Abstract:In the prefabricated building, the steel truss composite slab is widely used as the main load-bearing member. However, the baseplate often cracks before installation on site, which leads to the failure of the composite slab. In this paper, a new type of two-way steel truss composite slab is proposed, that is, the transverse steel truss is installed on the traditional steel truss composite slab, so as to improve the bending bearing capacity of the composite slab. In order to investigate the effect of the installed transverse steel truss on the cracking state and mechanical characteristics of the composite slab, static loading tests were carried out on the two-way steel truss composite slab baseplate and the ordinary one-way steel truss composite slab floor, and the variation rules of the cracking moment, crack distribution, mid span deflection and strain with the load were obtained. The results show that under the same load, compared with the traditional one-way steel truss composite slab, the cracking moment of the two-way steel truss composite slab is larger, the crack development is slower, and the mid-span deflection and strain are smaller. The two-way steel truss can significantly improve the anti-cracking performance of the composite slab floor and effectively control the crack development.