Bond Properties in Lightweight Self-Compacting Concrete

The original development and use of Self-Compacting Concrete (SCC) in Japan started from the problem of the durability of concrete. Indeed, the reduction in the number of skilled workers, and the consequent poor compaction of structures, was a topic of great concern in the eighties, and helped the introduction of SCC. More recently, SCC is being commonly used in solid concrete slab in residential buildings for its excellent flowability. Additionally, to reduce structural self-weight without excessively affecting the slab thickness (which could represent a major issue in this applications), lightweight concrete represents a preferable solution. In this type of structure the development of anchorage or lap length becomes crucial, thus requiring a proper understanding of the bond mechanism. The result of an experimental campaign to assess bond properties for Lightweight Self-Compacting Concrete (LWSCC) are presented in this paper. The main investigated parameter is the bar size (ranging from 8 to 24mm) while the cover to diameter ratio and the bonded length to diameter ratio were kept constant. The experimental results are finally compared with code predictions.