Experimental Research on Bearing Capacity of Fiber Cement Board Bottom Formworks and Fastenters of Steel Bars Truss Decks

Fiber cement board as the bottom formwork of steel truss deck is a new type of steel bars truss deck. In order to ensure the construction safety of steel bars truss deck with cement fiber board bottom formworks and provide a basis for revising the Code for Design and Construction of Composite Slabs (CECS 273︰ 2010), the bearing capacity of 36 long specimens and 36 short specimens of the steel bars truss decks with fiber cement board bottom formworks was tested. The results showed that the nail cap pulling failure, bottom formwork edge failure, and fastener failure would occur at the lateral edges of bottom formworks under the action of concentrated line load. Based on the analysis of experimental phenomena and data, the paper proposed theoretical and practical calculation formulas for nail cap pull-out failure and bottom formwork edge failure, and also provided standard test methods for the bearing capacity of connectors. The theoretical calculation formula given in the paper agreed well with the test results, while the results obtained by practical formula were conservative.