Behaviour of headed shear studs in lightweight aggregate concrete under elevated temperatures

Composite steel-concrete structures are formed when a concrete component is connected to a steel component by means of a shear connector. The primary advantage of a steel-concrete composite structure is that the composite action takes advantage of the high tensile strength of the steel and the complimentary high compressive strength of the concrete [1]. Lightweight aggregate concrete (LWAC) consists of lightweight aggregates has an oven-dry density less than 2000kg/m3 [2]. Lightweight aggregate concrete has lower density and specific gravity than normal weight concrete (NWC) due to its porous aggregates [3]. Several studies have verified that lightweight aggregate concrete performs superior to normal weight concrete at elevated temperatures [4]. However, lightweight aggregates can be more expensive than normal weight aggregates. Nevertheless, the use of lightweight aggregate concrete is still feasible due to the reduced weight of the lightweight aggregate members which resulted in reductions in supporting members, foundations, formwork, transportation, labour and time [4]. Considering the superior thermal properties of lightweight aggregate concrete and its reduced density, there is a need to determine how the shear connection of a lightweight aggregate concrete composite structure performs under elevated temperatures.