Post-installed mechanical fasteners in high strength and ultra-high strength performance concrete

Post-installed fastening systems are essential in structural engineering nowadays. Triggered by the increasing popularity of high strength concrete (HSC) and ultra-high performance concrete (UHPC), fastening in these basements is more and more frequently applied. This inevitably leads to the question of the applicability of conventional fastening systems and the corresponding design concepts with concrete showing a compressive strength of up to 200 N/mm². According to EAD 330232-00-0601, mechanical fasteners have to be placed in predrilled holes in compacted reinforced or unreinforced concrete without fibers with strength classes in the range of C20/25 to C50/60 in compliance with EN 206. This means that concrete strength class C50/60 also provides the reference for higher concrete strength; the impact of fibers and accompanying increase of concrete ductility is also excluded. Within the framework of this contribution it is intended to analyze the following aspects: (a) proof of applicability of various fastening systems in unreinforced and fiber-reinforced high strength concrete via experimental investigations and (b) making a statement regarding the currently valid European Assessment Document and provide experimental background for this issue.