composite structures: effect of nano-particles on interfacial bond and mechanical performance

Bachelor and Master Thesis

Description:
Composite structures of timber and concrete were originally introduced to substitute expensive materials as concrete and steel in floor constructions partly with local grown timber in a time of severe shortage of goods and energy in Germany in between world war 1 and 2. Today in Central Europe they are favored in refurbishments and in new timber constructions for qualities according to stiffness, noise insulation and fire safety. The construction method exploits the high compressive strength of concrete and the high tensile strength of wood fibres. The bending force that acts on the floor slab creates a compression zone in the upper part and a tension zone in the lower part of the section. In concrete-timber hybrid structures, one promising connection technique is using adhesion such as epoxy to connect the concrete and timber due to their resulting rigidity and ease of handling. In adhesively bonded timber-concrete structures, the stress transfer from the concrete to the timber component is via their interfacial adhesion, thus, the integrity of the hybrid structure is highly dependent on the quality of concrete and timber interfacial bond by the adhesion. How to improve concrete and timber interfacial bond strength becomes a critical issue to improve the short-term mechanical performance and long-term durability. In this study, nano-particles such as carbon nanotubes and graphene are incorporated into the adhesion in order to improve the overall structural performance and interfacial bond of adhesively bonded timber-concrete structure. This bachelor thesis will investigate the effects of nano-particles on interfacial bond and mechanical properties of timber-concrete composite hybrid structures.

The tasks include:

• Literature review of the use of nano-particles in adhesion and concrete
• Thermal stability of nano-particles incorporated epoxy adhesion by thermogravimetric analysis (TGA)
• Morphology analysis of concrete-timber interface using scanning electronic microscope (SEM)
• Single lap joint tests of timber-concrete component to identify the concrete and timber interfacial bond behavior
• Bending tests of timber-FRP hybrid components.

Expected:
Knowledge of material science and civil engineering; Basic knowledge of different testing machines; English language - communication skills; Self-motivation

The final thesis report can be written in English or in German. Because the mentor mainly speaks English, it is most useful for the student, to speak at least some English.

Contact: Apl. Prof. Dr. Libo Yan, l.yan(at)tu-bs.de