Experimental researching on bending behaviour: Shear bond and deflecrtion of slabs composed of sheet and normal or lightweight concrete

Abstract

The use of lightweight concrete, instead of normal concrete, in these slabas presents an alternative which should be analysed specifically. Various standards and rules now reveal a different behaviour when using this type of concrete with respect to the use of normal concrete and this is a subject which has not been sufficiently developed. In this research, by considering two different types of sheet and two different types of concrete (normal and lightweight), we have aimed to compare the breaking and service behaviour of four different typologies (RIN, RIL, LIN and LIL). Each one of the four types has been tested by using four slabs with two different spans (2 and 4 m) grouped in pairs in isostatic condition and subject to point loads placed at quarter span. We therefore recommend that for the analysis of this type of slab and specially when using lightweight concrete or sheet to lead to low relations 1st slip load/breaking load, the consideration of the corresponding shear when concrete-sheet deparatiobn is produced, as a value to be taken into consideration in order to determine the shear that limits its capacity of resistance to shear bond and is considered in the french method we applied.