Experimental investigation on the performance of partially encased beams at the elevated and room temperature

Partially Encased Beams (PEB) are composite stee[ and concrete e[ements Ihal presenl severa[ advanlages wilh respecl lo bare slee[ beams. They are usually buil! wilh hol rolled seclions wilh encased concrete between flanges. There are different design solutions, considering the arrangemenl of [ongiludina[ reinforcemenl of concrele, slirrup configuralion and material strength. The reinforced concrete between flanges is responsible for increasing fire resistance, [oad bearing and sliflness, wilhoul en[arging lhe overall size of bare slee[ cross seclion. Fire design, according lo European slandard EN1994-1-2 [1], is valid for composile beams, based on labu[aled melhods (considering simp[e supporting condilions and standard fire exposure) based on prescriplive geomelry lo a certain fire rating (lime domain). The simp[e ca[cu[alion melhod may a[so be applied lo PEB, using fire resislance on [oad domain, assuming no mechanical resistance af the reinforced concrete slab (considering simple supporting conditions and standard healing from Ihree sides). The eltecl of fire on lhe maleria[ characlerislics is laken inlo accounl, eilher by reducing lhe dimensions of lhe parts or by reducing lhe characlerislic mechanica[ properties of maleria[s