TY - THES

T1 - Technology Innovation in Direct Fastening on Concrete and Steel

AU - Tropper, Florian

N1 - embargoed until 15-03-2026

PY - 2021

Y1 - 2021

N2 - Quick and straightforward technologies are highly desirable in civil engineering. Among them, direct fastening has emerged as successful method for installation of functional or visual components by driving steel fasteners into structural materials like concrete and steel. Modification of the physical nature of such fasteners is the potentiality to improve fastening quality and thus safety, particularly when fastening to high-strength materials. To identify suitable material systems that may outperform standard bainitic fasteners, novel concepts for nails were generated and investigated by manufacturing prototypes and deploying them in fastening tests. For the first time, materials different from steel were used as fastener materials. Pure silicon nitride and Fe-based metallic glass nails predominantly fractured during penetration, albeit single successful fastenings were also observed for both cases. Nails out of cemented carbide WC/Co penetrated high-strength steels successfully but retention forces strongly scattered. Cemented carbide nails proved ineffective for fastening to concrete, but the combination of cemented carbide tip and steel shank seems advantageous. Furthermore, the concept of a NiTi shape memory alloy that was applied onto a nail shank to enhance anchoring in concrete faced multiple challenges, yet a promising redesign was established. In the process, good understanding of behavior of grooved nails was acquired.

AB - Quick and straightforward technologies are highly desirable in civil engineering. Among them, direct fastening has emerged as successful method for installation of functional or visual components by driving steel fasteners into structural materials like concrete and steel. Modification of the physical nature of such fasteners is the potentiality to improve fastening quality and thus safety, particularly when fastening to high-strength materials. To identify suitable material systems that may outperform standard bainitic fasteners, novel concepts for nails were generated and investigated by manufacturing prototypes and deploying them in fastening tests. For the first time, materials different from steel were used as fastener materials. Pure silicon nitride and Fe-based metallic glass nails predominantly fractured during penetration, albeit single successful fastenings were also observed for both cases. Nails out of cemented carbide WC/Co penetrated high-strength steels successfully but retention forces strongly scattered. Cemented carbide nails proved ineffective for fastening to concrete, but the combination of cemented carbide tip and steel shank seems advantageous. Furthermore, the concept of a NiTi shape memory alloy that was applied onto a nail shank to enhance anchoring in concrete faced multiple challenges, yet a promising redesign was established. In the process, good understanding of behavior of grooved nails was acquired.

KW - Direktbefestigung

KW - Befestigungselement

KW - Konstruktionswesen

KW - Werkstoffkonzepte

KW - Prototyping

KW - Nagel

KW - Beton

KW - Stahl

KW - Werkstoffwahl

KW - Direct Fastening

KW - Fastener

KW - Construction

KW - Material Concepts

KW - Prototyping

KW - Nail

KW - Concrete

KW - Steel

KW - Material Selection

M3 - Master's Thesis

ER -