Study on Short-Term Rigidity of Precast Composite Slab with Steel Truss and Concrete

Composite slab by steel bar truss and concrete was a new style of floor slab. Because there were the small steel bar trusses in precast member, its short-term rigidity was higher than the normal composite floor slab. The structure was divide into four kinds, according to the relative location of the neutron-axis and the combined interface of slab; the relative value of the moment in first phase and the cracking moment of the precast slab. The different formulas to calculate short-term rigidity of precast member for four kinds were obtained. Through the models of composite slab by steel bar truss and concrete with different dimensions were established using finite element structural program, the formula feasibility was confirmed