Steel–concrete bond behaviour of lightweight concrete with expanded polystyrene (EPS)

The experimental program presented in this paper was aimed to investigate the steel–concrete bond behaviour of lightweight concrete. The lightweight concrete was obtained by substituting part of the traditional coarse aggregates with beads of expanded polystyrene (EPS). The addition of EPS in the concrete mix could influence the bond behaviour with steel reinforcing bars, albeit the same strength of a normal concrete is reached. After different mixtures of normal and lightweight concrete with EPS have been tested in order to check the influence of several parameters on the compressive strength, two mixtures of lightweight concrete with EPS and one of normal-weight concrete were finally prepared for carrying out the bond tests. A traditional pull-out scheme was assumed for the bond tests of black and zinc-coated steel bars embedded in concrete blocks made of the three mixtures.